Talk:Planet Nine/Archive 5

Planet Nine named possibly?
In the article it states that Planet Nine hasn't been named yet but is called "George" another name for the planet is "Mieko" or "Meiko". Could this possibly be it's real name? Fdmjiv (talk) 22:28, 17 September 2016 (UTC) If you find that name as one name that Planet Nine is being called please tell me on my talk page. Thanks! Fdmjiv (talk) 22:32, 17 September 2016 (UTC)
 * As near back as July, it hasn't been named yet. I'm pretty sure they want to conclusively find it before naming it. Primefac (talk) 22:41, 17 September 2016 (UTC)
 * Depending who wins the election, it will be named Hillary or Trump. Jehochman Talk 23:29, 17 September 2016 (UTC)

LOLFdmjiv (talk) 14:15, 24 September 2016 (UTC)
 * Please don't even joke like that, Jehochman, the mere thought is simply too depressing! — Huntster (t @ c) 01:11, 18 September 2016 (UTC)
 * Amusingly, the IAU's Naming of Astronomical Objects page does not seem to mention new full planets in our solar system. However, assuming the process is at least as elaborate as for dwarf and minor planets:
 * First the planet has to be properly discovered.
 * Then the orbit must be determined with some accuracy.
 * Then the discoverer (person or team) has the privilege of making the first formal name suggestion.
 * Ørjan (talk) 06:54, 18 September 2016 (UTC)
 * Planet McPlanetface? *hides in shame* — Huntster (t @ c) 21:15, 19 September 2016 (UTC)
 * Planet Nine McNineface seems more reasonable. Nergaal (talk) 12:31, 20 September 2016 (UTC)
 * <3 — Huntster (t @ c) 13:04, 20 September 2016 (UTC)

Ok thanks! I had no idea if that was true or it just randomly came out of my head. Fdmjiv (talk) 14:14, 24 September 2016 (UTC)

Shaping of the inner Oort cloud by Planet Nine
New paper. The interaction of Planet Nine with a preexisting disk produces a spheroidal distribution of objects with semimajor axes near 1200 AU due to interactions with its mean-motion resonances, an inclined disk between 1500 AU and 3000 AU and a warped disk beyond this. Agmartin (talk) 16:45, 29 September 2016 (UTC)

Generation of Highly Inclined Trans-Neptunian Objects by Planet Nine
Another one from Batygin and Brown Agmartin (talk) 16:31, 18 October 2016 (UTC)
 * High inclination objects acquire their unusual orbits via Kozai-Lidov cycles driven by Planet Nine and close encounters with Neptune. Perihelion is raised then later lowered while at high inclination. Encounters with Neptune can then lower semimajor axis below 100 AU. High inclination objects in two groups one with perihelion of 5 - 35 AU and dinclinations up to 100 degrees the other with perihelion around 10 AU and inclinations near 150 degrees. There is also a gap between these groups and no common plane like with Drac and Niku. Agmartin (talk) 21:00, 18 October 2016 (UTC)
 * Parameters used in simulations a9 = 600 AU, e9 = 0.5, i9 = 30deg, arg peri = 150 deg Agmartin (talk) 21:02, 18 October 2016 (UTC)

The point to note here, I think, is that in earlier simulations B&B had modelled all the giant planets as a single disk, so they couldn't use that model to simulate objects which come close to Neptune. In this new model, the giant planets are modelled as separate objects thus allowing them to model the trajectories of high inclination objects that come closer to Neptune. J mareeswaran (talk) 15:52, 20 October 2016 (UTC)

L91?
What's with this new L91 body?! New icy world with 20,000-year orbit could point to Planet Nine Tom Ruen (talk) 10:55, 18 October 2016 (UTC)
 * L91 never comes closer to the sun than 50 astronomical units (AU), or 50 times the Earth-sun distance. From there, it slowly crawls all the way out to 1,430 AU. This means it has a more elongated orbit than Sedna, another distant Pluto-sized object, whose closest approach is 76 AU and whose estimated far point reaches 937 AU.

It must be this uo3L91. Tom Ruen (talk) 11:05, 18 October 2016 (UTC)
 * The semimajor axis and perihelion match. I wish they had included the argument of perihelion. Agmartin (talk) 16:32, 18 October 2016 (UTC)


 * The Science article says L91 is in the plane of the SS. Anybody saw anything about its inclination? Nergaal (talk) 09:55, 19 October 2016 (UTC)
 * 4.2 degrees, (saw this on twitter) Agmartin (talk) 20:30, 19 October 2016 (UTC)

I think they are both the same objects going by the name of the observatory, telescope & researcher involved. J mareeswaran (talk) 15:54, 20 October 2016 (UTC)

New Objects
Six from Trujillo and Sheppard 2014 FE72, 2014 SS349, 2014 SR349, 2013 FT28, 2013 UH15, 2013 FS28.

Paper by them to show up soon? Agmartin (talk) 17:59, 29 August 2016 (UTC)
 * Paper at arXiv New Extreme Trans-Neptunian Objects: Towards a Super-Earth in the Outer Solar System

Some notes


 * another observation from this paper:
 * In a second paper, Brown and Batygin (2016) showing a possible secondary longitude of perihelion clustering 180 degrees away from main longitude of perihelion clustering for some simulations. This smaller population secondary longitude of perihelion clustering should generally take place at lower semi-major axes than most of the main clustering and it appears 2013 FT28 is in this secondary longitude of perihelion clustering.J mareeswaran (talk) 06:52, 18 September 2016 (UTC)


 * objects with q > 35 and a > 150 AU have argument of perihelion between 290 and 40 degrees, significant and six sigma level
 * objects with q 200 AU have argument of perihelion largely clustered in opposite direction (these are mostly objects with perihelia < 25 AU including some crossing Jupiter's orbit)
 * for objects with q > 35 and a > 150 AU longitude of perihelion is correlated with argument of perihelion, those with long peri 0 - 120 degrees have arg peri 280 - 360 degrees, those with long peri 180 - 340 have arg peri 0 - 40, significance of correlation 99.99%
 * their analysis including observational biases and stability of the finds the clustering of longitude of perihelion is likely real but marginal (page 17)
 * 71% of objects with q > 40 and a > 150 AU should have 50 < q < 75, odds of their survey finding three without one in this range ~2%, including other surveys assuming same biases (unlikely since theirs only followed up on objects at greater than 50 AU) odds 6x10^-11 or seven sigma Agmartin (talk) 21:12, 1 September 2016 (UTC)
 * "objects with q 200 AU have argument of perihelion largely clustered in opposite direction" Five of these 8 are the perpendicular objects noted in the original paper the remaining three probably aren't significant, which probably explains why they dropped the mention of them in the abstract of the latest version on arxiv. Agmartin (talk) 21:34, 15 September 2016 (UTC)

I see one new article among 2014 SS349, 2014 SR349, 2013 FT28, 2013 UH15, 2013 FS28. There's an orbital diagram here, with 2013 FT28 (aligned with P9) and 2014 SR349 (aligned with other eTNO). Tom Ruen (talk) 14:37, 3 September 2016 (UTC)

Another graphic is here:, i.e. showing orbits of 2014 FE72, 2014 SR349, and 2013 FT28. Tom Ruen (talk) 21:23, 7 September 2016 (UTC)

If we're adding these objects to the list, , , , then we need a graphic for them. Tom Ruen (talk) 12:08, 12 September 2016 (UTC)


 * I tried tracing the orbit ellipses from in Inkscape, but the text doesn't seem to work. Tom Ruen (talk) 13:18, 12 September 2016 (UTC)
 * Aug_2016_new_extreme_objects.svg

How does this look?



suggested changes welcome. Agmartin (talk) 19:40, 12 September 2016 (UTC)
 * It works for me. Could it be any larger? I wish we could show an inner circle of Neptune. I'm not against cropping the outer orbit of 2014 FE72 for space reasons. The main question is whether we want to follow the "new extreme objects" coloring approach, or this of just showing all the objects. It looks like 2007 TG422 was missed on the graphic I tried to trace. Tom Ruen (talk) 15:09, 13 September 2016 (UTC)

Larger image with Sun and Neptune added, I made the lines thinner so they could be distinguished from Neptune. Agmartin (talk) 18:05, 13 September 2016 (UTC)

Cropped version Cropped version

Agmartin (talk) 18:20, 13 September 2016 (UTC)
 * Much better. I liked the cropped version, just maybe a bit higher resolution. Tom Ruen (talk) 20:19, 13 September 2016 (UTC)
 * I added the cropped one to the article above the table. It would also be great if each object was shown in its current position around the orbit. Finally, what about the other 3 objects above not included? I see semimajor axis less than 250 AU. 2014 SS349 (a=142<250 AU), 2013 UH15, (a=172<250 AU), 2013 FS28, (a=196<250 AU). Tom Ruen (talk) 21:14, 13 September 2016 (UTC)
 * p.s. I compared the original one with cropped. It looks like the view direction (north-to-south or south-to-north is reverse between the two. Perhaps this should be clarified which one is which. Tom Ruen (talk) 22:55, 13 September 2016 (UTC)
 * Here's a crude recropping, rotating P9 on the right. flipping vertical, and adding direct labeling. Tom Ruen (talk) 00:30, 14 September 2016 (UTC)

Honestly,, it would probably be simpler and overall more useful to take your SVG attempt and file a request at Commons:Commons:Graphic Lab/Illustration workshop asking someone to pretty-please fix it (and to insert the Sun in the image). SVGs are always best for these sorts of images because they scale, are small, and can easily be translated when necessary. I tried to fix it, but my Inkscape-fu is zero and the code is too complex for manual text editing. — Huntster (t @ c) 00:55, 14 September 2016 (UTC)
 * Agreed SVG are better. Part of the problem is the traced image includes a slightly different subset of objects. ALSO I think the perspectives are a bit different, AND probably even the P9 representative orbit is somewhat different. So anyway, I'd trace a SVG from Agmartin's image if that's the set of objects we want to represent. Tom Ruen (talk) 02:04, 14 September 2016 (UTC)
 * I don't think tracing (of any variety) is the best way to go, if only for the sake of accuracy. Additionally, re-scaling/retooling the image every time a new object gets added would be annoying. When I made File:EN131090 with text.png, I used MATLAB to plug in the actual coordinates, which allowed for a very accurate reproduction. Maybe we should do the same for this; not only would it give accurate orbits, it would also be (relatively) easy to add new objects (plus it would be easy to add/subtract orbits to see what it would look like). It wouldn't be an SVG, but it would still look decent at high resolution. Primefac (talk) 02:24, 14 September 2016 (UTC)
 * Sure, I agree best for a orbit renderer to compute ellipse objects directly. It's just a little tricky to take a certain perspective and determine the 2D ellipse for each projected 3D orbit. Tom Ruen (talk) 04:54, 14 September 2016 (UTC)
 * The orbits I've plotted (using excel) are the ellipses as they would be seen if all of the objects were coplanar and using the data from the table. That's probably why they don't look quite like the other images, and why the sun looks kind of square. It shows the alignment and relative sizes of the orbits, which is what I expect those reading the article would be most interested in seeing. Agmartin (talk) 18:04, 14 September 2016 (UTC)
 * Incidentally, I looked back and saw this view from  which is nice for showing the current positions of the bodies, and the ellipse brightness fades, so you can tell the direction of motion. It would be nice to do something like this in SVG. Tom Ruen (talk) 23:15, 14 September 2016 (UTC)

Is it just me or the sun looks in these images a little bit too much "squared"? Not a big issue of course, just asking...--Alexmar983 (talk) 04:40, 14 September 2016 (UTC)
 * It's just too low resolution, and no antialiasing. Tom Ruen (talk) 04:55, 14 September 2016 (UTC)

p.s. This article also talks of "A seventh distant object, spotted by the Outer Solar System Origins Survey, was discussed by Michele Bannister", sourced here, listed there as uo3L91 is NOT included in the new list of objects. I tried overlaying some images, and its orbit is clearly unique from the new 3 ones listed, AND its apogee is much further than the 3 other objects listed at the top of this section, excluded by semimajor axis closer than 250AU. Anyway, it seems strange this object described in a March public lecture has not been publicly defined! Is there ANYTHING on that mystery object? OH, I see an article exists uo3L91, but largely unsourced. Tom Ruen (talk) 23:04, 14 September 2016 (UTC)
 * The DPS-EPSC abstracts list a talk about this object on October 16, I expect the data for it and other objects will show up at the MPC site around then. When I did a fit for this object I found a perihelion of ~50 AU and a semimajor axis of ~750 AU. Agmartin (talk) 16:32, 15 September 2016 (UTC)
 * Last year a bunch of objects from OSSOS showed up on the MPEC's on Sept 11. Agmartin (talk) 18:29, 15 September 2016 (UTC)


 * The red entries need a legend showing what they mean. Nergaal (talk) 20:31, 15 September 2016 (UTC)


 * I just want to point out that 2013 RF98 seems to be mislabelled as 2013 BF98 on the image on the left. Same for 2012 VP113 being mislabelled 2012 VP112. Headbomb {talk / contribs / physics / books} 09:55, 18 October 2016 (UTC)
 * , any feedback? Headbomb {talk / contribs / physics / books} 16:39, 20 October 2016 (UTC)
 * Good eye! I fixed them. Tom Ruen (talk) 16:56, 20 October 2016 (UTC)

Starshot Initiative
How is the Starshot Breakthrough Initiative going to identify the said structure? They are microspacecraft with very limited payload. BatteryIncluded (talk) 11:47, 21 October 2016 (UTC)


 * I see, about this section: Planet_Nine Tom Ruen (talk) 11:58, 21 October 2016 (UTC)
 * So the author meant the Breakthrough Initiatives, not the Breakthrough Starshot (spacecraft). BatteryIncluded (talk) 12:23, 21 October 2016 (UTC)
 * It must be! Tom Ruen (talk) 13:54, 21 October 2016 (UTC)
 * Thank you for the edit. BatteryIncluded (talk) 00:21, 22 October 2016 (UTC)

2014 UZ224
To preempt any speculation

Dwarf planet candidate 2014 UZ224 H=3.6, distance 91 AU only Eris and V774104 more distant.

Semimajor axis = 109 AU, not part of Planet Nine group. Agmartin (talk) 19:34, 11 October 2016 (UTC)


 * It looks to be a transitional member of the group- it's pretty close to the Nine group to be a coincidence. However, it seems Neptune has started to have an effect on it as well. exoplanetaryscience (talk) 23:27, 11 October 2016 (UTC)


 * Nothing special about this object, other than its mode of discovery - which was thru the Dark Energy Camera. It is claimed that DEC can be used to detect planet nine also. J mareeswaran (talk) 12:33, 26 October 2016 (UTC)

Reduced theoretical areas to search
Nothing to add to article now, since paper unpublished, but news! Tom Ruen (talk) 19:40, 26 October 2016 (UTC)
 * Closing in on a Giant Ghost Planet: Scientists have shrunk the hunting ground for the mysterious Planet Nine by half, SciAm October 25, 2016
 * 'So the strategy in the race is now largely a matter of reducing the search area by eliminating theoretical possibilities. In an as-yet unpublished set of about 100 new high-resolution computer simulations, Batygin says he and Brown have narrowed down Planet Nine's location to a roughly 600- to 800-square degree patch of sky.'

And there's an orbital diagram here, including L91, and sky search area diagram here. Tom Ruen (talk) 19:47, 26 October 2016 (UTC)
 * Objects beyond Neptune provide fresh evidence for Planet Nine SciMag, Oct 25
 * The orbital diagram three had a different orientation for P9, but Sedna and others matched, so I added L91 orbit onto the crappy low-res image until we can get something better. There were also a couple of other unlabeled smaller gray orbits there ignored. Tom Ruen (talk) 20:37, 26 October 2016 (UTC)


 * Update to the one I posted above last month Agmartin (talk) 21:37, 26 October 2016 (UTC)


 * Thanks! I remade the old one from it with a correct L91, in "standard orientation". Tom Ruen (talk) 22:20, 26 October 2016 (UTC)
 * User:Fauxtoez Added a "clean" version, very nice, although orbit lines might be a little too wide, and PNG would be a better format than lossy JPEG, in case more orbits added to it. Tom Ruen (talk) 23:35, 27 October 2016 (UTC)

Planets position
I calculated exactly the same position in 2013 to the east of Orion-

Brian Johnston — Preceding unsigned comment added by 206.172.0.204 (talk) 13:01, 27 October 2016 (UTC)


 * West of orion? Calculated in 2013?! Tom Ruen (talk) 23:38, 27 October 2016 (UTC)

Patience
Anyone got some to spare?

[https://twitter.com/plutokiller/status/792077053281472512?lang=en New Planet Nine paper submitted! Coming to your inbox soon. If you're one of the scientists doing the peer review. Otherwise: patience.....]

and this "@StartsWithABang oh hey it answers your argument of perihelion question. which is nice." Agmartin (talk) 20:12, 28 October 2016 (UTC)

Minor question about wording
"Batygin and Brown suggest that it may be a primordial giant planet core..." This may come across as some to suggest it is the core only; a super-earth rather than an ice giant like Uranus or Neptune. Perhaps some rewording is in order? 134340Goat (talk) 20:09, 25 October 2016 (UTC)
 * Part of the reason I ask is multiple sources assume the planet is a mega-Earth, other sources assume ice giant. It would be helpful if the opening paragraphs stated what Brown and Batygin's paper say 134340Goat (talk) 23:21, 30 October 2016 (UTC)
 * I doubt if the B&B's paper says anything about composition. At this point we only know the approximate estimated mass. Other details are not clear.J mareeswaran (talk) 02:41, 31 October 2016 (UTC)

Neptune size comparison
Nice picture comparing size to Earth, but is there one comparing its likely size to Neptune? I believe the most likely size for P9 is about 30,000-35,000 km in diameter. Is there something comparing it to Neptune, possibly Earth AND Neptune? I feel it would be beneficial to many readers. 72.231.228.215 (talk) 06:55, 19 November 2016 (UTC)


 * I added Neptune. This image apparently was scaled identically by pixels. File:Neptune,_Earth_size_comparison_2.jpg Tom Ruen (talk) 14:09, 19 November 2016 (UTC)


 * For Neptune, Earth size likely comparison, this picture may do, Neptune, Earth size comparison 2.jpg the file contains more. Having Planet Nine hypothetical radius as (13,000 to 26,000 km), and for Neptune (24,622±19 km), either one may be assumed smaller than the other. The only solid evidence we have for P9 existance is ″improbable orbital configuration of the group″ on the left side of the Sun,(see the above graphs in this page); a mass approximately $6 kg$. arround the red colored orbit. This mass may be provided by more than one single planet, who knows!. --Mpj7 (talk) 14:28, 19 November 2016 (UTC)

Mystery of Planet 9
On the science channel

A second video, this one is an excerpt from the Adler Planetarium full length sky show on Planet Nine, it includes an animation from a simulation of the extreme KBOs as influenced by Planet Nine. Agmartin (talk) 20:57, 3 December 2016 (UTC)
 * Very nice! Tom Ruen (talk) 18:38, 4 December 2016 (UTC)

Hill Sphere
What is calculated about the planet's hill sphere? Given its eccentricity stretching hundreds of AU, it may be prudent for a graph to be made, perhaps a line separating perihelon to aphelion's hill sphere? It must be simply enormous compared to Neptune's. — Preceding unsigned comment added by 107.77.223.34 (talk) 00:16, 6 January 2017 (UTC)

Given $$r \approx a (1-e) \sqrt[3]{\frac{m}{3 M}}$$ = 12.5 au, given e=0.6, M=2e30 kg, m=6e25 kg, a=700. Tom Ruen (talk) 06:29, 12 January 2017 (UTC)

Constraints on Planet Nine's Orbit and Sky Position within a Framework of Mean Motion Resonances
New paper Their results


 * Mass, m∼6−12M⊕, Semi-major axis, a∼654 AU, Eccentricity, e∼0.45, Inclination, i∼30∘, Argument of perihelion, ω∼150∘, Longitude of ascending node, Ω∼50∘, and Mean anomaly, M∼180∘. A range of sky locations relative to this fiducial ephemeris are possible. We find that the region 30∘≲RA≲50∘, −20∘≲Dec≲20∘ is promising.

Note the difference in the ascending node 50∘ vs B&B's 100∘ Agmartin (talk) 02:32, 23 December 2016 (UTC)

I just noticed the paper includes a link to a 3-D figure of their proposed orbit. Agmartin (talk) 02:36, 23 December 2016 (UTC)

This reminds me of the Shankmann paper


 * 5.2 An alternate interpretation of the results: As shown in Figure 4, for example, the time-averaged measure of clustering in the KBO arguments of perihelion, is almost always smaller than the present day value, In other words, sustained clustering that matches the present-day value is exceptionally diffcult to obtain. The fact that it is so challenging could be viewed as evidence against the planet's existence. Agmartin (talk) 20:40, 23 December 2016 (UTC)


 * Could this be an artifact of observational bias? When Planet Nine is at aphelion (probable), are we more likely to see the clustered objects, and not see the non-clustered ones? At aphelion aren't all the objects in low integer ratio mean motion resonances most likely to be at perihelion? Jehochman Talk 14:47, 25 January 2017 (UTC)


 * Aphelion isn't a single time, but a large fraction of its orbit. I don't know how many fewer would be close during the relatively shorter perihelion. All the objects observed are near perihelion because they would be too dim to view at any other time, so there must be hundreds of more similar bodies we can't see that follow the same orbits, or not if there is no real pattern and no P9. It would certainly be better to have 100 confirming objects than less than 10, but maybe the ones we see now are all we're capable of seeing. Tom Ruen (talk) 11:03, 26 January 2017 (UTC)


 * In Brown and Batygin http://adsabs.harvard.edu/abs/2016ApJ...824L..23B they found a low percentage of simulations matched all of their constraints (see figure 2) so maybe the extreme TNO population isn't quite as well aligned as they appear. This might mean there is some observational biases, though I doubt it is due to P9 being near aphelion since some of the objects probably have periods less than 1/3 of P9's. There is still the arrangement of the perpendicular objects objects which probably don't have the same observational biases since they are more scattered in the sky than the first six of the ETNO's. Some other effect may be missing, perhaps their upcoming paper will reveal what it is. Agmartin (talk) 22:11, 27 January 2017 (UTC)

Planet Nine from Outer Space
Lecture from December 7 by Konstantin Batygin — Preceding unsigned comment added by Agmartin (talk • contribs) 22:13, 27 January 2017 (UTC)

ETNOs in current locations
I finally got around to adding orbit paths to my astronomy software, and updated the orbits for the TNOs, all 9 in main table except uo3L91 which I didn't have full parameters. I picked a view location and orientation similar to the one given in the article (P9 in green). The first thing that struck me, of course, was to see how the current positions are all so close to perihelion, so statistically we know there must be hundreds of additional objects (whether they agree with these positions or not), but too far away (so far) to be seen. I added a close up image, top-right, with the 9 bodies labeled. I added a third view, from earth now, with P9 and coincidentally 5 of 9 of the TNOs. I included current distances there and magnitude estimates, and 3 are similar to what P9 might be, 23-24 magnitude. And a 4th image from 6000BC (When P9 maybe near perihelion), with 4 objects clustered in Virgo with magnitudes 33 to 36, undetectable! Tom Ruen (talk) 13:37, 30 December 2016 (UTC)


 * Thanks, I hadn't noticed before how clustered in the sky the first six objects found were. Some of that is because the alignment results in them being brightest in that part of the sky, but I wonder how much is observer bias. If extreme TNO's are often lost because the assumed orbits based on short arcs are wrong (I think this is called ephemeris bias) perhaps that location is good for following up several months later so they aren't lost before the second year. Agmartin (talk) 18:08, 30 December 2016 (UTC)


 * I decided to add the current-position graphics to the article, along with the wide view one with all the orbits. The orientation is slightly different, and its missing the 10th one without full parameters, but I think it's helpful. Tom Ruen (talk) 14:31, 11 January 2017 (UTC)

Here's one more simulation, adding the 5 high inclination orbits, all of them now within the orbit of Uranus. The view location over 1 million AUs away, so minimal depth perception. (I suppose I should try a 3D image for red-blue glasses!) Tom Ruen (talk) 17:57, 16 January 2017 (UTC)
 * [[File:Planet_nine-etnos_now-close2_Jan1-2017.png]]

Here's a rectangular sky plot of the current sky positions of most of 9 TNO in magenta (aphelion>250au), 10 TNOs in yellow (ap>150au), and 5 high inclination bodies in blue. A nice clustering near Cetuss! Tom Ruen (talk) 22:55, 27 January 2017 (UTC)
 * Planet_nine-150au-etnos_now-flatsky_Jan-2017.png

zooniverse project
http://www.planet9search.org - worth linking? Smkolins (talk) 18:41, 29 March 2017 (UTC)

recent video talks…

 * https://www.youtube.com/watch?v=CMCwezegPNg
 * https://www.youtube.com/watch?v=v-ktWBtt7sc

Linkable for points made? Smkolins (talk) 18:44, 29 March 2017 (UTC)

L91 = 2013 SY99
The longitude of perihelion I determined from the graphic in the SETI talk video was only off by 0.3 degrees. Pats self on back. :-P Agmartin (talk) 23:56, 6 April 2017 (UTC)

Now that that is out of the way new paper OSSOS: V. Diffusion in the orbit of a high-perihelion distant Solar System object Agmartin (talk) 01:09, 7 April 2017 (UTC)
 * lucky object 'Faint, uncharacterized objects are very difficult to recover and track: they are only imaged if they serendipitously fall within the wide MegaPrime field of view during observations to refine the orbits of the brighter characterized TNOs. The four months of serendipitous observations of 2013 SY99 in 2013 implied that it was plausibly on anactively scattering orbit. Agmartin (talk) 01:24, 7 April 2017 (UTC)

Consequences of a Distant Massive Planet on the Large Semi-major Axis Trans-Neptunian Objects
New Paper details once I have chance to read it. I've also read that Batygin has submitted a new one to arXiv, be on the look out for that. Agmartin (talk) 20:31, 17 October 2016 (UTC)

Simulated the orbits of clones of the observed objects rather than starting from a disk interacting with Neptune. Did not begin with objects in resonances since "resonance confinement is not the proposed mechanism for ω bar shepherding". Found:
 * the perihelia and inclinations oscillated
 * objects entered high perihelion and high inclination (sometimes retrograde) orbits
 * some shepherding of longitude of perihelion but clustering was not dominant feature after 2 Myr of simulation
 * observed clustering of argument of perihelion and ascending node not reproduced
 * much of population too high perihelia and inclination to be observed
 * estimate of mass need to reproduce observed population tens of earth masses
 * initial solid mass required 100s - 1000s earth masses
 * simulations produce high inclination high semimajor axis objects that are not observe (did they miss the 5 pointed out in Batygin & Brown?) Agmartin (talk) 19:49, 20 October 2016 (UTC)

My guess is that the reason for the difference between their results and B&B is the objects are not started in resonances (though some clones spend time in resonances). I did see another paper showing longitude of perihelion confinement without resonances. Agmartin (talk) 19:49, 20 October 2016 (UTC)


 * It looks like a peer review of B&B's hypothesis by doing their own simulations. Their conclusion seems to be that:
 * They are sceptical of the existence of p9 because it requires more such objects & they consider that to violate the current theories of evolution of planetesimal disk
 * Their explanation is that the alignment in ETNOs is a co-incidence that will go away as more objects are discovered.
 * IMO Bannister et Al's objections to P9 sounds very similar to B&B's objections to Madigan's self-gravitating disk. But with another paper speculating that existence of P9 implies a spheroidal disk of inner Oort cloud objects, & Bannister acknowledges that this possibility exists but dismiss it as unlikely.
 * My takeaway from this is that if this observed clustering is real & permanent then it implies either a massive self-gravitating disk or a spheroidal cloud that is generated by P9. (Which can supply or act as a source for these distant objects that exhibit the observed clustering characteristics. J mareeswaran (talk) 07:41, 21 October 2016 (UTC)

Here's their table of 16 objects, including 6 with a>250 (article list), and 10 with 150<a<250, but excluding the 3 new ones: 2014 SR349 2014 FE72 2013 FT28. Tom Ruen (talk) 05:25, 18 October 2016 (UTC)
 * The last two here are double-listed. Tbayboy (talk) 11:31, 18 October 2016 (UTC)
 * Oops, corrected! Tom Ruen (talk) 11:38, 18 October 2016 (UTC)


 * A previous paper by this group of authors that began with of a simulated disk of objects that are scattered outward has been updated with plot of argument of perihelion, ascending node, and longitude of perihelion vs semimajor axis (figure 5) that also shows no alignment. https://arxiv.org/pdf/1605.06575v2.pdf Agmartin (talk) 20:55, 26 November 2016 (UTC)


 * Looking at some of the plots available via the link on page 6 of the Shankman paper the objects that show alignment tend to have the alignment broken when they come back into Neptune's reach. So maybe what's needed to preserve the alignment may be some mechanism to lift the perihelia of the objects before Planet Nine takes control of their dynamics, for example, if their perihelia are lifted by a Kozai resonance while in resonance with Neptune then they might stay far enough beyond Neptune's influence when the perihelion returns to its low values. If they were in the Kozai resonance with the argument of perihelion centered at 270 degrees they could move toward 360 degrees as the perihelia were lifted, and possibly be near the 320 degrees that these values cluster around when dynamical control shifts to Planet Nine. How this previous lifting would happen without Planet Nine breaking the either resonance first I don't know, unless it occurs before Planet Nine entered its current orbit. Agmartin (talk) 21:59, 26 November 2016 (UTC)


 * Michele Bannister's link to a video of one of papers simulations. Agmartin (talk) 19:01, 11 January 2017 (UTC)


 * That video simulation certainly does show much "shepharding". But Batygin ran thousands of simulations, so something needs explaining. Tom Ruen (talk) 06:35, 12 January 2017 (UTC)


 * Some things that aren't included yet in the simulations I've read about; Neptune's migration, Planet Nine's migration during that period, the effect of the galactic tide on P9's orbit. If P9's orbit is changing or has changed it might affect resonant objects, for example, they might be captured into resonances, like Pluto, instead of just sticking like 2015 RR345. Agmartin (talk) 22:15, 12 January 2017 (UTC)


 * I was giving this paper a second look and noticed an interesting coincidence, the Sedna clones' perihelia start crossing the orbits of the planets after ~700 Myrs, about the time of the Late Heavy Bombardment. Agmartin (talk) 00:59, 28 April 2017 (UTC)

Observational bias and the clustering of distant eccentric Kuiper belt objects
New paper from the abstract


 * We have developed a method to rigorously estimate the longitude of perihelion bias for Kuiper belt observations. We find that the probability that the 10 known Kuiper belt objects with semimajor axis beyond 230 AU are drawn from a population with uniform longitude of perihelion is 1.2%. Combined with the observation that the orbital poles of these object are also clustered, the overall probability of detecting these two independent clusterings in a randomly distributed sample is 0.025%. While observational bias is clearly present in these observations, it is unlikely to explain the observed alignment of the distant eccentric Kuiper belt objects.

Agmartin (talk) 21:28, 14 June 2017 (UTC)

"In the model that best explains the observations, all stars form initially as wide binaries."
Might be a small details worth mentioning - Embedded Binaries and Their Dense Cores by Sarah I. Sadavoy and Steven W. Stahler Accepted 2017 April 28 (not sure of the publication name.) Smkolins (talk) 22:04, 14 June 2017 (UTC)

Comets
Planet Nine is included in some of the models in new paper Origin and Evolution of Short-Period Comets

Quote from the intro "Planet 9 (hereafter P9), hypothesized to exist on a wide orbit around the Sun (Trujillo & Sheppard  2014, Batygin & Brown 2016a), is included in some of our simulations (see  Section  3) to test its influence on the structure of the trans-Neptunian region and comet delivery. We find that P9 would enhance the flux of  HTCs  by ~30%. The inclination distribution of ECs (ecliptic comets) can be matched in a straightforward manner in a model without P9, but when P9 is included, it acts to increase the inclination dispersion of SDOs. This propagates into the inclination distribution of ECs, which then appears to be too broad to match observations" Agmartin (talk) 19:30, 26 June 2017 (UTC)
 * More from page 23 "The problems with P9 discussed above are related to the fact that the scattering disk at 50 < a < 200 au, which is the main source reservoir of ECs (Section 4.7), has significantly larger inclinations than in the model without P9. This happens because many SDOs interact with P9, with their orbital inclination being excited, and then return into the scattering disk with a < 200 au." Figure 5 on page 48 shows the distribution of a objects with Planet Nine but without the galactic tide and or stellar encounters, beyond the scattered disk with perihelia near 30 au this cloud represents objects dynamically controlled by Planet Nine. A sizable fraction of them have semimajor axes larger than Planet Nine. Agmartin (talk) 22:00, 26 June 2017 (UTC)

Planet Nine: the score card
New post at findplantenine


 * another post discussing inclined objects. Agmartin (talk) 17:30, 3 July 2017 (UTC)

OSSOS VI. Striking Biases in the detection of large semimajor axis Trans-Neptunian Objects
New paper from the Outer Solar System Origins Survey, a quote from the abstract


 * We demonstrate the striking and non-intuitive biases that exist for the detection of TNOs with large semi-major axes. The eight large semi-major axis OSSOS detections are an independent dataset, of comparable size to the conglomerate samples used in previous studies. We conclude that the orbital distribution of the OSSOS sample is consistent with being detected from a uniform underlying angular distribution. Agmartin (talk) 15:54, 19 June 2017 (UTC)

OSSOS page summarizing the paper Striking Biases Agmartin (talk) 16:15, 19 June 2017 (UTC)


 * Here are the objects from table 1. So the main difference is the main list has a>250au, BUT 3 new ones are >250! Tom Ruen (talk) 18:46, 19 June 2017 (UTC)


 * Mike Brown's response on Twitter.  Serendi pod ous  19:38, 19 June 2017 (UTC)

Plot (left) with location of the poles of the Extreme TNOs, similar to a this post on findplanetnine.com, with areas OSSOS had no or poor coverage marked. Agmartin (talk) 21:08, 19 June 2017 (UTC)
 * Here's this plot (below) on top of the findplanetnine.com plot. Tom Ruen (talk) 21:31, 19 June 2017 (UTC)


 * Some notes on individual objects in that plot, the two objects at 10 o'clock, one from OSSOS and one from Sheppard and Trujillo are both in the aligned group, the object at 7 o'clock has a semi-major axis of 1800 AU so it may also be influenced by the galactic tide. Agmartin (talk) 21:18, 19 June 2017 (UTC)


 * Added (above) 2 views of orbits, 4 OSSOS objects in orange with a>250au. With a side-view (not shown), I see none of the 4 orange objects have a similar inclination the proposed P9. Tom Ruen (talk) 13:40, 20 June 2017 (UTC)


 * Should we add the other 3 "new" objects (a>250au) to the article table, along with 2013 SY99? They've all now been added with MPEC designations and orbital parameters: . Tom Ruen (talk) 13:49, 20 June 2017 (UTC)


 * The 3 new objects are included. I see this search also lists all 13 objects now. There are 15 objects between 150 and 250.  Tom Ruen (talk) 15:49, 21 June 2017 (UTC)

article in Science discussing new objects. Agmartin (talk) 01:11, 22 June 2017 (UTC)

Tweet from Konstantin Batygin showing how objects fit with their simulations. Agmartin (talk) 01:15, 22 June 2017 (UTC)

Article by Ethan Siegal Agmartin (talk) 01:37, 22 June 2017 (UTC)

I see Batygin talked about the 4 new objects on June 30. Status Update (Part 1) Tom Ruen (talk) 00:54, 8 July 2017 (UTC)

15 eTNO with a>200 AU, q>35 AU
Doing some nonpermissible OR, being curious about objects to include (beyond current 13), I expanded the B&B parameters with 250>a>200 and found 4 objects, and reduced by removing 3535 AU, a>200 AU I considered this expansion since we want larger q to be far above Neptune, while a>250 seemed somewhat arbitrary, perhaps only defined because it isolated the original list of 6. But now that we have counter-cases anyway, seems better to include.
 * IIRC Mike Brown included 2000 CR105 with the other six somewhere, I don't recall if it was on his blog or one of the later papers. 2002 GB32 was plotted on Figure 1 of B&B as one of the dynamically unstable objects. Agmartin (talk) 15:40, 19 July 2017 (UTC)
 * Found it, the second paper Observational Constraints on the Orbit and Location of Planet Nine in the Outer Solar System mentions seven objects with a > 227 AU are aligned. It also mentions that 5 with a > 100 AU and q > 42 AU are also clustered 2000 CR105 is included in both groups. He also mentioned a lack of objects with 100 AU < a < 200 AU and q > 42 as part of the criteria used in that paper. However, since it was posted on arxiv Trujillo and Sheppard did find one of those objects 2014 SS349 and the OSSOS group added a second 2013 UT15. Agmartin (talk) 16:06, 19 July 2017 (UTC)

I plotted these objects as viewed from above the solar system, and viewed from the sun along the ecliptic centered away from milky way center. Viewed from the sun (near the earth), you can see most the objects are away from the milky way where its hard to see 23 magnitude objects among the bright star fields. I colored the anti-aligned objects red, and others blue, with hypothetical P9 green. I put boxes around the two objects with 25035, a>180 3 more objects appear: 2007 VJ305, 2013 UT15, 2003 SS422, all generally anti-aligned with existing objects above (in red). Tom Ruen (talk) 10:08, 19 July 2017 (UTC)

Here's the current positions of 19 eTNOs, adding 2003 HB57 q>35, a>160, showing a surprising clustering of current positions, possibly suggesting survey bias? Tom Ruen (talk) 12:08, 19 July 2017 (UTC)

Planet Nine cloud
Discussed in Origin and Evolution of Short-Period Comets beginning on page 19 and previously in Observational Signatures of a Massive Distant Planet on the Scattering Disk although not by name. An interesting note about this cloud, few objects would be in these orbits without the influence of Planet Nine. Instead of clearing its neighborhood Planet Nine has cluttered it. So if Planet Nine is found they may need to rewrite the definition of planets again. Won't that be fun? Agmartin (talk) 21:45, 19 July 2017 (UTC)

All caught up.
The article is now updated to include all the relevant papers I have seen on arxiv. Agmartin (talk) 22:01, 1 August 2017 (UTC)

IEEE
Here's an interesting new source about the computer science behind the search. http://spectrum.ieee.org/aerospace/satellites/is-there-a-giant-planet-lurking-beyond-pluto In August a couple Berkeley grad students are going to run a new algorithm over archived photos to add them together and thus identify extremely faint objects moving along the predicted orbital path of P9. This computing will only take a few days, but may generate ~10,000 hits that will have to be investigated. Jehochman Talk 15:35, 1 August 2017 (UTC)

Looks exciting! Also:
 * "Those odds are now steeper because the list of relevant oddball planetoids known to haunt the outer reaches of our solar system has lengthened: from 6 in early 2016 to 20, Trujillo says."
 * We have 13 objects using B&B's criteria q>30, a>250 AU, and none dated from 2016. I don't know Trujillo's criteria. Tom Ruen (talk) 18:19, 1 August 2017 (UTC)
 * Six known in early 2016, seven were announced since then, they may have others awaiting better determination of their orbits. I recall one mentioned at a distance beyond 100 AU with no other details being released. Agmartin (talk) 18:59, 1 August 2017 (UTC)
 * Reading the article more carefully: thirteen from B&B's criteria, plus the 5 perpendicular, possibly rounded up. Agmartin (talk) 16:23, 2 August 2017 (UTC)

Amusing Hoax
Breaking News: Planet 9 Found!


 * The mysterious and elusive ninth planet of our solar system that is believed to be in existence since 2014, has reportedly been located by a Mr C. Green of Hampshire, UK. Mr Green, an amateur astronomer, made the schoolbook-changing discovery using a Meade LightBridge 12"/304.8mm Reflector Telescope from his home observatory a month ago‎. ... If the discovery of Planet Nine, which has been dubbed as the most important astronomical discovery of a generation, is officially credited to Mr Green, he has vowed to name the planet after his cat, "Emoji"

Mr. Green appears to be a casino. Agmartin (talk) 19:30, 2 August 2017 (UTC)


 * I thought about using Planet Nine Found! as the title, but was worried it might be possible for people to throw things at me through the internet. Agmartin (talk) 19:33, 2 August 2017 (UTC)

Mass
According to this article, Brown's currently estimated mass for P9 is about 8 Earth masses, not 10+ as stated in this article. Source 134340Goat (talk) 03:03, 2 August 2017 (UTC)

More specifically, the article says this: Tom Ruen (talk) 20:54, 2 August 2017 (UTC)
 * "Although it is thought to be 8 to 10 times as massive as Earth and 2 to 4 times as wide, it seems to be maddeningly hard to spot." and later "So, if Planet Nine exists and is 10 times Earth’s mass, it must be within 25 degrees of the farthest point in its hypothetical orbit, he says. A smaller Planet Nine—Brown now favors a mass eight times that of Earth—would have 40 degrees of wiggle room to hide in."
 * Goddamn, I'm lazy. Still, probably notable enough to include in this article somehow, especially given it says Brown seems to find it more likely to be at 8 Earth masses (therefore making it harder to find) 134340Goat (talk) 00:56, 3 August 2017 (UTC)
 * There was a paper submitted by Batygin and Brown last October that I suspect the source of the diagram of the poles of distant object orbits in this post. I expect that is where we will see the details of why they prefer a lower mass, and also a smaller inclination as I saw in a video of one of their presentations. I recommend waiting for that paper. Agmartin (talk) 17:35, 3 August 2017 (UTC)
 * And this seems an interesting quote - “I actually think we will not discover Planet Nine by scanning the sky,” Brown says. “We could, but I think somebody will find it first in archival data,”…. Smkolins (talk) 09:54, 3 August 2017 (UTC)

Why is Planet Nine so large and yet so dim?
User:Headbomb has three times reverted my attempt to include a statement about how brightness for planets decreases with the fourth power of its distance, claiming "This claim is both 1) ill-defined and false 2) unsupported by references. This is WP:BRD stuff. You've been reverted, go to talk page and discuss."

Would anyone like to help me support this? I linked a calculation of planetary apparent magnitude, although you still have to look a bit to get the 1/16 brightness for double the distance. The relationship is approximate in the sense that the distance from the earth to planet is not identical to the sun to planet distance, although for distances of hundreds of AUs this is effectively true. I also noted that doubling the distance is about 3 magnitudes dimmer, although the exact brightness ratio for 3 magitudes is 100^(3/5)≈15.849. Tom Ruen (talk) 05:47, 5 August 2017 (UTC)
 * A planet moved twice as far from the sun will be 1/16th as bright, or about 3 magnitudes dimmer.


 * "The relationship is approximate in the sense that the distance from the earth to planet is not identical to the sun to planet distance". Exactly. Unqualified, the reader will think if you double Mars' distance, you'll cut its brightness to 1/16th, and that's just not true. Even worse when you think about Mercury or Venus.
 * The exact fraction you get by double the distance is not important, every one understand that things get dimmer as you move them away. Explaining the simplification made to get such a fraction will distract the reader with needlessly dense passages. The important point is made: Due to its extreme distance, we expect it to be at least 600 times dimmer than Pluto.
 * Also due to the extreme eccentricity, Planet Nine's brightness would vary quite a bit at perihelion (200 AU), than at aphelion (1200 AU), and by a lot more than a factor of 16. Headbomb {t · c · p · b} 05:59, 5 August 2017 (UTC)


 * So the statement can be qualified or clarified however you think is helpful, which can include a note reference to not clutter the paragraph. Reverting rather than improving is unhelpful. And the statement is true for P9's predicted elliptical orbit, so when it is near aphelion 1000AU vs 500AU it will be about 3 magnitudes dimmer. And as you say from 200 to 1200 AU, it could be 6^4=1296 x dimmer from perihelion to aphelion, or 7.8 magnitudes. Comparing to similarly sized Neptune would be more useful since Neptune is about the same distance as Pluto, and expected to be a similar size. Comparing to Pluto just adds to the mystery, why tiny Pluto much smaller and 600 times brighter. Tom Ruen (talk) 06:10, 5 August 2017 (UTC)


 * You may want to qualify the statement by pointing out that in the outer solar system the distance from the Sun to the object and the distance from the object to the Earth are similar enough that the more complex equation can be approximated by distance^4. Perhaps
 * "In the distant reaches of the outer Solar System a planet moved twice as far from the Sun will appear approximately 1/16th as bright, or about 3 magnitudes dimmer, as viewed from Earth."
 * with the equation and an explanation of why it can be approximated in this manner in a note. Agmartin (talk) 16:44, 5 August 2017 (UTC)
 * I'd much rather have a short note that the apparent luminosity (or whatever the technical term is for this) of post-Kuiper belt objects / TNOs / whatever as seen from earth varies as 1/d4 (assuming it is reflection-dominated), which can then be vulgarized as double distance = 16 less bright. Backed with references. But this is out of place in the main text. Headbomb {t · c · p · b} 17:10, 5 August 2017 (UTC)
 * Yes, luminosity is the wrong term. You could say apparent brightness, but really it is simply brightness. Tom Ruen (talk) 17:58, 5 August 2017 (UTC)
 * Here is a source: https://books.google.com/books?id=dTs2DQAAQBAJ&pg=PT10&lpg=PT10&dq="fourth+power"
 * That this planet has not been discovered yet should not strike anyone by surprise. Since the brightness of a body decreases by the fourth power of its distance from the sun, even an object as large as Neptune would be a million times dimmer than that.Wnmyers (talk) 07:52, 8 August 2017 (UTC)

High Inclination objects
A bit of OR (slaps wrist with ruler)

According to a search of JPL's small bodies database there are 16 asteroids with semimajor axis > 150 AU and inclination > 40 degrees. I have plotted the argument of perihelion relative to Planet Nine vs inclination and longitude of ascending node relative to Planet Nine vs inclination with figure 9 from Batygin and Brown 2016 as the backgrounds link1, link2. It appears to me that asteroids with semimajor axis greater than 300 AU follow the tracks from B&B about as well as the five on their plot even if when the perihelion is inside Jupiter's orbit, two have 3 < q < 5 AU ( 2005 VX3 and 2017 MB7 ) and two q < 3 (2002 RN109  and 2007 DA61 ). Unfortunately all were only observe for short arcs. I note the tracks from B&B are for objects with a > 500 AU and that when Sailinfest etal 2017 (mentioned in second paragraph of the Secular dynamics of extreme TNOs section) discussed perpendicular objects those with a > 300 AU crossed the orbits of the other planets. Agmartin (talk) 21:56, 8 August 2017 (UTC)
 * 2014 LM28 with a = 268 AU and q = 16.8 AU inc 85 degrees does not fit well, however. Agmartin (talk) 22:04, 8 August 2017 (UTC)
 * link1 and link 2 are changed to correct mistake made a mistake converting 0 - 360 range to -180 - 180 range, 2007 DA61 no longer fits tracks from B&B 2016. Agmartin (talk) 01:01, 10 August 2017 (UTC)

Two more papers
Evidence for a possible bimodal distribution of the nodal distances of the extreme trans-Neptunian objects: avoiding a trans-Plutonian planet or just plain bias?

Objects appear to avoid crossing the ecliptic at some distance, perhaps because their orbits are avoiding the orbit of Planet Nine.

Evaluating the Dynamical Stability of Outer Solar System Objects in the Presence of Planet Nine

Identifying range of semimajor axes and eccentricities that allow orbits of know ETNO's to remain stable even if their semimajor axes vary. Agmartin (talk) 18:54, 22 June 2017 (UTC)

Another one Non-resonant secular dynamics of trans-Neptunian objects perturbed by a distant super-Earth Agmartin (talk) 15:26, 6 July 2017 (UTC)

On the first paper, I extracted the Table 1 objects into a wikitable below. It's excluding 6 newest objects (2013 UT15 2015 GT50 2015 KG163 2015 RY245 2015 KH163 2015 RX245 ). (I colored green where Ω+ω aligned with P9, in [180,300], and yellow orthogonal) Tom Ruen (talk) 09:33, 10 August 2017 (UTC)
 * subscript b=barycentric orbital parameters, σ=standard deviation

Resonances
From a conference abstract by Bailey, Brown, and Batygin
 * "it has been proposed that resonant interaction between Planet Nine and distant, confined objects may inform the present-day semimajor axis and location of Planet Nine along its orbit, if the resonances at play can be identified. Inspired by this notion, we have carried out a suite of numerical simulations aimed at characterizing capture probabilities of Planet Nine mean-motion resonances, and have found that numerous high-order resonances successfully trap Kuiper belt objects, precluding a simple identification of the dominant commensurability. At the same time, our simulations show that resonant relationships are indeed key to maintaining long-term stability of confined KBOs, and breaking the resonant lock results in the rapid onset of dynamical instabilities within the distant Kuiper Belt."

While this runs counter to a number of papers discussed in the article, I'm waiting for it to show up on arXiv or in the press before adding it. Agmartin (talk) 17:16, 5 August 2017 (UTC)


 * It would be good when the above paper arrives to combine all talk of resonances in one section. It seems Batygin and Brown first brought the idea up, then Maholtra, Volk and Wang fleshed out their take on it, then Milholland and Laughlin, etc. There are two problems that I see with making a single section (or subsection) on resonances. The first is that the Maholtra material (and excellent table) is in the 'Alternate hyphotheses' section (and other stuff is in 'Subsequent efforts toward indirect detection'/'Optimal orbit if objects are in strong resonances'). The Maholtra/Volk/Wang info on resonances should move. The second problem is that Milholland and Laughlin's paper is oversimplified, as they specify a few possible resonant configurations for certain bodies. Assscroft (talk) 00:52, 8 August 2017 (UTC)
 * I was thinking of a mean-motion resonances vs secular dynamics section describing the two proposed mechanisms once that paper came out. Right now the indirect detection section is by paper because it I found it easier to add individual summaries as I read the papers. For the Milholland and Laughlin paper I stuck to the specific configuration because the graphic of that one is what showed up in the press. Agmartin (talk) 16:56, 8 August 2017 (UTC)


 * Here's a recording of the talk by Elizabeth Bailey, The Role of Resonances in the Search for Planet Nine linked from . Tom Ruen (talk) 02:03, 8 August 2017 (UTC)
 * At 9;34 she shows a plot of the chances of individual object being in N/1 and N/2 resonances, 1/4 - 1/2; and for six objects randomly chosen objects all being in N/1 and N/2 resonances, a few percent at most. Agmartin (talk) 16:42, 8 August 2017 (UTC)


 * part of another abstract, this from the upcoming DPS conference
 * "In this talk, we will characterize the dynamical processes at play, from semi-analytic grounds. Specifically, we will show that although the long-term survival of the clustered population of long-period KBOs is enabled by a web of mean-motion resonances driven by Planet Nine, it is the secular dynamics embedded within these resonances that regulates the orbital confinement and perihelion detachment of distant Kuiper belt objects. Moreover, we will demonstrate that the onset of large-amplitude oscillations of orbital inclinations is accomplished through capture of low-inclination objects into a high-order secular resonance and identify the specific harmonic that drives the evolution." Agmartin (talk) 21:34, 12 August 2017 (UTC)
 * That disappeared from the DPS abstracts but the paper is now on arxiv - Dynamical Evolution Induced by Planet Nine

Capture of free-floating planets
New paper Was Planet 9 captured in the Sun's natal star-forming region? from the abstract:


 * "We find that only 1 - 6 per cent of FFLOPs are ensnared by stars, even with the most optimal initial conditions for capture in star-forming regions (one FFLOP per star, and highly correlated stellar velocities to facilitate capture). Depending on the initial conditions of the star-forming regions, only 5 - 10 of 10000 planets are captured onto orbits that lie within the constraints for Planet 9. When we apply an additional environmental constraint for Solar system formation - namely the injection of short-lived radioisotopes into the Sun's protoplanetary disc from supernovae - we find that the probability for the capture of Planet 9 to be almost zero." Agmartin (talk) 16:33, 5 September 2017 (UTC)
 * I see a couple of articles that are confusing capturing a free-floating planet with capturing one from another star. Newsweek New Scientist. Agmartin (talk) 19:11, 11 September 2017 (UTC)
 * I was probably too harsh on New Scientist, they only mentioned capturing from another star, but didn't clearly point out that the free-floating planet capture is a third idea. Agmartin (talk) 19:38, 11 September 2017 (UTC)

Planet Nine: where are you?
New post at findplanetnine. Agmartin (talk) 20:33, 21 September 2017 (UTC)
 * A couple of quotes
 * We now know of about 10 of these anti-aligned objects, so can look at their longitudes of perihelion and get a direct estimate of the longitude of perihelion of Planet Nine (if you care about the details: we actually exclude the two most recently detected objects as they came from the OSSOS survey which has been shown to have striking biases in the objects that it finds). When we do this, we find a value of 235 with an uncertainty of 12 degrees.
 * And the good news is that can now estimate the node much more precisely. If we take those same eccentric distant Kuiper belt objects and look at their nodes, we find that Planet Nine has a longitude of ascending node of ~94 degrees. Agmartin (talk) 21:36, 21 September 2017 (UTC)

Another discussing the latest paper. Agmartin (talk) 21:03, 11 October 2017 (UTC)

TNOs and Centaurs, and detection
I think the article could make more clear the differences between Centaurs and TNOs. Are the minor planets mentioned in section Batygin and Brown (2016) - Clustering, Centaurs? Also for detection, since meteor impacts are traced back to their origin based on impact speed (at least for the Chelyabinsk meteor), are there any studies to use meteor origins to get a better clue of Planet 9s orbit (If origin could be traced to related regions)? prokaryotes (talk) 13:46, 14 October 2017 (UTC)

Oops
I was experimenting with a different arrangement of the article, in what I thought was my sandbox, but had wrong tab open. Sorry about the mess I made of it. Back to normal now, closing this tab. Agmartin (talk) 19:41, 13 October 2017 (UTC)
 * For the next time, you can undo back to a particular version in one edit by
 * selecting the Cur beside it in in View history;
 * choosing undo from the resulting diff view.
 * (For step 1, if there are other later edits you don't want to affect, you can also diff any two particular versions, although that increases the chance of an edit conflict in step 2.) --Ørjan (talk) 04:36, 14 October 2017 (UTC)
 * Thanks. Agmartin (talk) 17:15, 14 October 2017 (UTC)

DPS abstracts about Planet Nine

 * Debiasing the Distant Solar System Populations Using Pan-STARRS1
 * Biases in the OSSOS Detection of Large Semimajor Axis Trans-Neptunian Objects
 * Detection Bias for Trans-Neptunian Objects on Highly Elliptical Orbits with the Dark Energy Survey
 * A Wide Field Search for Extreme Trans-Neptunian Objects and a Super Earth in the Solar System
 * Mean-Motion Resonances and the Search for Planet Nine
 * The search for Planet Nine
 * Evaluating the Dynamical Stability of Outer Solar System Objects in the Presence of Planet Nine
 * Evidence for self-gravity in a massive Hills Cloud
 * Orbital Clustering in Trans-Neptunian Objects
 * Dynamics of a Possible Collisional Family of Extreme TNOs
 * Extreme Resonant Dynamics: the Dynamics of Extreme TNOs in Mean Motion Resonances With Planet 9

and from twitter, refering to Dark Energy Survey - [https://twitter.com/AstroCook/status/921052388571492352 Hamilton: detected 8 extreme TNOs, 2 news + 2013 RF98 have a>250 au. #DPS17] Agmartin (talk) 20:04, 19 October 2017 (UTC)
 * What is the meaning of the twitter statement. Two NEW eTNO? Who is Hamilton? (Third and 7th links above?) DPS17 is https://aas.org/meetings/dps49 ? Tom Ruen (talk) 09:53, 20 October 2017 (UTC)
 * Here's something: In search of the ninth planet Oct 17, 2017 Astronomers also have another newly discovered TNO to include in their indirect methods of detecting Planet Nine. The Dark Energy Survey collaboration, a large group of scientists including several U-M scientists, has discovered another TNO that has a high orbital inclination compared to the plane of the solar system: it is tilted about 54 degrees relative to the solar system's plane. ... In an analysis of this new object, Becker and her team have found that this object experiences resonance hopping as well in the presence of Planet Nine, showing that this phenomenon extends to even more unusual orbits.

Revised version of article
I have a rearranged and partially rewritten version of Planet Nine in my sandbox. You can view that, right? First, I have moved the summary back above the table of contents. Second, to address one of the reasons for the "too technical" notice, instead of being a list of result by a series of papers, I organized the first part with the answers to the questions Who, Where, What, Why, When, and How in mind. For the dynamics section I used the five pieces of evidence cited by Batygin and Brown in a recent NASA article as an initial outline. After describing the clustering that provoked the recent speculation about Planet Nine I describe what happens in simulations then describe the dynamics that produces these results, before moving on to the other effects. I decided to place the alternate hypotheses after origins because the low probabilities of the mechanisms proposed served as a good lead in. Those are ordered by most skeptical, i.e. no clustering in models or in observations, then from the least similar model with no planet, to a planet with objects in strong resonances, to the Trujillo and Sheppard that began recent work, and finally ending with some earlier models. Next is searches with telescopes, which I think most reader will find more interesting than the more technical indirect detection methods. I'm thinking of moving some pieces of the material in the latter section, for example that on dynamical stability of distant objects, up into the dynamics or simulation sections. And some of the optimal orbit if in strong resonances up to the Object in lower eccentricity orbit section. That depends if it can be done without making then cluttered or confusing.

Suggestions welcome. Agmartin (talk) 22:17, 18 October 2017 (UTC)


 * Since they are discussing Planet Nine at the DPS confernece in Utah I decided to put it up today. Agmartin (talk) 15:30, 19 October 2017 (UTC)
 * I think the TNO template should be added back. Notice I have no complete overview of your changes. prokaryotes (talk) 20:13, 19 October 2017 (UTC)
 * If I removed it wasn't intentional, that may be a change that was made between when I copied the article to my sandbox to begin editing and that I missed before I posted the revised version. Agmartin (talk) 21:36, 19 October 2017 (UTC)
 * As prokaryotes may be hinting, doing such a large rearrangement in a single edit makes Wikipedia's diff views (especially the default one, but also the improved wikEdDiff) nearly useless. I had to give up proofreading after the "Numerical simulations of extreme TNOs" section because wikEdDiff started locking up after that. --Ørjan (talk) 08:40, 20 October 2017 (UTC)
 * The article as previous written read more as a history discussing various papers instead of an article about Planet Nine. That made sense when it was a few papers but the way it has grown around that outline that the article had gotten unwieldy. I didn't see any way to make more readable to a general audience without first pulling it apart and reorganizing it. After reorganizing it parts obviously would need rewriting before it could be followed. Not being an efficient typist or an enthusiastic writer I didn't believe it would have been practical to revise the article piece by piece while others were also making changes so I used my sandbox instead. Agmartin (talk) 19:31, 20 October 2017 (UTC)


 * What I changed
 * material in general is back above TOC
 * Trujillo and Sheppard and de la Fuente Marcos moved down to alternate hypotheses, IIRC they are unchanged.
 * the original three alternate hypotheses are reordered but otherwise unchanged
 * what was the intro to the Hypothesis section is now in Previous models with additional planets
 * moved the George Forbes material there, and the pieces that discussed Sedna and 2012 VP113 are merged into one paragraph
 * changed title of Hypothesis section to Dynamical effects
 * its intro is modeled on numerous recent articles listing five reasons Batygin and Brown think Plant Nine exists
 * Orbital clustering and high perihelion objects is the previous Clustering section with brief discussion of T&S 2014 and a bit about Sedna and 2012 VP113 added
 * Simulation section renamed, largely rewritten, it describes what happens only, why is moved to next section
 * parts of what discussed perpendicular objects is moved to that section
 * most of what was in Planet Nine cloud is now in the final paragraph of this section
 * Secular and resonant dynamics of extreme TNOs is new section, I'm thinking about adding images
 * To be continued. Agmartin (talk) 18:11, 20 October 2017 (UTC)


 * Continued
 * Objects with perpendicular orbits is mostly rewritten
 * It mainly describes the dynamics
 * Rereading it there a couple of things I left out that I will add back in
 * High inclination TNOs and Solar obliquity are largely unchanged
 * Oort cloud and Comets merged
 * Most of material that was in Oort cloud that instead discussed the P9 cloud is removed
 * Origin is moved up but unchanged
 * From Searches for Planet Nine on down sections are relocated and renamed but almost all are unchanged
 * Batygin and Morbidelli paragragh of Secular dynamics of extreme TNOs removed as redundant since it formed basis of Secular and resonant dynamics of extreme TNOs section earlier in article
 * That's what I remember, you may be able to compare intermediate edits by viewing history in my sandbox Agmartin (talk) 19:31, 20 October 2017 (UTC)


 * Thanks, that seems to work better if slowly (apparently a single large move can break wikEdDiff), so far https://en.wikipedia.org/w/index.php?title=User:Agmartin/sandbox&diff=805213842&oldid=805213583 looks a bit fishy, did you mean to delete that? --Ørjan (talk) 07:53, 21 October 2017 (UTC)
 * "Simulations have shown that objects with a semi-major axis less than $150 AU$ are largely unaffected by the presence of Planet Nine, because they have a very low chance of coming in its vicinity." is shortened to "and little effect inside 150 AU" in Numerical simulations of extreme TNOs; "The simulation also predicts a yet-to-be-discovered population of high perihelion objects that have semi-major axes greater than $250 AU$, and orbits that would be aligned with Planet Nine. Although they may include high eccentricity objects the most stable of these objects would have lower eccentricities." is covered in Secular and resonant dynamics of extreme TNOs "The orbits of objects that are unstable, for example some that are initially aligned with Planet Nine, precess until parts of the orbits are tangent to that of Planet Nine, leading to close encounters. Some stable orbits do exist for aligned objects with larger eccentricities. Objects in these orbits have yet to be observed, however, and an additional perturbation would have been required to be captured in these orbits."
 * Do you think a specific mention of 2013 FT28 should be included? Perhaps in a note?Agmartin (talk) 16:01, 21 October 2017 (UTC)
 * Sorry, I didn't mean to critize the deletion per se, I just wondered, since the edit description was just "typo", and searching for parts of its text in the final version found nothing, whether it had disappeared due to an editing mistake. --Ørjan (talk) 04:56, 22 October 2017 (UTC)
 * Ah, I didn't look a the description I left with the edit. Agmartin (talk) 19:56, 22 October 2017 (UTC)

Did you add all (or most) of the content from the previous general section? I would prefer a general section which summarizes the gist. https://en.wikipedia.org/w/index.php?title=Planet_Nine&oldid=805331232 prokaryotes (talk) 12:53, 20 October 2017 (UTC)
 * Most of what was in the general section was above the table of contents when I copied it to my sandbox to rearrange. Other than the mention of George Forbes and the inclination diagram it is largely unchanged, though I did rewrite part of he first sentence of the second paragragh. I think the intro should stick to Planet Nine only so I moved the mention of George Forbes to 'previous models with additional planets' and I left out the inclination diagram because I think that is a simpler concept than what the person who added the 'too technical' box meant. I think the brief summary (I see it as the TL;DR version) above the table of contents is more useful to those who just want the basics and don't want to wade into an article as long as this has gotten. Agmartin (talk) 17:27, 20 October 2017 (UTC)

Image to add
I've uploaded this image to the Commons:

The curves are modeled on upper right part of Fig. 2 of Dynamical Evolution Induced by Planet Nine by Konstantin Batygin and Alessandro Morbidelli. https://arxiv.org/abs/1710.01804

After finishing this plot I overlayed the curves from B&M 2017 and determined that while they are similar they clearly do not match those in the diagram from B&M 2017.

The image is intended as an illustration to aid the description of the changes in the orbits of extreme transeptunian objects with time in first paragraph of Secular and resonant dynamics of extreme TNOs section of the Planet Nine article https://en.wikipedia.org/wiki/Planet_Nine#Secular_and_resonant_dynamics_of_extreme_TNOs

I was wondering would wikipedia consider this not to be entirely my work and delete the file? Should I claim it is Fair Use instead? Agmartin (talk) 20:11, 23 October 2017 (UTC)

New origin model
Circularizing Planet Nine through dynamical friction with an extended, cold planetesimal belt

Only skimmed so far, few quotes:


 * 'In recent simulations of planetesimal formation via the streaming instability performed by Carrera etal 2017, a massive (60 - 130 MEarth) planetesimal belt forms beyond 100 au. This ultracold belt of planetesimals, which we will dub a cryobelt forms early due to effcient photoevaporation in the outer regions of  the  disc.'


 * 'Out of all simulations with an inner edge of the cryobelt at 100 au, approximately 30% (11/35) were successful. For simulations with an inner edge of the cryobelt at 200 au the success rate was 20% (7/35).'

The simulations start with Planet Nine's perihelion at 30 AU, and interacting with Neptune, which might affect their success rate. The planetesimals form quickly so the model would work if Planet Nine is scattered out early, as they assume, and I guess it would also work late like in the Nice model. Now I'm wondering if the inclination instability Madigan proposed could still occur with Planet Nine in the midst of the disk. Agmartin (talk) 18:52, 24 October 2017 (UTC)

on "Temporary or coincidental nature of clustering"
I think it would be relevant to talk why in physics a new discovery requires a 5 sigma in order to be taken seriously. Meanwhile, some recent hyped "discoveries" with 3 sigma proved to be just noise. Such a ?debate?/analogy could be relevant to mention in this section, to show that things like this are not unique to this specific case. 86.123.22.216 (talk) 10:27, 29 October 2017 (UTC)
 * Since this isn't a "discovery" but a prediction, it doesn't seem clearly relevant to me. Tom Ruen (talk) 17:04, 29 October 2017 (UTC)
 * IIRC the initial 0.007% odds of the clustering of the original 6 was 3.7 sigma. I think the new discoveries including aligned objects and the one at ~90 degrees may have made the odds less steep and the sigma smaller. But I have read that the clustering of the original six was tighter than than they saw in simulations (see Fig 2 in https://arxiv.org/abs/1603.05712 where the success rate never leaves single digit percentages) so the clustering in the data may never reach 5 sigma. Agmartin (talk) 19:07, 29 October 2017 (UTC)
 * And one thing about the Shankman et al paper discussed in that section. I suspect the reason their results differ from Batygin and Brown's is that they are using real objects with one possible orbit of Planet Nine. They may be starting with the objects in unstable orbits because they are not in resonances with Planet Nine or are not phase protected using these initial conditions. Agmartin (talk) 19:47, 29 October 2017 (UTC)
 * I suppose a big difference between quantum physics and planetary astronomy is that you can actually see your targets in astronomy, while everything from a particle accelerator is statistical inference, although exoplanetology is largely back into the black box again. Tom Ruen (talk) 19:56, 29 October 2017 (UTC)
 * Is there anything on Wikipedia on the question? Its mentioned here Standard_deviation. I see an article at SciAm 5 Sigma What's That? Tom Ruen (talk) 20:01, 29 October 2017 (UTC)

New eTNOs
From one of the abstracts (click on online program, Tuesday, 216 and Thursday, 405 for others) of next weeks DPS meeting. I wonder when they will release the data.
 * Detection Bias for Trans-Neptunian Objects on Highly Elliptical Orbits with the Dark Energy Survey
 * "We report the discovery of several new "extreme" trans-Neptunian objects (ETNOs) with semimajor axis > 150 AU discovered using the Dark Energy Survey (DES). This currently ongoing survey is entering its fifth planned year of operation on the 4m Blanco telescope in Chile and is imaging 5000 deg2 in the grizY passbands to a limiting magnitude of r~23.8. " Agmartin (talk) 21:39, 10 October 2017 (UTC)

Another one mentioned here
 * Evaluating the Dynamical Stability of Outer Solar System Objects in the Presence of Planet Nine
 * "We also announce the discovery of a new large semi-major axis, highly-inclined TNO, found in the Dark Energy Survey (DES) data. This new object’s orbit places it in the same population as was used to predict the existence of Planet Nine, and so this new object also helps constrain the orbital elements of the proposed Planet Nine." Agmartin (talk) 21:43, 10 October 2017 (UTC)

The Becker et al paper calls the new ETNO 'Caju' (but offers no mpl designation), orbital details: a = 450 AU, e = 0.92, i = 54 degrees. (https://aas.org/files/resources/dps49_becker.pptx) Assscroft (talk) 20:07, 24 October 2017 (UTC)
 * They often don't submit the data to MPC until after the paper discussing it is accepted. I see their other new one pe82, with a ~320 AU and anti-aligned like most of the others, in the ppt. Agmartin (talk) 20:51, 24 October 2017 (UTC)
 * Thanks! I see 'Caju' on slide 9, with its orbit drawn, and it says it fits the P9 set. Also reading plots argperi≈350°, long-asc-node≈133°, so that's enough to construct an orbit, just not a current position. I imagine they're looking for precovery images to improve the orbital parameters? Tom Ruen (talk) 02:21, 25 October 2017 (UTC)
 * Archived press conference available here: https://aas.org/media-press/archived-aas-press-conference-webcasts Agmartin (talk) 16:12, 25 October 2017 (UTC)

Guest post by Stephanie Hamilton on Planetary Society Blog Then vs. Now: How the Debate Over a Distant Planet in the Solar System Has Evolved includes image of orbits of 15 objects including Caju and ws301y4a. Agmartin (talk) 16:59, 30 October 2017 (UTC)

I think the main problem with this article...
is that it doesn't tell a story. It's just a list of different hypotheses. No wonder people are finding it hard to read. Orbital mechanics is complicated and people need to be drawn in. I would suggest going with a more historical approach, and focus more on the people involved.  Serendi pod ous  21:49, 25 October 2017 (UTC)
 * I would add a very accessible/readable/understandable summary to every key section, followed by the physics involved. Cheers, BatteryIncluded (talk) 22:55, 25 October 2017 (UTC)
 * I thought the historical approach that the article had before I rearranged it was what it made it look like a list of different hypotheses. That's why I moved the Trujillo and Sheppard, de la Fuente Marcos, and other history down; and so the first part of the article would be focused on Planet Nine. Agmartin (talk) 16:53, 26 October 2017 (UTC)
 * The problem is how the article progressed. Each new nugget of information was added as it became known. If and when Planet Nine is discovered, it needs to be entirely reworked. Leitmotiv (talk) 20:11, 26 October 2017 (UTC)

Personally, if that matters at all, I find this article fantastic, and for the most part well-ordered (and fascinating). It's a credit to Wikipedia. No idea if I'm in the minority in this opinion. Occasionally the 'research paper updates' need to be reorganised by theme, but that will never be apparent as they come in. Assscroft (talk) 01:06, 31 October 2017 (UTC)
 * You're definitely in the minority here, because Wikipedia isn't editing for Wikipedians. It's editing for the general public or layman. Sure this article is great for astronomers, but for the general reader this goes down as easily as a pint of caster oil. User:Leitmotiv


 * Those who are "improving" this article with endless techno-bable and math, this is one more reminder: Wikipedia is not a manual, guidebook, textbook, or scientific journal, Make technical articles understandable. Quoting: "Every reasonable attempt should be made to ensure that material is presented in the most widely understandable manner possible. If an article is written in a highly technical manner, but the material permits a more understandable explanation, then editors are strongly encouraged to rewrite it.
 * Quote from WP:What Wikipedia is not: #7 "Scientific journals and research papers. A Wikipedia article should not be presented on the assumption that the reader is well-versed in the topic's field. Introductory language in the lead (and also maybe the initial sections) of the article should be written in plain terms and concepts that can be understood by any literate reader of Wikipedia without any knowledge in the given field before advancing to more detailed explanations of the topic."
 * A request was placed as a header in the article and it has been consistently ignored. As stated above in this section, a reasonable request is to add a very accessible/readable/understandable summary to every key section, followed by the physics involved. A second alternative is WP:Blow it up and start over, which looks very tempting right now. Thank you, BatteryIncluded (talk) 16:32, 15 November 2017 (UTC)
 * Sorry, I thought I was addressing that (yes, I did read it before making the additions) by explaining some terms that were used but have no articles on wikipedia to link, for example phase protection, which previously was just thrown out there with no explanation, and how Planet Nine produces what is observed in simulations. The math is in notes, which I was under the impression that few people actually read, but I included in case someone wanted to confirm details without searching for them in the papers. The last physics course I took was one semester as a college freshman back in the 1980s, I've tried to explain as much as I could at that level, I thought these days they covered things like angular momentum, torque, and precession in high school. I've included diagrams that I've referred to in the explanations, and tried to paint a picture in the readers' minds where there wasn't room for one. What may look like fussy details in the last paragraphs of the secular dynamics and resonant dynamics sections was material that previously was scattered through several paragraphs before that I thought would appear more relevant there than in isolation. Perhaps I should rename Dynamical effects, Evidence of Planet Nine, and move the dynamics to the end if it is scaring people.Agmartin (talk) 22:11, 15 November 2017 (UTC)
 * You are doing a very good job at softening the technical terms into a more comprehensible language. There will always be some technical language required to explain the geometry and orbits, but I find that all or most of the key terms are explained early in the article. Thanks. It is a monumental task. BatteryIncluded (talk) 15:30, 19 November 2017 (UTC)

Chaotic Dynamics of Trans-Neptunian Objects Perturbed by Planet Nine

 * arxiv.org Sam Hadden, Gongjie Li, Matthew J. Payne, Matthew J. Holman
 * Observations of clustering among the orbits of the most distant trans-Neptunian objects (TNOs) has inspired interest in the possibility of an undiscovered ninth planet lurking in the outskirts of the solar system. Numerical simulations by a number of authors have demonstrated that, with appropriate choices of planet mass and orbit, such a planet can maintain clustering in the orbital elements of the population of distant TNOs, similar to the observed sample. However, many aspects of the rich underlying dynamical processes induced by such a distant eccentric perturber have not been fully explored. We report the results of our investigation of the dynamics of coplanar test-particles which interact with a massive body on an circular orbit (Neptune) and a massive body on a more distant, highly eccentric orbit (the putative Planet Nine). We find that a detailed examination of our idealized simulations affords tremendous insight into the rich test-particle dynamics that are possible. In particular, we find that chaos and resonance overlap plays an important role in particles' dynamical evolution. We develop a simple mapping model that allows us to understand in detail the web of overlapped mean-motion resonances explored by chaotically evolving particles. We also demonstrate that gravitational interactions with Neptune can have profound effect on the orbital evolution of particles. Our results serve as a starting point for a better understanding of the dynamical behavior observed in more complicated simulations that can be used to constrain the mass and orbit of Planet Nine.
 * Interesting how they can get clustering for a 1 Earth mass planet without them reaching anti-alignment. Agmartin (talk) 22:05, 20 December 2017 (UTC)

No Planet Nine?
Spotted on twitter:

Daniel Fischer‏ @cosmos4u Eek, have radio astronomers killed the #planetnine postulated by @kbatygin and @plutokiller?! Just learned of an upcoming paper based... 1/3 1:11 PM - 25 Oct 2017 from Cologne, Germany

Daniel Fischer‏ @cosmos4u Oct 25 ... on precision pulsar timing which nails down the barycenter of the solar system with enormous precision. The known planets show ... 2/3

Daniel Fischer‏ @cosmos4u Oct 25 ... clearly visible timing effects - but there are none from #planetnine where there should be. Paper out in a few months - stay tuned. 3/3

Mike Brown‏ @plutokiller Oct 25 Replying to @cosmos4u @kbatygin can't wait to read! difficulty, I think, is that P9 is essentially not moving and that pulsars aren't sensitive to a stationary tide. Maybe.

Konstantin Batygin‏ @kbatygin Oct 25 I agree w @plutokiller, but there might be at least an interesting constraint in there

Jonathan Hochman‏ @Jehochman Oct 26 This https://arxiv.org/abs/1008.3607 says no results for Uranus or Neptune. If not sensitive to those two, how to measure P9?

Mike Brown‏ @plutokiller Oct 26 well, that WAS 7 years ago. there should be a ton of new high quality data.

Jonathan Hochman‏ @Jehochman Oct 26 It would be funny if they said impossible and then you pull out a picture...

Mike Brown‏ @plutokiller Oct 26 yes! also, we're willing to be proven wrong. if they can do it that is support important.

https://twitter.com/cosmos4u/status/923280935025610753 Agmartin (talk) 17:00, 30 October 2017 (UTC)
 * And yet there are so many indicators for another big planet in our solar system (Solar obliquity, missing big planet compared to other star systems...) Why are there no recent spacecraft missions to map our solar system in more detail? prokaryotes (talk) 18:55, 30 October 2017 (UTC)
 * The data from Gaia will take years to process, and it has enough accuracy that it should be able to do what you're asking. It just requires researchers to look for the right stuff. Primefac (talk) 19:01, 30 October 2017 (UTC)
 * I see it says there "When Gaia entered regular scientific operations in July 2014, it was configured to routinely process stars in the magnitude range 3 – 20" so maybe objects dimmer than 20 will be ignored, including P9? Tom Ruen (talk) 02:32, 31 October 2017 (UTC)
 * Thinking about this, for the effects of Planet Nine to be detectable they would need to see a change in velocity that did not fit a model of the solar system without Planet Nine. For example changes in the velocity of the barycenter due to Planet Nine's velocity changing with time as it moves in its orbit, steady motion due to Planet Nine wouldn't be distinguishable from the Sun's motion among the stars. Or they would need to detect unexpected motions of the other planets like that found in the Cassini data, if that actually exists. Agmartin (talk) 17:05, 31 October 2017 (UTC)
 * My impression is we'd have lots of evidence of P9 if we had centuries of data, but the effects are too small in the short term. I imagine flinging out 10,000 microprobes in all directions with telemetry data as they go beyond pluto could tell us alot, effects like the Pioneer anomaly, but it would still take a couple decades, and surely telescopes will find a large planet faster. Tom Ruen (talk) 06:45, 1 November 2017 (UTC)
 * That's actually a really good idea. Bit more productive (though less exciting) than using those probes to get to Alpha Centauri. Primefac (talk) 12:10, 1 November 2017 (UTC)
 * P9 would change where the barycentre is. If you calculate the barycentre from the known major masses and assume the minor stuff (like the Oort cloud and small asteroids, in terms of the effect on the barycentre) are evenly distributed, then you could predict the path of, e.g., Mars. If Mars then follows a different path from the prediction, then then predicted barycentre is off, and you could (in theory) get the actual barycentre from the orbit. The difference points you to the missing mass (or balance thereof, if there are multiple missing major masses). So you don't really need the long timeline to wait for P9 to move to see its effect on the barycentre. If you have precise enough measurements, and lots of computing power. I think that's what they were trying to do with the Cassini measurements at Saturn. Tbayboy (talk) 14:32, 1 November 2017 (UTC)
 * I don't see barycenter as a primary factor. How do you even compute that except by the mass-position sum of all know bodies?! Perturbation doesn't need any assumptions about centers, rather it looks at cyclic longitudinal shifts, which requires long periods of data collection. It is surprising anomalies of Cassini could be caused by P9 out at 1000AU, although really I think it would be more the entire Saturn system shifting minutely from expected positions. So this seems more of a tidal force (decreasing with the third power of distance), with P9's gravity is slightly stronger at Saturn than earth IF P9 happens to be on the same side of the sun. Tom Ruen (talk) 22:42, 1 November 2017 (UTC)


 * I would also think that the effects on TNO's lessens over time, making detection and attribution harder. Bottom line, unless that study is accessible we are left with speculations. prokaryotes (talk) 19:06, 1 November 2017 (UTC)


 * Hopefully they find this thing's coordinates by late 2019, and then use the James Webb Space Telescope to take excellent pictures and measurements! Jehochman Talk 23:15, 15 November 2017 (UTC)

A dynamical approach in exploring the unknown mass in the Solar System using pulsar timing arrays Figure 3 shows the upper limits for the mass of unknown massive object at different distances to the Solar System barycenter but only extends to ~50 AU. Agmartin (talk) 17:18, 16 February 2018 (UTC)
 * Turns out this is not the paper @cosmos4u was referring to. Agmartin (talk) 21:12, 16 February 2018 (UTC)

New paper soon[ish]
Mike Brown @plutokiller 5 hours ago
 * As of yesterday(!) we now have statistically rigorous calculations of best fit orbit and mass of P9 and, critically, uncertainties on all of these parameters. Along with that comes a rigorous calculation of a probability that that is no P9: 0.01%
 * (papers with all of the details coming soon[ish] to an arXiv near you)
 * https://twitter.com/plutokiller/status/955099713308475392 Agmartin (talk) 21:03, 21 January 2018 (UTC)
 * Any paper yet?!? Jehochman Talk 03:21, 7 March 2018 (UTC)
 * I haven't seen anything on arxiv yet. Agmartin (talk) 21:51, 7 March 2018 (UTC)
 * As in Talk:Planet_Nine, words like "soon[ish]" and "stay tuned" should be taken with a grain of salt when it comes to publication dates. I'd not be surprised if the Pulsar timing paper takes another 6 months (the author has to finish other work first). It's similar for this one. But I have asked Mike Brown on Twitter, if it doesn't get burried and I get a response I'll tell you.--Renerpho (talk) 06:54, 13 March 2018 (UTC)
 * There was a paper Brown had submitted back in Oct 2016 that I thought was one of the two mentioned. Agmartin (talk) 21:35, 13 March 2018 (UTC)
 * I asked Mike Brown. He says the papers in question are not ready yet: https://twitter.com/plutokiller/status/973618807771025408 --Renerpho (talk) 22:57, 13 March 2018 (UTC)

#TNO2018
There was a workshop in Coimbra, Portugal this week discussing transneptunian objects. http://www2.mps.mpg.de/services/coimbra/ On twitter see hashtag #TNO2018

Today Planet Nine was one of the topics. Some relevant tweets

Michele Bannister @astrokiwi
 * .@StephHamy820 using @theDESurvey difference imaging for TNO discovery. Most of 200 objects at i>10 deg. Three objects with q > 35, a > 250 au thus far #TNO2018. working on characterizing observational bias for @theDESurvey analysis. Three extreme TNOs found at greatest point of sensitivity #TNO2018. one detection in DES is a bright r ~ 21.5 (H=4.3) extreme TNO, a = 450 au, i = 54.1 deg, q = 35 au #TNO2018. simulations of this TNO with J. Becker show dramatically different behaviour with/without an extra distant planet #TNO2018

This one is already in the article (in the table; it has been nicknamed "Caju"). --Renerpho (talk) 20:00, 29 March 2018 (UTC)

Dr. Sam @sundogplanets
 * Holman: testing Planet 9 idea with ranging data from New Horizons spacecraft and from very old observations of Pluto scanned. Finds a patch of sky where fits are improved if you add a giant planet tugging on Cassini (not NH, oops) or Pluto. #TNO2018. Holman: the residuals he used for fitting in his paper are actually wrong! #TNO2018. showing dynamically how P9 could align TNOs (has to do with resonance stability, from Hadden et al. paper). Says there will be temporary resonant sticking, NOT long term res. stability #TNO2018

Mike Alexandersen @Mikea1985
 * Holman looking for a planet in the residuals of Plutos motion (over 100 years of data) other bright TNOs (up to decades of data) and Cassini spacecraft data (meter-scale accuracy over several years). #TNO2018. Holman different groups find different residuals, so it's unclear that this actually provides constraints. One set of residuals (which he claims might be overfitted), hardly allows any additional planet anywhere. #TNO2018. Holman can consistently rule out most of the sky, but cannot consistently find a "best fit"/"most likely" area. #TNO2018

Michele Bannister @astrokiwi
 * Holman exploring a completely different approach for modelling mass in outer Solar System, using improved orbit of hundred-year arc on longest-known TNO, Pluto, (needed for trajectory of @NewHorizons2015) #TNO2018. using an old idea (Hogg et al. 1990s). orbits are tidally distorted by a distant planet. Can it be constrained by residuals from fitting orbits of Pluto & 500+ other TNOs? #TNO2018

Dr. Sam @sundogplanets
 * Trujillo has a prediction for where planet 9 should be on the sky based on stability simulations of "extreme" TNOs and different planet 9 orbits #TNO2018

Dr. Sam @sundogplanets
 * Sheppard: VP & Sedna are in very different part of a-q space than anything else in solar system. Lower q may have gotten there thru resonances, but not these 2. #TNO2018. Oo! New high-q TNO, discovered at 83 AU #TNO2018. shows with a certain planet 9 orbit, it will stay confined in long. peri #TNO2018. Found another big TNO (possibly top 10) and it has a moon and ALMA data, so they'll know for sure soon how big it is #TNO2018

Stephanie Hamilton @StephHamy820
 * Sheppard: New ETNO with perihelion of 65au, aphelion of 2000au. Nice! #TNO2018

Michele Bannister @astrokiwi
 * Sheppard: large distant TNO survey; use Subaru & Blanco for discovery, Magellan & DCT for recovery. Reduced down to two images for discovery rather than three, allowing more sky to be covered #TNO2018. trying to cover more sky to make a survey that is more uniform in longitude of perihelion. 97 discoveries at d > 50 au (only track these ones). New TNO with 3-year arc, q = 65 au, d=83 au, Q ~ 2000 au, long-term stable orbit #TNO2018. Sheppard new TNO has a ~ 1100 au, reasonably large uncertainties still. #TNO2018

The new high-q TNO is probably the object we know as V774104. There has been some confusion about this object, see here and here. Some mistakes happened during in the announcement, so the object's internal designation is different. I'd be cautious to include this information in any Wikipedia article, because 1. there is no official confirmation yet, and 2. Brown et al. haven't been able to include it in their calculations (they also don't have the details). --Renerpho (talk) 20:00, 29 March 2018 (UTC)
 * I agree about not adding it to the article yet, I thought it was too early to add details from the pptx file about 'caju' to the table, but seeing that has it mentioned in several articles and that its orbit was included in an article at the planetary society I didn't object when it was. Agmartin (talk) 20:32, 29 March 2018 (UTC)

Mike Alexandersen @Mikea1985
 * Kavelaars (@jjkavelaars): We argue against others not because we dislike them, but because we're scientists. It's our job to question and scrutinize theories and claimed results. #TNO2018. unfortunately it's very difficult to get modelers to give you their simulation outputs so that you can test the models (for example with the @OSSOSurvey survey simulator). #TNO2018. "Again, I'm going to show the same figure as Chad and say the opposite." With time the alignment in 150-250 au has gone away, and the claimed alignment has shifted to 250+ ah. Kavelaars predicts with time that alignment will disappear too. #TNO2018. the biases for small semi-major axis is completely different from that for large semi-major axis. You can't use a lack of bias in one to assume a lack of bias in the other. "You're putting apples and peanuts together." #TNO2018. come to Victoria in May 2019 for a "New Horizons in Planetary Science" meeting sponsored by @almaobs . #TNO2018 Agmartin (talk) 19:28, 29 March 2018 (UTC)

So still no P9. Nergaal (talk) 20:48, 29 March 2018 (UTC)

AAS Division Dynamical Astronomy conference is this week. This abstract is relevant to Planet Nine


 * The prevalence of resonances among large-a transneptunian objects
 * By carefully analyzing the astrometric data of all known large semimajor axis objects, we show that a very large fraction of the objects are in fact likely in high-order mean-motion resonances with Neptune. This prevealence for actually being resonant with Neptune would imply that hypothesized planets are problematic as they would remove the detached objects from these resonances. Instead, we favor a view in which the large-a population is the surviving remnant of a massive early scattering disk, whose surviving members are sculpted mostly by diffusive gravitational interactions with the four giant planets over the last four gigayears, but whose initial emplacement mechanism (in particular: perihelion lifting mechanism) is still unclear but of critical importance to the early Solar System's evolution.
 * http://adsabs.harvard.edu/abs/2018DDA....4910301G

Also spotted this on twitter:
 * @lukedones
 * Gladman: Many TNOs with semi-major axes > 100 AU are in high-order mean motion resonances with Neptune, including 10:1, 20:1, and 36:1. #DDA49
 * https://twitter.com/lukedones/status/985989872941907968

A 36:1 resonance would be at ~327 AU, possibly (474640) 2004 VN112 Agmartin (talk) 21:38, 16 April 2018 (UTC)

Shepherding in a Self-Gravitating Disk of Trans-Neptunian Objects
New paper appears to be claiming that a massive disk with modest and varying eccentricity can produce a cluster of objects anti-aligned to it by preventing their precession. I think that's what they are claiming at least. Agmartin (talk) 17:20, 20 April 2018 (UTC)
 * Looking at it more closely, the points with no precession are the neutral position at the centers of the curves which they plot in a different manner than Batygin and Brown did. In this article their disk is co-planar with the planets. Agmartin (talk) 21:23, 20 April 2018 (UTC)

P9 and IBEX: Interstellar Boundary Explorer


I can't figure out how does P9 and the streak on IBEX map align. Can someone help? If P9 is real and has a meaningful magnetic field, then the termination shock seen in IBEX should show signs. Nergaal (talk) 09:00, 29 April 2018 (UTC)
 * Image at this link has some constellations. Agmartin (talk) 20:27, 29 April 2018 (UTC)
 * So P9 is almost opposite to the Solar Apex? Nergaal (talk) 22:18, 29 April 2018 (UTC)
 * If Planet Nine's path in the article is correct it would be roughly opposite the heliospheric nose, I suppose that would be called the tail. There might be some natural noise in that direction that would interfere with detecting it the way you hope. Agmartin (talk) 18:33, 30 April 2018 (UTC)

barycentric vs heliocentric
Where were the numbers for the barycentric orbits found? Are they from the minor planet center, JPL's small body database, or somewhere else? Agmartin (talk) 20:45, 7 May 2018 (UTC)

The Generation of the Distant Kuiper Belt by Planet Nine from an Initially Broad Perihelion Distribution
New paper by Tali Khain, Konstantin Batygin, and Michael E. Brown examines whether which object remain stable after Planet Nine is captured on its proposed orbit starting with either a narrow perihelion distribution (similar to scattered disk objects) or a broad distribution due to their perihelia also being raised by nearby stars. Agmartin (talk) 18:46, 1 May 2018 (UTC)

And blog: Planet Nine makes some KBOs go wild May 7 Tom Ruen (talk) 21:44, 7 May 2018 (UTC)

Orbit diagram
I tested a SVG orbital chart, including the 13 known TNOs with hypothetical Planet Nine. I added a background grid for scale, with 100 AU fine units, and 1000 AU coarse units. I also rotated for Ecliptic 0 up, Ecliptic 90 left, which is ~160 degree rotation from the old chart. The SVG doesn't show current positions since useless at this scale, or at least if labeled. I won't put in article for now, since orientation not consistent with close up image.
 * Planet nine etnos.svgPlanet nine-etnos now-new2.png
 * Strangely, my browser shows the original SVG with a black background, but Wiki rendering has transparent background. I admit black background isn't clearly desirable anyway. Tom Ruen (talk) 08:32, 14 April 2018 (UTC)
 * p.s. This original diagram,, for uo3L91/2013 SY99 shows ecliptic zero right, and 90 degrees up. Tom Ruen (talk) 09:14, 14 April 2018 (UTC)

This is my one of first posts, so I might get the talk page format wrong, and this post is kind of old, but I'll still respond. I think this diagram should incorporate the two TNO's with q > 30 AU and semi-major axis > 220 AU, which are (148209) 2000 CR105 and 2015 RY245. (semi-major axes at 227 and 221 AU respectively) Note the difference between 2015 RY245 and 2015 RX245. (They are different objects.) I believe RY245 is the object "os513" seen here. https://twitter.com/astrokiwi/status/994983595835056136 2015 RY245, like 2015 GT50, is one of those "weird" objects. Ardenau4 (talk) 23:01, 2 June 2018 (UTC)

Edit: Apparently the MPC has the semi-major axes of CR105 and RY245 at 220 and 223 AU. I also forgot to mention (82158) 2001 FP185 (a = 226 AU, the article lists it as an SDO) Ardenau4 (talk) 23:22, 2 June 2018 (UTC)

New eTNO
I expect more data will show up soon at minor planet center

Michele Bannister @astrokiwi I'll finish by showing you our newly reported extreme TNO: this tiny world is on a vast, detached orbit with a=283 au (red), never coming closer than 39.5 au to the Sun. I wonder what past stories it will tell. https://twitter.com/astrokiwi/status/994983595835056136 Agmartin (talk) 19:38, 11 May 2018 (UTC)
 * Looking at the diagram its longitude perihelion is between 2015 GT50 and 2015 KG163, and trying to visualize where it would fit in the diagram on the main page at aphelion its orbit would be close to tangent to Planet Nine's orbit, interesting. Agmartin (talk) 20:06, 11 May 2018 (UTC)
 * I'll update an orbital diagram when it is official. Will it get a name soon? I assume it'll be on this list when it's registered. Tom Ruen (talk) 16:49, 3 June 2018 (UTC)
 * I was wondering why most of the objects haven't shown up at the minor planet cener, perhaps they are waiting for more papers to be accepted first. Agmartin (talk) 15:36, 4 June 2018 (UTC)
 * I put in the parameters for uo5m93 from the table, and made image above right. Tom Ruen (talk) 17:53, 3 June 2018 (UTC)
 * Thank, turns out its orbit is not as close tangent to Planet Nine's as I thought. Agmartin (talk) 15:32, 4 June 2018 (UTC)

Caju
A paper will be out soon at arXiv, DISCOVERY AND DYNAMICAL ANALYSIS OF AN EXTREME TRANS-NEPTUNIAN OBJECT WITH A HIGH ORBITAL INCLINATION. The referenced eTNO 2015 BP519, was the one nicknamed Caju. Tom Ruen (talk) 19:32, 9 May 2018 (UTC)
 * We report the discovery and dynamical analysis of 2015 BP519, an extreme Trans-Neptunian Object detected by the Dark Energy Survey at a heliocentric distance of 55 AU and absolute magnitude Hr=4.3. The current orbit, determined from an 1110-day observational arc, has semi-major axis a ≈ 450 AU, eccentricity e ≈ 0.92, and inclination i ≈ 54 degrees.
 * --> q=35.249±0.078, Q=862.73 AU
 * I wonder if the other two will be released at the same time. Agmartin (talk) 19:58, 9 May 2018 (UTC)
 * Juliette wrote "We have a few more extreme objects in the pipeline, and I'll send you an email once they pass our internal checks and we can release them!" Tom Ruen (talk) 20:05, 9 May 2018 (UTC)
 * The orbital parameters for 2015 BP519 are up: JPL and MPC Tom Ruen (talk) 03:41, 10 May 2018 (UTC)
 * 3D Orbit Agmartin (talk) 16:34, 10 May 2018 (UTC)

Out now link Agmartin (talk) 16:14, 16 May 2018 (UTC)

https://www.popsci.com/kuiper-outer-solar-system#page-3  Nergaal (talk) 20:05, 1 June 2018 (UTC)

It's 'pe82' that perhaps shouldn't be in the table at 'Hypothesis and the calculated effects/Extreme trans-Neptunian objects'. While Caju is now well-documented, the fact that pe82 was found by the DES is not stated in the Powerpoint referenced (Juliette Becker's slides to her talk), and in fact it does not appear to be referenced anywhere else. It appears in the figures in the slides, but nothing is said about it. Assscroft (talk) 00:54, 5 June 2018 (UTC)
 * Perhaps ? In private email, Becker said "Yes, (stri)pe82 (not its identifier - just an internal name since it was found in Stripe 82 of our survey) is also hopefully forthcoming, once we recover the last few observations of it! It's not as exciting as Caju (it's pretty low inclination)." Tom Ruen (talk) 01:23, 5 June 2018 (UTC)
 * There was an additional object (ws301y4a) in one of the graphics in this guest blog by Stephanie Hamilton over at the Planetary Society blog. It may be the same object. Agmartin (talk) 16:40, 5 June 2018 (UTC)
 * Seems likely. Also here, says " 6 Nov 2017 "We have not published their elements yet, but we hope to submit a paper soon, after which we'll publish those objects" Tom Ruen (talk) 17:07, 5 June 2018 (UTC)

Another model using collective gravity
Some recent articles have been discussing a new model by Madigan, Fleisig, and Zderic (iPoster from recent AAS metting here) that use the collective gravity of many small objects to detach the orbits of larger objects like Sedna. This occurs occasionally when the orbits of a group of the objects cluster on one side of the solar system. This model explains the detachment of the objects' orbits, but not alignment, and like the inclination instability requires a sizable mass. Agmartin (talk) 17:04, 6 June 2018 (UTC)
 * How is this different from the model Madigan proposed two years ago?  Serendi pod ous  07:32, 16 June 2018 (UTC)
 * Details are scarce, it appears to be a similar mechanism but in simulations with a small number of objects. I have my doubts that it works with a larger number of objects. Agmartin (talk) 18:36, 16 June 2018 (UTC)


 * Peer-review vs no peer-review? Nergaal (talk) 08:05, 16 June 2018 (UTC)
 * So far it appears to be something interesting that occurred in their simulations that they presented at a conference, plus a press release by their university. Nothing published yet with more details. Agmartin (talk) 18:34, 16 June 2018 (UTC)

The Secular Dynamics of TNOs and Planet Nine Interactions
Paper on arxiv by Gongjie Li, Samuel Hadden, Matthew Payne, Matthew J. Holman.


 * "We find that a large number of TNOs could survive outside of mean motion resonances at 4Gyr, which differs from previous results obtained in the exact coplanar case with Neptune being treated as a quadrupole potential. In addition, secular dynamics leads to the orbital clustering seen in N-body simulations. We find that a near coplanar Planet Nine can flip TNO orbital planes, and when this happens, the geometrical longitudes of pericenter of the TNOs librate around 180∘ during the flip. Orbital precession caused by the inner giant planets can suppress the flips while keeping the longitude of pericenter librating when 30≲rp≲80 AU & a≳250 AU. This results in the alignment of the pericenter of the low inclination TNOs (i≲40∘)." Agmartin (talk) 17:25, 20 June 2018 (UTC)

Objection to term 'Planet Nine' by 35 scientists
An interesting objection to the 'insensitive' use of the term 'Planet Nine' appearing in the Planetary Exploration Newsletter and signed by 35 scientists including Alan Stern. http://planetarynews.org/archive18/pen_v12_n31_180729.txt (item 15).

Assscroft (talk) 21:42, 2 August 2018 (UTC)


 * Something of this can be added to last paragraph here: Planet_Nine. Tom Ruen (talk) 01:46, 3 August 2018 (UTC)

Planet Nine update
I received an email on July 31, 2018 (from Astronomy magazine?) stating that a team led by Mike Brown has submitted a paper announcing the discovery of (a) Planet Nine. As such things go, astronomers need to confer to assure they have their "ducks in line" before sharing details with the general public. The authors bemoaned the difficulty of having a submission peer reviewed in August. Publication will follow; the team hopes that this will occur in August 2018. At that point, the general public will have whatever details are in this paper. Assuming confirmation, an informal nickname will follow; then, eventually, an official name. Confirmation by the James Webb Space Telescope will have to wait until a few [perhaps several] months after its launch, currently slated for Spring 2021. 2602:304:B190:1550:D481:93FB:BEE8:7D1A (talk) 15:27, 3 August 2018 (UTC) Robert Gorby 2602:304:B190:1550:D481:93FB:BEE8:7D1A (talk) 15:27, 3 August 2018 (UTC) 8/3/2018 8:25 AM PDT


 * This does not seem to be true. See Talk:Planet_Nine. There's a new paper in peer review that better predicts the orbit, but not the current position. It still could be figmentary. Tom Ruen (talk) 16:24, 3 August 2018 (UTC)

The Influence of Planet 9 on the Orbits of Distant TNOs: The Case for a Low Perihelion Planet
New Paper by Jessica Cáceres and Rodney Gomes

Agmartin (talk) 20:16, 6 August 2018 (UTC)
 * In a nutshell Gomez et al proposing lower perihelion (closer to 100 AU) and same aphelion; so higher eccentricity. This reproduces the observed twin clustering of eTNOs & also Kuiper Cliff J mareeswaran (talk) 18:34, 7 August 2018 (UTC)
 * They included some analysis of what happens inside 50 AU, I wonder what happens beyond that. I expect the data from OSSOS and the number of SDOs they found in resonances will have something to say about it. Agmartin (talk) 17:58, 8 August 2018 (UTC)

Media
https://www.washingtonpost.com/national/health-science/is-there-a-mysterious-planet-nine-lurking-in-our-solar-system-beyond-neptune/2018/08/31/1957c8ca-a495-11e8-8fac-12e98c13528d_story.html — Preceding unsigned comment added by 71.197.186.255 (talk) 06:25, 3 September 2018 (UTC)

Same article also published in Quanta Magazine J mareeswaran (talk) 15:44, 3 September 2018 (UTC)


 * I didn't see anything really new there. Tom Ruen (talk) 22:33, 3 September 2018 (UTC)

Both Mike Brown and Konstantin Batygin have tweeted to refute the element of the much-copied WaPo/Quanta story that Planet Nine might be invisible being beyond 1000AU:

Assscroft (talk) 04:50, 4 September 2018 (UTC)

Batygin adds the caveat that Planet Nine can be spotted by optical telescopes, even if it is beyond 1000 AU, IF its radius is 4 times that of Earth's J mareeswaran (talk) 07:18, 4 September 2018 (UTC)
 * Is the Subaru Telescope the only telescope being used to search for it? Searching in infrared only? If not the only telescope, we should add them to the pertinent section. Thanks, Rowan Forest (talk) 17:26, 5 September 2018 (UTC)
 * It is the telescope that Brown&Batygin are using. Since they are the only team who are both able and willing to spend large amounts of observing time from a multi-meter telescope on it, Subaru is the only telescope used for the search. There's really no other telescope in the world that could compete with Suprime-Cam, anyway.Renerpho (talk) 05:14, 6 September 2018 (UTC)

Is the CMB Stage 4 referred in this article same as BICEP-3 or something else ? J mareeswaran (talk) 17:37, 4 September 2018 (UTC)
 * I looks like something different since BICEP3 is collecting data and CMB-S4 is planned for 2020 and after and at multiple sites according to its webpage, though looking at this page it might be include upgrades of existing sites. Agmartin (talk) 17:01, 5 September 2018 (UTC)

Detection using millimeter wave radiation ?
J mareeswaran (talk) 11:37, 4 July 2018 (UTC)

This table in the microwave page is very helpful in differentiating the different waves J mareeswaran (talk) 16:08, 8 September 2018 (UTC)

Planet nine workshop
Held back in May, I spotted its webpage while searching for something else. A few of the topics hint at possible upcoming papers. Agmartin (talk) 21:43, 20 August 2018 (UTC)


 * An abstract from the upcoming DPS Meeting mentions object with a = 1190 AU q = 65 AU longitude of perihelion similar to Sedna and 2012 VP113. Agmartin (talk) 21:58, 11 September 2018 (UTC)


 * I assume its here: Sednoid Tom Ruen (talk) 00:24, 12 September 2018 (UTC)
 * Probably updated semimajor axis for gna, I'd wait till there was some mention in the press before adding it to the table. Agmartin (talk) 16:13, 12 September 2018 (UTC)