Talk:Planet Nine/Archive 7

Captured from lost twin of the Sun!?
[https://www.inverse.com/science/long-lost-twin-sun-study DID THE SUN HAVE A TWIN? NEW STUDY REWRITES THE STAR'S EARLY HISTORY]

"Through his research on binary star systems, Siraj knew that these systems were much more efficient at capturing objects than lone stars. Based on that, he created a model of the Sun as part of a binary system, along with a companion star.

The stars would have been approximately 1,500 Astronomical Units apart and orbited around their shared center of mass until a passing star sort of split the binary duo and kicked out the companion, according to the study.

As a binary system, the two stars would be able to capture the number of objects in the Oort cloud, as well as a ninth, distant planet. On its own, a lone Sun would not be capable of the same.

The model increases the chances that Planet Nine was captured by a factor of 20, according to the researchers"

J mareeswaran (talk) 01:36, 24 August 2020 (UTC)
 * The actual letter. Primefac (talk) 13:45, 24 August 2020 (UTC)

ArXiv edition for ease of reading Assscroft (talk) 23:17, 27 August 2020 (UTC)

I would suggest adding a brief sentence on this to the 'Origins' section. (Now done, thanks team.) Assscroft (talk) 23:26, 27 August 2020 (UTC)

Large inclination planet
Article on arxiv last month that I missed: Mildly-Hierarchical triple dynamics and applications to the outer solar system mentions that a planet in a polar or retrograde orbit could also produce clustering of perihelion directions. But for a polar orbit objects would have higher inclinations and for retrograde orbit planet would need to be more massive, ~30 Earth mass and closer which most likely have already been observed. Agmartin (talk) 21:10, 18 September 2020 (UTC)

What if Planet 9 is a Primordial Black Hole?
Some outside the box thinking: link Agmartin (talk) 02:30, 26 September 2019 (UTC)
 * Weird. I thought black holes were massive. According to our Black hole article: "Various models predict the creation of primordial black holes ranging in size from a Planck mass to hundreds of thousands of solar masses." My head hurts.  Rowan Forest (talk) 22:27, 26 September 2019 (UTC)
 * Well they're hypothetical. So it's a stretch. Planets aren't hypothetical, so the weight of evidence points in that direction. Leitmotiv (talk) 22:42, 26 September 2019 (UTC)
 * Yes, it is way out there. I don't think we should include it in this article unless it makes waves amongst astronomers. Rowan Forest (talk) 23:39, 26 September 2019 (UTC)

I think this is fringe material. Until there's some sort of observational evidence of primordial black holes this is a theory within a theory. When you hear hoof beats, think horses not zebras (or unicorns). Mike Brown was on Twitter suggesting that P9 could also be a 5 earth mass hamburger. Jehochman Talk 01:56, 27 September 2019 (UTC)
 * It's a bird! It's an airplane! It's Russell's teapot! -Rowan Forest (talk) 04:23, 29 September 2019 (UTC)


 * It is indeed highly speculative, but it's not contrary to known physical law, would have explanatory power, is also potentially testable, and has received sufficient coverage from mainstream sources to deserve at least a mention here. It's certainly managed to get mentioned in the AAAS' Science, which is a lot more respectable than some of the sources that picked up the story. -- The Anome (talk) 08:26, 2 October 2019 (UTC)


 * This theory has no prevalence in scientific literature. This Arxiv paper is not peer reviewed as I understand. Prevalence of spectacular claims in pop culture generally does not belong in a scientific article.  P9 could be a massive alien luxury liner.  It could be any object with about 5 earth masses.  But there is no evidence it is anything but a 5 earth mass planet. 5 earth mass planets have been observed, and are in fact the only type of 5 earth mass object known to exist.  Nobody has ever claimed to have observed a 5 earth mass black hole.  Jehochman Talk 13:03, 2 October 2019 (UTC)

IF RS do not discuss it neither do we.Slatersteven (talk) 13:08, 2 October 2019 (UTC)
 * If this turns up in a published journal, where papers are reviewed by referees, then we can include it. Until then, I don't think we can.  Arxiv.org is not a published journal.  Jehochman Talk 13:13, 2 October 2019 (UTC)
 * Hence why I said what I said. At this time it is not a serious theory.Slatersteven (talk) 13:23, 2 October 2019 (UTC)
 * "Extraordinary claims require of extraordinary evidence." So I would take it a step further: publication of this hypothesis in a peer-reviewed journal is not enough, but notoriety amongst other publications that may suggest that this is indeed a significant alternative explanation. Rowan Forest (talk) 13:25, 2 October 2019 (UTC)
 * The hypothesis hasn't even been published yet. It's a SPS by relatively unknown authors.  This does not satisfy WP:RS, yet.  It might if they manage to place this in a journal. Jehochman Talk 14:19, 2 October 2019 (UTC)

Oops, apologies for whatever the last was, meant to post this cute animation: https://twitter.com/DiarybyLily/status/1180956628692025344 Agmartin (talk) 22:13, 7 October 2019 (UTC)
 * Plan(et) 9 from Outer Space! Acwilson9 (talk) 07:10, 12 February 2020 (UTC)

Looks like this subject is about to come up again: https://arxiv.org/abs/2004.14192

Another black hole article: Searching for Black Holes in the Outer Solar System with LSST
 * Given it look increasingly like there is nothing to see it not being a black hole is a likely as it not being a planet.Slatersteven (talk) 10:41, 28 May 2020 (UTC)

Spacecraft trajectories
There are now two proposals to detect Planet Nine using the trajectory of spacecraft. The first proposes the launch of hundreds of spacecraft that would send back precise timing signals so that the acceleration due to Planet Nine's gravity could be detected. The second proposes to launch a smaller number of spacecraft and to precisely measure their positions using Very Long Baseline Interferometry to detect deviations in their paths due to Planet Nine's gravity. Agmartin (talk) 03:25, 1 May 2020 (UTC)
 * That's pretty neat. Hopefully they get some funding. Primefac (talk) 16:01, 1 May 2020 (UTC)
 * Looks like it wouldn't work: https://arxiv.org/abs/2005.01120 Agmartin (talk) 00:13, 6 May 2020 (UTC)
 * Others proposed to detect its Hawking radiation from a spacecraft flyby. 02:26, 11 October 2020 (UTC)Agmartin (talk)
 * And another proposal claims a black hole could be confirmed (or ruled out within a year) by LSST detection of flares from Oort cloud comets being disrupted and accreted following close approaches. Agmartin (talk) 02:30, 11 October 2020 (UTC)

Gaseous clump
Recent paper on arxiv Orbital features of distant trans-Neptunian objects induced by giant gaseous clumps. It proposes that alignment of orbits of eTNOs is due to them being escapees from a gaseous clump on a similar orbit. This clump would have formed similarly to the gravitational fragmentation model for the formation of giant planets. It speculates that such an alignment could be maintained via the shepherding in a massive disk proposed by Antranik Sefilian and Jihad Touma. Agmartin (talk) 19:52, 17 October 2020 (UTC)
 * This appears to have been submitted to Astronomy and Astrophysics so I assume there will be some discussion of it in the press if it is accepted. Agmartin (talk) 19:54, 17 October 2020 (UTC)

Bailey?
This edit replaced "Elizabeth Bailey" with "Justin Bailey" without an explanation. Everywhere else, it is "Elizabeth", so I reverted that. I also reverted the last IP edit "Fixed typo", which was not actually a fixed typo and therefore suspicious. --Hob Gadling (talk) 07:28, 23 December 2020 (UTC)

No clustering
New paper finds No Evidence for Orbital Clustering in the Extreme Trans-Neptunian Objects. I looked at the talk archive and found a tweet mentioning this result being discussed at a conference in late 2018. Didn't know it took this long for things to get published. Agmartin (talk) 02:57, 11 February 2021 (UTC)
 * This paper is flawed. They are considering objects with q>30 which incorporates Neptune’s randomizing effects. They should be looking at objects with q large enough (q>40?) that Neptune does not perturb the objects. Jehochman Talk 15:55, 11 February 2021 (UTC)
 * Wait, they didn't account for Neptune's scattering? How many authors did that paper have, and none of them noticed that?  Serendi pod ous  16:18, 11 February 2021 (UTC)
 * They aren't stupid. The new paper is referring to the same objects as Brown and Batygin, who introduced the q>30 AU criterion in their 2016 paper, and who identify which of them are affected by Neptune. Note that none of the objects actually have a perihelion below 35 AU.Renerpho (talk) 16:26, 11 February 2021 (UTC)
 * No, Trujilo and Shephard introduced q > 30 in 2014. B&B said, .  Did the new paper do this step to ensure their selection of objects wasn't being scattered by Neptune? Jehochman Talk 16:52, 11 February 2021 (UTC)
 * The selection of objects is based on the 2016 paper. B&B used the a>150 AU, q>30 AU criterion for their initial selection of objects, so the new paper does the same. See page 8 for the analysis restricted to objects with q>40 AU. By the way, I wish we could include Figure 6 in the article! Renerpho (talk) 17:27, 11 February 2021 (UTC)
 * Wait - we can. This article and all the figures in it are published under a CC BY 4.0 license.Renerpho (talk) 17:35, 11 February 2021 (UTC)


 * In any event, I think we should include the view of this paper in the article because it's an important criticism. Jehochman Talk 17:01, 11 February 2021 (UTC)
 * This is a preprint, and should not be in the article until this passes peer-review. &#32; Headbomb {t · c · p · b} 17:30, 11 February 2021 (UTC)
 * Agmartin said "published," so I assumed it was. If it gets printed, we should include it.  Jehochman Talk 17:40, 11 February 2021 (UTC)
 * Oops, I was commenting primarily on how long ago I first heard of their combining all three surveys. There was nothing mentioned in the note on arxiv and NASA ADS hadn't been updated to include it yet. Agmartin (talk) 04:04, 12 February 2021 (UTC)
 * Agreed - let's keep an eye on it and wait till review is done. Assuming it gets published in this form, what do you think about including figure 6 from the paper in the article? Renerpho (talk) 17:43, 11 February 2021 (UTC)
 * I like figure 6. It sums up the paper.  The issue with it is whether those 14 dots are appropriate, or not, and if not, which ones should be excluded from the analysis.  If it is boiled down to 8 dots, is that enough to have a conclusive result or is the uncertainty too high? Jehochman Talk 18:29, 11 February 2021 (UTC)

Between the list of authors and abstract there is "(Received 17 October 2020; Revised 7 January 2021; Accepted 9 February 2021) Submitted to The Planetary Science Journal" So it appears to have been accepted. There is a section in our article under alternative hypotheses that already discusses temporary or coincidental clustering where a sentence could be added now. More in the opening of the article could wait until it is published and news articles with commentary from non-participants in the paper are available. Agmartin (talk) 04:34, 12 February 2021 (UTC)

Some things to note: 1) their primary analysis leaves out the 6 eTNOs used in B&B 2016, and the additional analysis include only two of those; 2) their analysis fails to reject the null hypothesis that there is no clustering based on the observations of these three surveys, it does not reject the hypothesis that there is clustering consistent with Planet Nine, which was not examined. Agmartin (talk) 04:34, 12 February 2021 (UTC)


 * Does it address why the B&B objects are co-planar? It also doesn’t address what lifted Senda’s perihelion.  This paper might weaken the evidence for Planet Nine, but I have doubts. We need to frame it properly and not over- or under-state the significance. Jehochman Talk 10:14, 12 February 2021 (UTC)
 * Question 1: Yes, it does (We find that the mean scaled longitude of perihelion and orbital poles of the detected ETNOs are consistent with a uniform population). Their argument to deal with the clustering in perihelion and orbital poles is the same, the selection bias explains both. Question 2: No, the existence of high-perihelion objects, as well as other issues allegedly solved by the Planet Nine hypothesis, remain unsolved. The paper does not claim to do miracles. It also does not prove that Planet Nine doesn't exist (such a proof isn't possible right now). It doesn't even say that Planet Nine wouldn't cause the clustering predicted by B&B. It just takes away all the evidence that such a clustering is currently detectable, which is what had made the hypothesis so appealing. For a scientific theory, removing the evidence that makes it appealing is a death blow, even if the theory isn't falsified. Renerpho (talk) 14:40, 12 February 2021 (UTC)
 * If there was some other explanation for the orbital clustering of the initial six eTNOs there wouldn't be any evidence. A bias in which discoveries get enough follow-up to prevent the eTNOs from being lost has been proposed, but I haven't seen anyone try to systematically determine if there was any. Without the clustering Planet Nine would become one of a number of explanations for Sedna and 2012 VP113, and an alternate explanation for the high inclination centaurs. Agmartin (talk) 19:09, 12 February 2021 (UTC)

Konstantin Batygin has some discussion of the article on twitter split into three threads, links to the first in each thread: https://twitter.com/kbatygin/status/1360381088216936451 https://twitter.com/kbatygin/status/1360390787653980161 https://twitter.com/kbatygin/status/1360393139463147522

Batygin and Brown also had three nights of observations at the Subaru telescope scheduled last weekend. Agmartin (talk) 02:06, 13 February 2021 (UTC)


 * The new paper does not distinguish which objects have stable or unstable orbits. Plant Nine would have the effect of causing a cluster of stable objects, and destabilizing objects outside the cluster.  Observing bias would reveal a cluster of objects that are a run-of-the-sky stable, or unstable.  B&B have identified a region that predicts stability.  When an object is in the region it's more likely to be stable.  When an object is not in the region, it's more likely to be unstable.  The inference is that gravity from some unseen object is causing this pattern of stability/instability. Observing bias cannot account for the predictive power of the B&B theory. Jehochman Talk 02:26, 13 February 2021 (UTC)
 * The predictive power of B&B's theory is uncontested. It is out of question that a massive distant planet could indeed produce clustering of orbits (and/or stable/unstable regions). The question is whether that theory is relevant to the Solar System, and more specifically, if there is observational evidence for such clustering. In my opinion, Batygin's reply is quite weak, as it does not really address the criticism (but let's see if any quotable astronomers come forward with a reply). Batygin makes it sound as if the comeback of the "P9-is-not-real-because-of-observational-bias story" was a bad thing, as if attempts to prove his theory wrong were a nuisance, or were made with ill intent. I don't like that attitude. Renerpho (talk) 17:25, 13 February 2021 (UTC)
 * Well, some of the people (a number of them being other astronomers) tweeting about the new paper did seem a bit smug about it. If there is attitude coming back, that may be why. Agmartin (talk) 18:46, 13 February 2021 (UTC)
 * Renerpho, there's a population of observed objects. Of course the place we find objects is the place where we look, so yes, there is a strong effect from observational bias.  Observational bias finds objects, regardless of whether they are stable or unstable.  What B&B have found is a region where most objects are stable, and most objects found outside that region, at similar range but in different directions, are unstable.  This asymmetry between stable/unstable cannot be explained by observational bias because observational bias does not favor one type of object over the other.  The new paper fundamentally misses this point.  Jehochman Talk 19:09, 13 February 2021 (UTC)

Some articles about the latest results from Science and Bad Astronomy and a response from Mike Brown

AKA as Planet X
I reinserted "incorrectly" to the opening sentence of the lede. Why this keeps getting deleted isn't adequately explained by the edits. It is an incorrect term. If you look above this sentence, the italic suggestion text even states "Not to be confused with the disproven Planet X". My edit synchs up with that to make it clear that Planet Nine is not Planet X. And it should stay this way. I see no reason to remove "incorrectly". It adds a lot, for so little. Ultimately, I feel Planet X shouldn't even be mentioned in the lede, but this is a compromise I'm willing to allow. Leitmotiv (talk) 23:13, 18 February 2021 (UTC)
 * But some people call it Planet X, another Planet X. That is the point. A better word instead of incorrectly might be misleadingly. -06:09, 19 February 2021 (UTC)
 * At that point you're splitting hairs. Planet X as a historical term is well established over a half century ago. It is being used incorrectly. And the phrase before the lede: "Not to be confused with the disproven Planet X" is in full agreement with me. Leitmotiv (talk) 06:30, 19 February 2021 (UTC)
 * Excuse me, but we are not here to decide whether something is used correctly or not. If there was consensus in the scientific community that those who refer to Planet Nine as a "Planet X" are doing so incorrectly then that word could stay. Otherwise this is undue on Wikipedia. I would be surprised if such a consensus existed. In fact, I have rarely ever heard anyone utter that opinion. Have you? Renerpho (talk) 09:43, 19 February 2021 (UTC)
 * You should probably read some of the old threads on the talk page to answer your question. The consensus on what Planet X is, is present on the Planet X article (also linked at the top of the page). What is Wikipedia doing misrepresenting Planet X as two separate articles? The sources on the Planet X article clearly define what Planet X is, and it is not Planet Nine. Wikipedia needs to be consistent with itself. These articles aren't isolated islands of misinformation. Just because a source erroneously refers to Planet Nine as Planet X doesn't make them an authority to blindly follow. We as wikipedians weigh the sources against each other and there is ample evidence to show Planet Nine is the preferred term, the overwhelming plurality, the correct term, and it preceded the erroneous reference as Planet X. Leitmotiv (talk) 23:37, 19 February 2021 (UTC)
 * The definition of Lowell's "Planet X" is irrelevant. If we call Planet Nine "Planet X" then it bears the same name as Lowell's planet, but that doesn't make it wrong. Planet Nine is the most commonly used term, yes, which is why this article is (correctly) named "Planet Nine". I don't argue against that. I also agree that the Planet X proposed by Lowell is a different thing entirely, which is why there is a hat note about it. However, I think we should not take sides in an ongoing debate. Some (like Mike Brown) say that "Planet X" is incorrect. Others (like Alan Stern) say that "Planet Nine" is incorrect. My personal opinion is that both sides have valid arguments, but that both statements are ultimately nonsensical and are used to push an underlying agenda (one saying there are 9 planets, one saying there are 10/X). But personal opinions don't matter here. The fact is that there are those who prefer one and those who prefer the other, each accusing the other side of being wrong. As wikipedians, we should say that there is disagreement, but we should not play judge. Renerpho (talk) 03:03, 20 February 2021 (UTC)
 * I agree with many of your points. However, the misapplication of the term probably originated from the actual Lowell's term. Since Wikipedia doesn't make the distinction, and because Wikipedia doesn't acknowledge a possible polysemy at play, it's muddying the waters. But here's the thing, I don't think Wikipedia should make a polysemy distinction, because it just convolutes the whole subject and would unnecessarily weigh down the article with useless info. Yet, without clarifying what Planet X is or isn't, this article is at odds with itself because the italic text at the top says this is not the hypothetical Planet X, only to turn around at the very start of the lede and say it is Planet X. That's why we need a clarifier. I don't care if certain folks co-opted the term from the originators. Wikipedians routinely pass judgment on articles they edit. I've participated in it, and it would be dishonest to suggest Wikipedia (and their editors) doesn't participate in weighing sources against each other when they are in conflict. This article has a conflict and is trying to have it both ways and is confusing the reader. My very simple suggestion is to have a single word in front of Planet X - one that says "incorrectly" or "erroneously" (or something to that effect). This is Brown's baby, right? We should be following his lead. It's not like I'm suggesting to do away with the Planet X term altogether, although I would enjoy that. Leitmotiv (talk) 04:48, 20 February 2021 (UTC)

Leitmotiv is right here. If Planet Nine is is referred to as Planet X, it is incorrect. It's no different than calling moons planets. You can call the Moon a planet (or a star). But it isn't one. &#32; Headbomb {t · c · p · b} 05:47, 20 February 2021 (UTC)
 * Two thing s can have the same name though. Are this places calles Paris all incorrectly called Paris? Unless someone claims this Planet 9 is the old claimed Planet X, it's misleading but not incorrect. -Koppapa (talk) 16:14, 20 February 2021 (UTC)
 * What actual astronomers call Planet Nine "Planet X"? Do you have a source for that? &#32; Headbomb {t · c · p · b} 17:22, 20 February 2021 (UTC)
 * Chad Trujillo has used the term, interchangeably with "Planet 9", when referring to the object. The name "Planet X" is also used sometimes in recent publications when the authors refer to any large distant planet, including but not limited to B&B's "Planet Nine", to emphasize that their results is about any generic, distant planet (a "Planet X") rather than some specific one (like Planet Nine). Renerpho (talk) 21:40, 20 February 2021 (UTC)
 * Mike Brown has gone out of his way to make sure Planet Nine is not known as Planet X. Now-a-days Planet X is about obsolete concepts of an undiscovered planet. -- Kheider (talk) 17:36, 20 February 2021 (UTC)
 * I concur - Planet X as a term in official context refers to a specific hypothesis which has been disproven for a long time now. Even if a professional astronomer or planetary scientist were to use the term in regards to Brown's hypothetical planet, it would be considered in error. 134340Goat (talk) 19:55, 20 February 2021 (UTC)

These people can land rovers on Mars, send a spacecraft to Arrokoth and beyond, but they can't get a name right! ;-) https://solarsystem.nasa.gov/planets/hypothetical-planet-x/in-depth/ — Preceding unsigned comment added by Messier8 (talk • contribs) 23:17, 20 February 2021 (UTC)
 * Thanks, Messier8. Maybe that's because the name isn't "wrong". I think if NASA calls it "Planet X" then that may carry some weight, don't you agree? (And that's not because NASA had any authority in the matter, it's just that they are definitely "some people".) Renerpho (talk) 02:59, 21 February 2021 (UTC)
 * Don't mistake science press for scientists. Plenty of science press gets the facts wrong. NASA appears to be no different in this regard. Leitmotiv (talk) 03:29, 21 February 2021 (UTC)
 * NASA management is biased in favor of Pluto being Planet Nine so they are not a good source. -- Kheider (talk) 16:14, 21 February 2021 (UTC)
 * NASA is biassed, yes. As are quite a few of the references cited by this article, in one way or the other (it seems like biasses are a major problem of the Planet Nine hypothesis). NASA isn't consistent, by the way: In reference Nr.172, they call it "Planet Nine". Renerpho (talk) 19:37, 21 February 2021 (UTC)
 * How do RS refer to it?Slatersteven (talk) 17:16, 21 February 2021 (UTC)
 * The majority refers to it as "Planet Nine", (that hasn't been in question, btw) but beyond that it gets murky. Of the 185 references currently cited by this article, 154 mention it in some form (the rest are either older than the hypothesis, or refer to something unrelated). Of those 154 references, 132 call it "Planet Nine" (of which 21 are published by B&B). 15 use both "Planet Nine" and "Planet X", either interchangeably,[Nr.71] or by making the distinction between B&B's "Planet Nine" and any unseen hypothetical planet (like those proposed in 2006 and 2014) as "a Planet X".[Nr.150, Nr.162, the latter of which is a publication in A&A] A few use the term "Planet Nine" in their title, but exclusively refer to it as "Planet X" after this.[like Nr.87] An additional ten sources use the term "Planet X" exclusively. Of these ten, Nr.168 is the only one that is a primary source (a published article in a scientific journal). Twelve of the sources use a completely different name, or avoid naming it at all, referring to it as "additional planet" or something similar. Of the 154 references that are relevant, a total of two make the distinction to the original 1906 "Planet X".[Nr.75 and Nr.136] I can give more comprehensive results, like a complete list of which reference uses which terms, if needed. Renerpho (talk) 19:26, 21 February 2021 (UTC)
 * No it seems to be "its incorrect", which its not as the bulk of RS use it. So we should say "or sometimes planet X".Slatersteven (talk) 09:39, 22 February 2021 (UTC)
 * Are you suggesting to keep the word "incorrect" in the sentence, or to remove it? (Excuse me, I'm not sure I understand your last comment.) Renerpho (talk) 10:10, 22 February 2021 (UTC)
 * Remove as "incorrect" is a minorty opiniuion, and is thus wp:undue.Slatersteven (talk) 11:35, 22 February 2021 (UTC)
 * Incorrect is accurate, and should stay. Planet X is Lowell's planet. &#32; Headbomb {t · c · p · b} 12:03, 22 February 2021 (UTC)

Fringe cruft in the lead
We already have a disambiguation at the start of the article that points to Planet X. I have edited that to remove "unproven," which think was a source of confusion. It is a WP:FRINGE view that Planet Nine is somehow the same as Planet X. If some unreliable source like CNET repeats this nonsense, that is of no consequence to us. It is WP:UNDUE weight to mention Planet X twice before the article even starts. If you disagree, we can discuss it and we can even have an RFC if you insist. Jehochman Talk 04:15, 6 March 2021 (UTC)
 * I reverted your edits, based on the discussion we've just had (see previous section on this talk page). We've agreed on using the word "incorrectly", but calling it WP:FRINGE goes too far. The majority of astronomers may not agree with calling it "Planet X", but there are numerous reliable sources, and a number of scientists, who use that name. None of them claims that it is the same as Lowell's "Planet X" (which would indeed be fringe). Renerpho (talk) 01:44, 7 March 2021 (UTC)

"Sometimes called Planet X by those who wish Pluto was the ninth planet" would accurately cover the 'controversy' but I suppose that would be too long. Agmartin (talk) 02:33, 9 March 2021 (UTC)
 * Maybe it would indeed be good to add that as a footnote to the first sentence. Renerpho (talk) 02:44, 9 March 2021 (UTC)
 * Definitely not. It's convoluting the lede without getting to the matter at hand. Jehochman raises a good point - Planet X is addressed in the disambiguation note. The article then repeats itself seconds later. It's not a terribly big deal, but the last thing we want to be doing is adding more about Planet X. Leitmotiv (talk) 07:07, 9 March 2021 (UTC)

I don't care about the Planet Nine vs Alan Stern/Pluto Lovers conflict. We have a disambiguation note at the top. Why the hell are we torturing this featured article by repeating ourselves excessively and redundantly to say the same thing again in the lead sentence? Do you notice how annoying and irksome it is when people waste words to fluff up their prose? Jehochman Talk 03:00, 9 March 2021 (UTC)
 * Well said! The name Planet X is, and will be, used regardless of how good, bad, correct or incorrect it is. If this object is ever discovered, neither IX nor X will be its name.Messier8 (talk) 22:59, 9 March 2021 (UTC)


 * In response to the section's creator. Maybe instead of just a disambiguation revert without “X” at the top, we include one first sentence Planet X distinction. A similar Wikipedia article correctly points out the Planet X term was NOT coined by Percival Lowell, but Gabriel Dallet and others in 1892. It is important to consider each of these astronomers used calculations that were different from the disproved prediction of Lowell, like the within “range” George Forbes in 1880 who Michael Brown noted a precursor Planet Nine theorist. Also, the beauty of “X” marks the spot in math represents an unknown number and is pronounced as a letter unlike Roman numeral 10. It was a good move to omit opinionated phrases that caused much confusion.


 * Like most users have said here, due to the diversity of both hypothetical/speculative theories surrounding not just any, but a “large” couple hundreds AU planet beyond Neptune it is an assumption to label a term even Chad Trujillo uses about the same object as WP:FRINGE. However, one is right that unreliable sources like CNET should be removed since frankly was surprised for that inclusion instead of NASA and 50 other mainstream scientific sources that use Planet X as a generic term for Planet Nine. Based on verifiable search methods, Planet X is the most popular term used for this planet and others both correctly/incorrectly. Though, I agree it is WP:UNDUE weight to mention Planet X twice before the article starts. Please see further detailed explanations with direct references in the history page. I can understand at the end of the day whether Nine or “X,” it is important to remember this is a temporary discussion. As any planet discovery, an official name will be assigned. 2601:646:9501:4120:D853:8F11:E65B:FF46 (talk) 05:50, 15 March 2021 (UTC)

Astronomy on Tap - 9/28/20
Batygin's discussion of Planet Nine begins about an hour in link He mentions some new work that includes objects in inner Oort cloud due to Sun forming in a cluster. Says Planet Nine's orbit would have to be more eccentric in that case to match observations. Agmartin (talk) 01:27, 30 September 2020 (UTC)
 * New work mentioned is now on arxiv: Injection of Inner Oort Cloud Objects Into the Distant Kuiper Belt by Planet Nine Agmartin (talk) 01:18, 14 April 2021 (UTC)
 * Twitter thread and page on their blog: The Inner Oort Cloud Connection Agmartin (talk) 01:11, 15 April 2021 (UTC)
 * A couple of on youtube discussing it: Evidence for Planet 9? A conversations with Caltech Professor Konstantin Batygin! Breaking News on the Search for Planet Nine with Dr. Konstantin Batygin Agmartin (talk) 02:18, 17 April 2021 (UTC)

Search for Planet Nine heat emissions
New article on arXiv: The Atacama Cosmology Telescope: A search for Planet 9 quote:
 * "We use Atacama Cosmology Telescope (ACT) observations at 98 GHz (2015--2019), 150 GHz (2013--2019) and 229 GHz (2017--2019) to perform a blind shift-and-stack search for Planet 9... For a 5 Earth-mass Planet 9 the detection limit varies from 325 AU to 625 AU, depending on the sky location. For a 10 Earth-mass planet the corresponding range is 425 AU to 775 AU. The search covers the whole 18,000 square degrees of the ACT survey... Overall we eliminate roughly 17% and 9% of the parameter space for a 5 and 10 Earth-mass Planet 9 respectively." Agmartin (talk) 16:37, 22 April 2021 (UTC)
 * If they find it it might be interesting.Slatersteven (talk) 16:39, 22 April 2021 (UTC)
 * More from the conclusion:
 * The upcoming Simons Observatory (SO) (SO Collaboration 2019) will substantially improve on these bounds. Extrapolating our current results to the expected depth of the combined ACT+SO data set, we can expect to detect a 5M_earth Planet 9 at 500–600 AU near the expected aphelion location and 500–900 AU over most of the rest of its orbit. This is still not enough to guarantee a discovery, but it will probe a substantial fraction of its parameter space. Agmartin (talk) 16:45, 22 April 2021 (UTC)

Neptune's distant resonances
New article on arxiv: Stability of Neptune's distant resonances in the presence of Planet Nine quote:
 * "We conclude that both resonant and non-resonant objects beyond the 12:1 near ~157 au are removed rather efficiently via perturbations from the hypothetical Planet Nine. Additionally, we uncover a population of simulated TNOs with a < 100 au, 40 < q < 45 au and low inclinations that experience episodes of resonant interactions with both Neptune and Planet Nine. Finally, we simulate the evolution of observed objects with a > 100 au and identify several TNOs that are potentially locked in n:1 resonances with Neptune; including the most distant known resonant candidates 2014 JW80 and 2014 OS394 that appear to be in the 10:1 and 11:1 resonances, respectively. Our results suggest that the detection of similar remote objects might provide a useful constraint on hypotheses invoking the existence of additional distant planets." Agmartin (talk) 22:17, 6 May 2021 (UTC)

Perihelion Gap
Potential explanation for the perihelion gap:Outer Solar System Perihelion Gap Formation Through Interactions with a Hypothetical Distant Giant Planet "Some simulations containing Planet X produce the ETNOs, the IOCs, and the perihelion gap from a simple Kuiper-Belt-like initial particle distribution over the age of the solar system. The gap forms as particles scattered to high eccentricity by Neptune are captured into secular resonances with Planet X where they cross the gap and oscillate in perihelion and eccentricity over hundreds of kiloyears. Many of these objects reach a minimum perihelia in their oscillation cycle within the IOC region increasing the mean residence time of the IOC region by a factor of approximately five over the gap region." Agmartin (talk) 01:30, 17 July 2021 (UTC)
 * Please forgive the ignorance, but in laymen's terms, is this compatible with Brown et al.'s Planet Nine hypothesis, or does this suggest a different possible cause for the unexplained configuration of ETNOs? 134340Goat (talk) 03:11, 17 July 2021 (UTC)
 * What they are saying is that under Planet Nine's influence some of the objects that start with perihelion near Neptune's orbit don't return to that orbit. Instead their perihelion goes through a cycle that has a minimum at 65 au or higher. Agmartin (talk) 23:45, 18 July 2021 (UTC)
 * Sounds like 90377 Sedna. Jehochman Talk 20:03, 19 July 2021 (UTC)

New paper from Brown & Batygin
Brown and Batygin have published a new paper which addresses some of the observability bias arguments advanced earlier this year. This is still very recent but it's probably worth keeping an eye on the astronomy press in the coming weeks and months as I expect there will be quality material to work into the article. Eniagrom (talk) 02:06, 26 August 2021 (UTC)


 * Appreciate the update! If the new estimate of semi-major axis for Planet Nine is 380 AU (440 limit), what will its orbit be 10,000 or less in years? Thanks in advance.~ — Preceding unsigned comment added by 2601:646:9501:4120:DD4C:AFF:A56A:7D10 (talk) 04:37, 27 August 2021 (UTC)
 * It's better off taking questions like that to another place like Reddit or something - Wikipedia talk pages are intended to discuss the article itself - but to briefly answer your question, it depends on a number of variables, but with the given data, its orbital period could fall in the range of roughly 5200-11,800 years. Give it some patience. If the planet exists, Brown and Batygin estimate we'll probably know at least a bit more about it before the end of the decade 134340Goat (talk) 20:26, 27 August 2021 (UTC)
 * Great answer as I hoped from my question one can infer the need to include its updated orbit in years inside said infobox. This way general readers will better understand what AU means time wise.134.79.160.199 (talk) 06:20, 1 September 2021 (UTC)

With this new paper, the "Updated model" section is now ironically outdated and presents older information than the infobox at the top. Should the most recent numbers be reflected there, or would we be better off just removing that section altogether? 134340Goat (talk) 20:46, 27 August 2021 (UTC)


 * Update to match the latest published research. The key word is "published."  This is still a pre-print.  Should we hold the horses a bit longer?  Jehochman Talk 21:07, 27 August 2021 (UTC)
 * Eh, I mean, the infobox is already updated and the arxiv is sourced. One way or another, it's information that will be published soon. I think it's more efficient just to consider that the latest information, even if it's not officially published. 134340Goat (talk) 21:54, 27 August 2021 (UTC)
 * Hi, wouldn't it make more sens to update "Orbit" and "Mass and radius" rather than to create an "Updated model" section? Maybe there could be an explaination that the model was updated in 2021 in the "History" section? I found at least one National Geographic article on the subject that could be used to make these changes. I also find the way the plus-minus sign is written confusing to the casual reader. Giving a range would be more practical. - Espandero (talk) 19:21, 6 October 2021 (UTC)

Preprint for potential candidate
I removed the following paragraph as sourced only to arxiv:

Posting it here so that it can be re-added when the research is published. Primefac (talk) 08:29, 9 November 2021 (UTC)
 * Wikipedia inclusion policy on non-obvious topic explicitly require to provide reference, not peer review. Normal practice for papers which fails to be peer reviewed is to just mention the presense or absense of peer review, not to delete data outright.Trurle (talk) 08:53, 9 November 2021 (UTC)
 * See this discussion, a bit in this discussion (let's keep an eye on it and wait till review is done), among others, as to why we tend to not use preprints.
 * Also, as a minor point regarding BRD (mentioned here), it's "BOLD, revert, discuss", not "BOLD, then revert until they agree with you on the talk page". I disagreed with your change and started a discussion, so you're the one that needs to convince folk to keep the content. Primefac (talk) 09:05, 9 November 2021 (UTC)
 * "Bold, revert, discuss" is neither recommended nor obligatory on any page. Appropriate is Consensus. Primefac have made an error here trying to remove a significant primary reference from Wikipedia. Potentially high-impact data should be properly presented, not silenced. Regarding Talk:Planet_Nine/Archive_7 the Primefac is trying to promote as exemplary discussion, i strongly disagree. The discussion mentioned is of very poor quality by scientific or even Wikipedia standards, including a mockery and authoritarian arguments violating WP:NPOV. Trurle (talk) 09:36, 9 November 2021 (UTC)
 * Well, clearly we disagree, so I'll wait for others to comment. Primefac (talk) 09:59, 9 November 2021 (UTC)
 * It does point out that it has been accepted for publication in MNRAS, however one would think that extraordinary claims require extraordinary evidence. and that if this were a distinct possibilty then maybe Mike Brown would be talking about it on twitter or something....in two minds here but leaning on leaving it out for the moment.Cas Liber (talk · contribs) 10:37, 9 November 2021 (UTC)
 * There is is not much peer-review when a paper is authored by one guy. I say leave it out until more information is available. -- Kheider (talk) 11:27, 9 November 2021 (UTC)
 * Can someone explain to a nonscientist that a source which says (in the summary) "I have examined the unidentified sources in three IRAS 60micron catalogues: some can be identified with 2MASS galaxies, Galactic sources or as cirrus. The remaining unidentified sources have been examined with the IRSA Scanpi tool to check for the signature missing HCONs, and for association with IRAS Reject File single HCONs. No matches of interest survive." is not saying "I have not found a planet"?Slatersteven (talk) 11:19, 9 November 2021 (UTC)
 * Not detected on short distances (fast movers). Later in text the different criteria for long distances (i.e. slow-moving targets) have resulted in claimed detection.Trurle (talk) 11:33, 9 November 2021 (UTC)
 * Then we might be able to say that "According to Michael Rowan-Robinson his search of IRAS data found a faint match". But then we have the issue of but is this really a significant opinion. It is one many in (what appears to be) an un peer-reviewed paper. After years of no one finding anything I think we need a lot better than a faint match.Slatersteven (talk) 11:38, 9 November 2021 (UTC)
 * I do not know if the author opinion is significant or not. But it at least verifyable - and much more easily than vast majority of planet Nine related peer-reviewed modeling and speculations. The basic scientific criteria is verifiability, not authoritative opinion (glorified as peer review) after all.Trurle (talk) 12:15, 9 November 2021 (UTC)
 * Is that the case, as far as I was aware the criteria is "is it an RS" (it passes that as he is an expert). Then "Is it a fringe view" (I am unsure it passes that as it is just his view).Slatersteven (talk) 16:08, 9 November 2021 (UTC)


 * As a featured article, it was promoted on the premise that claims are verifiable against high-quality reliable sources. I suggest that by their nature this precludes pre-prints. Also per NOTNEWS and NODEADLINE, what's the rush. ——  Serial  11:27, 9 November 2021 (UTC)


 * Argument by ——  is sadly illustrating the sort of harm done by rating articles. Yes, the rating satisfy the desire of some editors to keep things neat and clean. In expense of others aspects.Trurle (talk) 11:51, 9 November 2021 (UTC)
 * No, the consensus is regardless of rating. Most posters on this page are not concerned with the article's rating. Anyway, Mike Brown is talking about it on twitter now so is getting traction. Cas Liber (talk · contribs) 12:11, 9 November 2021 (UTC)
 * Citing twitter of Michael E. Brown.
 * The candidate is on an orbit utterly inconsistent with our predictions for Planet Nine, and would not be capable of gravitationally perturbing the distant solar system in the ways that we have suggested. But, of course, that doesn't mean it isn't real!     Interesting...good fast answer for one of questions of original paper.Trurle (talk) 12:20, 9 November 2021 (UTC)

Forgive me if my memory is mistaken, but did we not integrate the new data from Brown and Batygin's 2021 arxiv on here before further publication when we discussed that two sections up from here? I don't see why this couldn't go on here - but as a related or alternative hypothesis (since according to Brown's Twitter, while this might be something that exists, it certainly is not the hypothetical planet he and Batygin have envisioned, and if a ~4 Earth-mass planet really is found a couple hundred AU out there, it would be through pure chance) 134340Goat (talk) 16:35, 9 November 2021 (UTC)
 * according to Brown's Twitter - Just a note: We don't need to refer to Twitter and/or Mike Brown here. The paper itself says the same. Renerpho (talk) 17:47, 9 November 2021 (UTC)

I think it's good idea to include it since the author Michael Rowan-Robinson seems to be a subject-matter expert, as per WP:RSP. ExoEditor 16:57, 9 November 2021 (UTC)

I suggest to wait. What do we even want to include? Regarding the validity of the claim, the author themselves states that the detections are not of high quality, do not show a strong correlation with a point-source profil, and that the source was in a region strongly affected by cirrus - in other words, it is regarded as "unlikely to be real" even by the author. It is also definitely not the Planet 9 predicted by Brown&Batygin. Considering this, the detection part of the paper seems of little interest for this Wikipedia article. This would change if it actually leads to the serendipitous discovery of another planet, but we're not there yet. More interesting for the Planet 9 case is the part about constraints put on Planet 9 by its non-detection (see the "Discussion" section). This is worth adding once it has been peer-reviewed. In the mean time, the only people who that paper should concern are the astronomers capable of checking if it's correct (and searching the proposed region of the sky). We don't need Wikipedia for that, and Wikipedia doesn't need to be concerned about that process. Renerpho (talk) 17:41, 9 November 2021 (UTC)

I concur with waiting. IRAS isn't exactly a cutting edge instrument, and it has a history of false positives when planets are concerned.  Serendi pod ous  18:47, 9 November 2021 (UTC)


 * Wait. Somebody may have found a potential unknown solar system object, or more likely a false positive, that does not fit the predicted profile of Planet Nine. This finding is interesting but not yet established to be related to the Planet Nine hypothesis. Jehochman Talk 20:40, 9 November 2021 (UTC)

Regardless, however, if a ~4 Earth mass object has been discovered, would it not be worth mentioning on this page, even if it is not P9, as it would have been found (again, if real) during a search specifically for Brown and Batygin's P9? 134340Goat (talk) 05:30, 10 November 2021 (UTC)
 * Sure, if a new planet gets discovered, it will likely get its own article (and likely a mention here as well). However, that has not happened, so "man potentially finds something" is all we have right now. Primefac (talk) 07:23, 10 November 2021 (UTC)
 * If is not Has, when they find it we can mention it.Slatersteven (talk) 09:55, 10 November 2021 (UTC)
 * This would be relevant if this planet existing would be evidence that Planet Nine does not. For example, if interactions between the two would lead to one or both being ejected. While that seems likely to me, I have seen no authoritative claims either way. Agmartin (talk) 18:48, 11 November 2021 (UTC)
 * Interesting point, Agmartin. From my experience, the theoretical papers regarding its effects on Planet 9 won't be far behind if this new prediction is considered credible. We'll see if someone jumps on the wagon. Such a paper, once published, could turn the existence of the small predicted planet into a testable prediction of the Planet 9 hypothesis (as in, Planet 9 implies that the small planet doesn't exist), which would be very relevant indeed, even before the small planet is actually found (or ruled out). Renerpho (talk) 01:25, 12 November 2021 (UTC)
 * Are you aware of any "uniqueness results" regarding Planet 9? Constraints on the existence of any additional planets (aside of Planet 9) that would be allowed while keeping the rest of the Planet 9 hypothesis intact? This new paper is not the first result that claims planets that are "competing" with Planet 9; the two planets predicted by the de la Fuente Marcos brothers come to mind. Have there been any studies that look into what kind of additional planets could still exist alongside Planet 9? Renerpho (talk) 01:33, 12 November 2021 (UTC)
 * I might be misunderstanding your question, but per Brown and Batygin, it's also possible that instead of one single, high mass planet, it could be two or three planets that cumulatively add up to that mass, or a large population of smaller objects whose gravity would effect the orbits of the eTNOs which led to the theory in the first place. As for whether this potential object could play into it or not, I suppose time will tell. My money's just on this being a false positive (though that could just be wishful thinking since I think a 5 or 6 Earth mass planet would be a lot more interesting lol) 134340Goat (talk) 05:36, 12 November 2021 (UTC)
 * Not related to your question, but there is Planet 10 which currently links to Planets beyond Neptune. IIRC, it would be a Mars-sized planet. Leitmotiv (talk) 17:41, 12 November 2021 (UTC)