Talk:HR 8799

4th Planet
Pls add reference to the 4th planet detected, as published in Nature December 8, 2010 by Marois et al. Note too the existence of this planet defies present understanding of planet formation. Tony (talk) 15:02, 9 December 2010 (UTC)
 * There's already a ref to preprint. BlueEarth (talk | contribs) 21:23, 9 December 2010 (UTC)

Orphaned!?
This page shouldn't be orphaned. There should at least be a link via exo-planets (stars with exo-planets).--210.248.139.34 (talk) 02:11, 14 November 2008 (UTC)


 * It is. I'm removing the tag. kwami (talk) 03:03, 14 November 2008 (UTC)


 * Thank you! I loves me my extra-solar planets.--210.248.139.34 (talk) 05:40, 17 November 2008 (UTC)

Distance
Typing "HR 8799" "light years" into Google gives either 128 light years, 129 light years, 130 light years or 140 light years. The press release says 140 light years. Could someone confirm an accurate value ? Delaszk (talk) 10:18, 14 November 2008 (UTC)
 * The discovery paper cites the van Leeuwen (2007) reduction of the Hipparcos data for the distance, a catalogue which is available on CDS as I/311. One of the features in the starbox template used in this article is automatic calculation of distances from the trigonometric parallax, so provided the correct parallax and parallax error is put into the template, the correct distance will be displayed. I have also verified the calculation independently of the templates, and the figure of 129 light years is correct. The discovery paper appears to have a rounding error in the parsecs to light years conversion: the value is rounded down despite the fractional part being more than .5, hence the figure of 128 that's floating around. 130 light years is the value from the original reduction of the Hipparcos data (ESA 1997). Not sure where the 140 light years value is from. Icalanise (talk) 10:37, 14 November 2008 (UTC)
 * Thankyou. I guess 140 was just a typo. Delaszk (talk) 15:18, 14 November 2008 (UTC)
 * Convergent rounding? (128 vs 129) -- BohemianWikipedian  talk 21:52, 14 November 2008 (UTC)

2nd, 3rd detection?
Given the unconfirmed nature of 1RXS J160929.1-210524b and the high mass ratio of the 2M1207 system (plus various other directly-observed objects near the brown dwarf/planet borderline, look up CHXR 73B and DH Tau B for example), it's going to be somewhat controversial about whether this is the 1st, 2nd, 3rd, etc. direct detection of an extrasolar planet, so I've removed the statement about the HR 8799 planets being the 2nd detection in the infrared. On the other hand, it is definitely the first multi-planet direct detection. Icalanise (talk) 19:30, 16 November 2008 (UTC)

useless?
Appears to me worth mentioning how extremely useless this solar, stellar system is. It actually suggest young systems are instable,and a record dust ring would mean record impacts. What I would like to see cleared up is wether the stars curious fluctuations (and dust ring) are a common or rare feature of young stars. Because now I really wonder. The iron depletion is interesting, but isn't that reference obscure without at least a hint of the systems surrounding? It's not that the educational aspect is divertion, a formal "The designation HR 8799 is the star's identifier in the Bright Star Catalogue." shows? 80.57.67.243 (talk) 06:54, 17 November 2008 (UTC)


 * One could argue that all star systems beyond our own are extremely useless because right now there is no way to get to any of them. I agree that there isn't much context for most of the stuff in the lede paragraph: it turns out that HR 8799 is an interesting star for far more reasons than merely by having planets. Most of the lede paragraph of this article needs expansion. Icalanise (talk) 11:20, 17 November 2008 (UTC)


 * There's no rule WP:USEFUL, and besides I disagree, because I can easily use the system (and the article) for wild speculations. Rursus dixit. ( m bork3 !) 20:08, 5 July 2010 (UTC)

It still can't be ruled out that there aren't any Earth-like exoplanets that we simply can't detect. If there were any detected I wouldn't argue this system is useless. This system also seems to be useful because we can study the planets simultaneously which is powerful given their connected formation histories and appearances.Jagon22 (talk) 22:43, 23 March 2012 (UTC)


 * Yes it's probably useless to a person on the street with no interest in stellar astronomy. Otherwise it's an interesting star, regardless of whether it has a planetary system. Regards, RJH (talk) 00:55, 24 March 2012 (UTC)

Debris Disk Pics
Added debris disk pics and description. I only have access to the Abstract so if someone else has access to the full publication doi:10.1088/0004-637X/705/1/314 If someone has access to the entire paper, perhaps more detailed info. can be added in keeping with the details reported on the rest of the page. Canuck100 (talk) 07:58, 9 November 2009 (UTC)

New Pictures
There are some new direct images of the planets in the system in the H band and at 3.3 micrometers. They might be worth adding to the page. The pictures were taken with the Large Binocular Telescope and their First Light Adaptive Optics (FLAO) system. Here's the archive link: http://arxiv.org/abs/1203.2615.Jagon22 (talk) 22:37, 23 March 2012 (UTC)

External links modified
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A Commons file used on this page has been nominated for speedy deletion
The following Wikimedia Commons file used on this page has been nominated for speedy deletion: You can see the reason for deletion at the file description page linked above. —Community Tech bot (talk) 05:07, 12 February 2019 (UTC)
 * ExoplanetarySystemHR8799-20181121.jpg

Deep orbital search for additional planets in the HR 8799 system
I see a new paper is here that refines knowledge on this system. Tom Ruen (talk) 11:15, 23 December 2022 (UTC)