Talk:Gliese 581e

Signal Detection

Whoever put this section in, it is inaccurate, the 'laser-like' signal was not detected near Gliese 581e, the planet was merely mentioned in the same article. The astrophysicist has not yet announced where the source of the alleged signal is coming from. I am therefore removing this section.75.67.80.68 (talk) 22:38, 20 May 2009 (UTC)

Agreed. If it reappears, it should be deleted. — Aldaron • T/C 22:43, 20 May 2009 (UTC)

Agreed.--84.122.154.39 (talk) 18:00, 23 May 2009 (UTC)

You are right. Sorry for reverting your removal, I didn't notice this explanation first. Offliner (talk) 18:43, 23 May 2009 (UTC)

COROT-7b "previous smallest"?

I've deleted the unsourced section on COROT-7b as the "previous smallest planet discovered". While COROT-7b had (and still has) the smallest known radius, it did not have the smallest reported mass (see HD 181433 b, for example). — Aldaron • T/C 15:48, 23 April 2009 (UTC)

81.155.8.127, please discuss your edits here. Reverting a disputed edit already marked as unsoruced (by a third party) is discouraged. — Aldaron • T/C 16:34, 23 April 2009 (UTC)

Protect page?

Can some admin protect the article, it is under constant attack Mtpaley (talk) 17:32, 23 April 2009 (UTC)

"Discovery site"?

Not sure if there is a better place to raise this, but here it goes: Does the info box really need the country as the discovery site? I think it would be better to record the Observatory (name? location?) - Instrument combination. This would be way more informative than a country! Awolf002 (talk) 20:23, 23 April 2009 (UTC)

Good question! I asked how the discovery site parameter is supposed to be used at Wikipedia talk:WikiProject Astronomical objects. Meanwhile, the current entry is wrong: it was not discovered in Switzerland. I changed it to the observatory. Finell (Talk) 22:10, 23 April 2009 (UTC)

Yes, the documentation for the template says discovery site is the observatory. — Aldaron • T/C 19:41, 27 July 2009 (UTC)

Run-on sentence

If I get some time this weekend I'll take a stab at breaking up this sentence into something a little more manageable:

"At a minimum of 1.9 Earth masses, it is the smallest extrasolar planet discovered around a normal star, as of 23 April 2009, and the closest in mass to Earth, though at an orbital distance of just 0.03 AU from its parent star (which is well out of the habitable zone) it is unlikely to possess an atmosphere due to its high temperature, small size, and strong radiation from the star." Wolfhound668 (talk) 20:38, 24 April 2009 (UTC)

I've made start. I think the first step is to delete the mention of date. — Aldaron • T/C 21:00, 24 April 2009 (UTC)

Good start. The date was definitely bothering me, although I'm guilty of overusing parenthesis myself. I've tried to break it up into three separate sentences. What do you think? Wolfhound668 (talk) 21:28, 26 April 2009 (UTC)

Much better. The causal link in the last sentence bothers be a bit though; what's the "this" being referred to? If it's the exclusion from the habitable zone, for example, then being "due to" small size doesn't work (esp. since that "small" size is minimally twice the size of a famously atmosphered planet). I've tried an alternative to deal with this, but it still needs fixing. — Aldaron • T/C 21:39, 26 April 2009 (UTC)

I like this version. Concise, easy to read, and I think it gets the point across. Wolfhound668 (talk) 01:14, 27 April 2009 (UTC)

Alternate exoplanet designations in main text?

76.66.196.218, no need to shout. This is a general issue that should be discussed in the appropriate place. — Aldaron • T/C 16:22, 26 April 2009 (UTC)

I was reemphasizing my edit that added it, while your edit removing it provided an unreasonable example. 76.66.196.218 (talk) 01:28, 27 April 2009 (UTC)

Let's keep this discussion in one place. — Aldaron • T/C 03:40, 27 April 2009 (UTC)

This picture is nonsense by the publishers description... now RFC

description

• Delete - There are supposed to be 4 planets lined up in the picture (file name says photo) and the blue dot that looks like a moon of the so-called farthest planet out is supposed to be one of those 4 planets. Just because someone contributed their picture to an official site for a judging contest doesn't mean it is an official picture, it's still trash. GabrielVelasquez (talk) 00:42, 10 July 2009 (UTC)

OK, I didn't realize there was a discussion on here (please forgive me). I see nothing wrong with this particular image. Can you explain to me what you find "nonsensical" about this image? — NuclearVacuum 16:11, 14 July 2009 (UTC)

• Keep - Scientifically, this image is correct. The four planets are indeed in this image. The "blue moon" (as you call it) is indeed one of those planets (planet b to be precise). The two planet orbit close to each other, that you would be able to clearly see planet b from planet e, while planets c and d would appear as bright stars (similar to how we can see the the planets of the solar system in our sky). In my personal opinion, the only thing that makes this image nonsense is that it is a speculative artist's image. But since we do not know what these planets actually look like, we don't have an image of them as a spec (like we do with Fomalhaut b), and it is likely we will not be able to actually view these planets in detail for several centuries (if not millenniums), an artist's image is just as good. — NuclearVacuum 16:11, 14 July 2009 (UTC)

• Keep - like user:NuclearVacuum, I'm mystified by what the supposed problem is. Are there four planets depicted or three? Well, who cares? What does it matter? It's a sourced artist's impression of the planet covered in this article. That it also depicts some space, some stars, and some other planetary bodies is irrelevant; that it fails (or may fail) to depict some other space, some other stars, some other planetary bodies, or even the '38 Yankees, is likewise quite simply irrelevant.- Simon Dodd { U·T·C·WP:LAW } 15:19, 23 July 2009 (UTC)

• Keep - I also don't see what the problem is with the picture. It's an artist's rendition. Wolfhound668 (talk) 14:51, 27 July 2009 (UTC)

• Delete - The description presents an impossible scenario and has to be wrong. As I've said elsewhere, I don't see the issue in general with artists impressions (even quite fanciful ones) as long as their descriptions provide suitable explanations of the speculative nature of what's being depicted. I would argue that use of images supplied by official organizations associated with a discovery is fine, and should in fact, be encouraged (since for most of these planets they are the best impressions we will have for quite some time) as long at is made clear that the image represents an artist's impression of one possible form of the planet. However, in cases like this one, were the source's image description is in error, we should not use the image. — Aldaron • T/C 15:15, 27 July 2009 (UTC)

• Delete - The image cannot be a view from planet e as the phase shown of the blue planet is impossible, unless the blue planet is located closer to the star than the foreground planet. Maximum phase angle occurs when the planet and star are in quadrature, and thus for planet b as viewed from e, it cannot exceed ~45-50 degrees, which corresponds to a gibbous phase, while the blue planet is depicted at half phase. The image therefore is inconsistent with basic principles of lighting. Icalanise (talk) 19:01, 28 July 2009 (UTC)

Wow, your right. The description makes no sense at all. I think it has to be in error. I'd still keep it for the time being, but make clear (on the image's Wikimedia page) that the description provided by the source has to be wrong. Vote changed. — Aldaron • T/C 19:47, 28 July 2009 (UTC)

In other words, the artist took some artistic license with the small details, or didn't understand the mechanics of such fine-grained details. Again: so what? Are we supposed to delete File:Planets2008.jpg on the grounds that the image depicted is impossible and inconsistent with basic principles of lighting? That absurd result is the upshot of your argument. This file doesn't purport to be a photograph; it's an artist's impression. It may be a problematic representation of the system, but it's a well-sourced artist's impression of the subject of this article, and it serves the reader just as does File:Planets2008.jpg. Your argument might justify excluding the picture from an article dealing with the system in toto, although I would still resist that conclusion, but not from this article. - Simon Dodd { U·T·C·WP:LAW } 14:08, 29 July 2009 (UTC)

The issue is with the description. As I argue above, there's nothing wrong with artist's impressions, and their inclusion should in fact be encouraged (even fanciful or speculative ones, as long as those aspects are made clear). The issue here is that the description accompanying this illustration is frankly in error (and thus confusing to readers) and leaves us doing original research as we struggle to interpret it. I encourage anyone who originally voted (as I did) to "keep" to review the configuration of the Gliese 581 system. You'll see immediately that the description is nonsense. — Aldaron • T/C 17:17, 29 July 2009 (UTC)

To explain what should be an obvious point, File:Planets2008.jpg is a diagram, while File:Phot-15a-09-fullres.jpg is meant to be a view from within the system. There is no real comparison between the two. Icalanise (talk) 17:37, 29 July 2009 (UTC)

The issues raised by Icalanise are with the depiction of Gliese 581 b and Gliese 581 d, and the issue that you raise is with the depiction of the other planets as orbiting between Gliese 581 e and the star (i.e. the planets are depicted in reverse order to their actual orbits). But this is the article on Gliese 581 e. Is there a problem with the representation of Gliese 581 e?

I don't see error in the description, let alone nonsense. It's the image itself that is, in some respects, nonsense - if one assumes that it is supposed to be the equivalent of a photograph, representing the actual configuration of the system. By that standard, however, so is File:Planets2008.jpg.

It seems to me that the real argument to inclusion vs. exclusion is over how we should answer the following question. Is any benefit to the reader in seeing what Gliese 581 e may look like outweighed by any detriment to the reader in the risk of their thinking that the image represents the actual configuration of the system, an impression that could arise from other things depicted in the image? I agree that this is an imperfect image, marred by artistic license or misunderstanding. When a better image becomes available, we should use that one. But for now, I believe this is better than nothing.- Simon Dodd { U·T·C·WP:LAW } 17:55, 29 July 2009 (UTC)

Given the image includes lens flare, clearly includes perspective and appears to be an attempt to visualise what it would be like in the Gliese 581 system, I think yes it is intended to be the equivalent of a photograph. File:Planets2008.jpg makes no attempt at perspective or positioning, but functions as a radius comparison and gives the objects in order of increasing solar distance (though the distances depicted are not to scale) and clearly makes no attempt to be the equivalent of a photograph whatsoever. Icalanise (talk) 18:20, 29 July 2009 (UTC)

I agree completely with your formulation of the question. I would just argue that since the description does in fact suggest that the image "represents the actual configuration of the system", the risk is high. (There must be some general policy that's applicable here: what do do if there's a reasonable case for including an image on its own merits, but the description of the image at its source is in error or confusing. If there is, we should just apply that.) — Aldaron • T/C 18:24, 29 July 2009 (UTC)

I'm a little vague on our image policy, but if I'm not mistaken, for an image to be included here, it has to be by-and-large free of restrictions. If this one is here on a license that allows us to do so, why don't I just pull the image into photoshop, delete the other three planets, and we'll use that image? - Simon Dodd { U·T·C·WP:LAW } 18:54, 29 July 2009 (UTC)

Well here's ESO's page on the matter of copyright and licensing. Icalanise (talk) 18:59, 29 July 2009 (UTC)

(undent) Done

The original was released under a cc3 license that allows adaptation. I have adapted the file by airbrushing out the three planets that users have said cause the problems (the orbital distance implicit in the perspective is unfixable but not particularly troubling.)- Simon Dodd { U·T·C·WP:LAW } 19:06, 29 July 2009 (UTC)

While I am definitely opposed to the image with the other planets as being an impossible representation, I am more neutral to this new version. Note you should probably explicitly state that the original image was from ESO in the summary - I know this is implied by the link but stating it in the text itself cannot hurt. Icalanise (talk) 19:20, 29 July 2009 (UTC)

Shouldn't we just delete this image altogether? There's nothing encyclopedic (and a lot that's misleading or just fanciful) about this (and most "impression") images. — Aldaron • T/C 13:03, 6 October 2010 (UTC)

Distance

The Gliese star page says it's 20.3LY away this page says 20.5LY which is it? —Preceding unsigned comment added by 67.204.24.19 (talk) 11:33, 21 June 2010 (UTC)

Size estimate?

Is there a size (i.e. diameter/radius) estimate for this planet? Since it is the lightest non-pulsar exoplanet known, I'd expect it to be the smallest as well (i.e. smaller than Kepler-10b's 1.4 Earth radii). --Roentgenium111 (talk) 17:40, 11 January 2011 (UTC)

No. It's not transiting, so any such size estimate would have to be based on compositional models, which would produce a wide range of values. In addition, since the inclination is unknown, the mass itself is a (minimum) estimate. — Aldaron • T/C 17:57, 11 January 2011 (UTC)

There is an upper limit for 581 e's mass of 3.1 Earth masses as well (see Gliese_581#4-planet_solution_(2009)), if the Gliese 581 system is to be stable, which is still smaller than Kepler-10b's mass. So could its composition be such that it turns out to be bigger than Kepler-10b, and is this likely? If so, we should correct the "smallest exoplanet" claim in this article.--Roentgenium111 (talk) 18:35, 11 January 2011 (UTC)

Yes, it could be still be bigger. It's hard to know how likely that is though without knowing more (and having more published). — Aldaron • T/C 18:41, 11 January 2011 (UTC)

Iv'e added an image that compares some modeled sizes based on the minimum mass. The figure's caption explains some of the limitations of these models. — Aldaron • T/C 18:38, 11 January 2011 (UTC)

Thanks for the interesting image. But is a "water planet" possible so far inside the habitable zone? I'd think not - all the water would be in vapor form and soon be lost to the solar (stellar?) wind. --Roentgenium111 (talk) 15:02, 30 March 2011 (UTC)