# Talk:Upsilon Andromedae d

After review, I've determined that this article meets the qualifications for GA status. It is well written, well referenced, and comprehensive. I'm "Mass Passing" this article along with 9 others. The entire list is below. If new developments arise that would effect the references or comprehensiveness of this article, it may affect the others as well.

55 Cancri b
55 Cancri c
55 Cancri d
55 Cancri e
16 Cygni
16 Cygni Bb
Upsilon Andromedae
Upsilon Andromedae b
Upsilon Andromedae c
Upsilon Andromedae d
Keep up the good work. These articles are ideal "good articles". They can't be FA, because there is no way for them to get long enough, but they are as comprehensive and complete as possible, and represent a good effort on the part of the editors. Feel free to message me if you have any questions about my rationale. Phidauex 18:18, 14 July 2006 (UTC)

It says a Mars size Moon is approx the upper limit for a Jupiter mass planet, this planet is near 4 times jupiter mass, is citation 8 and its corresponding sentence really applicable? -- Nbound 12:29, 12 September 2006 (UTC)

Well, it also states that within the regime of the solar system, the mass fraction of the satellites over the range of gas giants is pretty similar, so it may also apply to extrasolar planets of more than a Jupiter mass. If the sentence stated explicitly that large moons would definitely not form, then I'd agree. However, in the context of a discussion about habitable moons I think the reference is useful. Maybe it might be good to expand the point a bit (though not so much that we swamp the section!), I will agree the sentence as it stands just chucks the reference in there in a rather unexplained way. Chaos syndrome 19:29, 12 September 2006 (UTC)
I actually removed this claim; the reference is undobutably interesting, but it doesnt seem to have any relevance to this article. As you say, the mass FRACTION of the satellite over the range of gas giants is pretty similar, i.e. that means the reference is clear in stating its in proportion to the mass of the primary planet. But I removed it because the reference states "suggest that similar processes could limit the largest moons of extrasolar Jupiter-mass planets to Moon-to-Mars size." Note it says Jupiter-mass. The citation given here says simply omits the Jupiter-mass part. With a 4 times as massive a planet as Jupiter, you get something like half-an-earth mass moon this way (scaling mars-size; this is similar to ratio of the mass of titan and saturn). it states its ~10^4, clearly with quite a variance (Moon - Mars is an order of magnitude difference). With 4*300/10^4= 0.12 (litle over Mars size) as average, and given the order of magnitude variation implied, thats 0.6-0.024. I dont wish to be rude, but you do understand the concept of fraction, right? Its hard to see this from the sentence "the mass fraction of the satellites over the range of gas giants is pretty similar, so it may also apply to extrasolar planets of more than a Jupiter mass." and the conclusions you seem to draw from it.
More importantly this reference http://www.nature.com/nature/journal/v385/n6613/abs/385234a0.html says little over Mars-size (more precisely, 0.12 of earth mass) is sufficient anyways, so theres little point in discussing the size of the moons in this section at all.  --89.172.84.10 11:48, 31 May 2007 (UTC)
If you didn't mean to be rude, you could have dropped (or at least rephrased) your comment, which was completely unnecessary to your argument. Evidently that was not your aim, so don't increase the insult by pretending otherwise.
Maybe I was being unclear about my reasons for including that statement in the article: my general feeling is that the possibility of formation of habitably-large moons around jovian or superjovian planets is unknown at the current time (since our total sample size of exomoons is zero, and the total sample size of moons of Mars-mass or above in our solar system is also zero), and there are mechanisms which suggest upper limits on moon masses through certain mechanisms (moon migration and eventual accretion onto the parent planet). Whether the numerical relationship between planet and satellite system found for jovian-mass planets holds in the superjovian regime, the paper doesn't indicate. Note also that the jovian system, while higher mass than the Saturnian one, has the mass distributed among multiple satellites, so even if the satellite system of a superjovian has Mars mass, it might be distributed between many Moon-sized objects. I was just attempting to point out that habitable moon formation is by no means a proven possibility. Chaos syndrome 23:10, 15 July 2007 (UTC)

As part of the WikiProject Good Articles, we're doing sweeps to go over all of the current GAs and see if they still meet the GA criteria. I'm specifically going over all of the "Planets and Moons" articles. I believe the article currently meets the criteria and should remain listed as a Good article. I have made several minor corrections throughout the article. Altogether the article is well-written and is still in great shape after its passing in 2006. Continue to improve the article making sure all new information is properly sourced and neutral. I would recommend going through all of the citations and updating the access dates and fixing any dead links. If you have any questions, let me know on my talk page and I'll get back to you as soon as I can. I have updated the article history to reflect this review. Happy editing! --Nehrams2020 (talk) 08:30, 24 February 2009 (UTC)

Why are we using an RV minimum mass (3.75 Jupiter masses) as opposed to the astrometrically-derived true mass (10.25 Jupiter masses)? 46.126.76.193 (talk) 07:43, 24 November 2012 (UTC)

@Dren5144: I see that you restored the artist's impression that I removed, so I feel that I should explain why I removed it. At the outset, the image is not from a reliable source, making it in violation of WP:ASTROART. I don't want to just rely on guidelines, however, so will also point out that the image provides essentially no information about Upsilon Andromedae d, while having lots of potential to mislead readers. A big issue is that it depicts a watery, cloud-covered world. Upsilon Andromedae d, however, is likely to be a gas giant. Reading the caption, I see that the watery world pictured is, in fact, a moon of Upsilon Andromedae d, and the planet is in the background. First, the planet should be the most prominent feature of the lead image in its own article (I was confused and thought for a while that the thing is the foreground was the planet). Second, this planet is not known or even suspected to have any moons, much less Earth-like ones. Third, even ignoring the moon(s), there is no reason to believe this planet is stripey or purple or white. In conclusion, this image depicts no actual facts besides the sphericity of Upsilon Andromedae d, but depicts many things that are not known to be facts and are likely inaccurate. This is not a responsible, encyclopedic way to use an artist's impression. Per all of this, I am removing the image again. Feel free to re-revert, but please give your reasoning here if you do. A2soup (talk) 04:46, 16 January 2016 (UTC)


### Edit Undo
I readded the picture so readers could imagine it more and I know that is a hypothetical moon, although it clearly states that Upsilon Angromedae d is in the upper right of the picture and the object in the foreground is an imagined moon.  — Preceding unsigned comment added by Dren5144 (talk • contribs) 00:58, 19 January 2016 (UTC) 

So my view on this is that the purpose of an encyclopedia is not to help readers imagine, it is to inform them. Readers have this expectation of an encyclopedia, so when they see an image, they assume it is informative. Consequently, when images are intended to aid imagination rather than to inform, they are apt to mislead readers. It's pretty clear that this image is not informative (see my statement above), so it is likely misleading and in any case not appropriate for an encyclopedia.
@Dren5144: in view of this, would you be in favor of replacing this image with an informative one, such as a size comparison like this one? A2soup (talk) 02:19, 19 January 2016 (UTC)
I understand what you mean, A2soup.  — Preceding unsigned comment added by Dren5144 (talk • contribs) 12:47, 19 January 2016 (UTC) 

@Dren5144: So you would agree to replacing the artist's impression with a size comparison? A2soup (talk) 22:03, 19 January 2016 (UTC)
If I can.  — Preceding unsigned comment added by Dren5144 (talk • contribs) 00:53, 22 January 2016 (UTC) 
I have, A2soup.  — Preceding unsigned comment added by Dren5144 (talk • contribs) 01:13, 22 January 2016 (UTC) 
I didn't know , sorry.  — Preceding unsigned comment added by Dren5144 (talk • contribs) 22:26, 14 February 2016 (UTC) 

It's no problem-- I didn't notice it myself when I suggested a size comparison. A2soup (talk) 23:30, 14 February 2016 (UTC)

The Periastron and Apastron distances appear to slightly contradict the eccentricity amount given in this article. There is no source linked to a paper for the Semi-major axis, Periastron and Apastron figures. The figures given in this article are 2.54 AU for the Semi-major, 1.88 AU for the Periastron and 3.19 AU for the Apastron. However, when I took the Semi-major axis figure of 2.54 AU and then calculated the Periastron and Apastron from that, using the eccentricity given of 0.299, I got for the Pariastron 2.54*(1-0.299)=1.781 AU and for the Apastron 2.54*(1+0.299)= 3.299 AU. As can be seen, that is different to what is given in this article by about 0.1 AU in each case. Was a mistake made in the calculation for Apastron and Pariastron in this article or by me, was the calculation perhaps done on a different Semi-major axis figure or were the Apastron and Pariastron figures taken from a different paper to the one for eccentricity figure and that's why they don't seem to quite match each other?  — Preceding unsigned comment added by 86.151.235.166 (talk) 16:13, 21 October 2016 (UTC) 

Those values were added eight years ago before eccentricity was updated. PlanetStar 06:06, 22 October 2016 (UTC)

The image in the infobox should not be used as it does not follow the usage guide for the template:

This template is part of a group of templates that are used to display information about a specific extrasolar planet.
Images of published planetary properties are preferred where available, especially when they are available from cited publications.
Artist's conception, regardless of the source, should be avoided.
Examples of acceptable images include
* direct images, such as one used for GJ 758 b, in the rare cases where these are available;
* output of a model that is integral to a cited paper, such as the image used in HD 80606 b;
* user-generated images that clearly illustrate published properties, such as the size comparisons currently used in GJ 1214 b or Gliese 436 b.

My edits followed these guidelines but were revered by User:MarioProtIV. I'm opening discussion as to why ...
--EvenGreenerFish (talk) 09:26, 21 April 2017 (UTC)

I would like if the discussion was held here, rather then on all of the other pages. --MarioProtIV (talk/contribs) 11:19, 21 April 2017 (UTC)

This is an article about an exoplanet, so in that section, the habitability properties of planets should have been written only.
But we see that the moon habitability is written also!
Some parts are copied and pasted from Habitability of natural satellites article.
Also, in Exomoon article it is stated that the existence of exomoons aren't confirmed yet; so speaking about moon habitability in an article about exoplanets doesn't make any sense.
P.S. Sorry if I didn't make links. I am on mobile phone now. Aminabzz (talk) 13:34, 13 August 2023 (UTC)

The following Wikimedia Commons file used on this page or its Wikidata item has been nominated for deletion:

Upsilon Andromedae d.jpg
Participate in the deletion discussion at the nomination page. —Community Tech bot (talk) 17:23, 31 March 2021 (UTC)