Wikipedia:Featured article candidates/TRAPPIST-1/archive2

TRAPPIST-1

 * Nominator(s): Jo-Jo Eumerus (talk) 11:22, 25 July 2022 (UTC)

So, this was already at FAC but failed b/c of lack of supports and some prose concerns so it went through a second peer review during which some prose work was done. This is a star which is noted for the presence of seven planets in a harmonic chain, and some of these planets may even be habitable. Jo-Jo Eumerus (talk) 11:22, 25 July 2022 (UTC)

Image review
Nikkimaria (talk) 03:02, 26 July 2022 (UTC)
 * Several of the diagrams would benefit from being scaled up, but this should be done using upright rather than fixed px size
 * It looks like several already have that parameter. Any that would benefit from a higher number? Jo-Jo Eumerus (talk) 12:31, 26 July 2022 (UTC)
 * Possible interiors and the following animation, relative sizes, habitable zone. Nikkimaria (talk) 01:26, 27 July 2022 (UTC)
 * Did this for the non-animated images; one would need to click on the animation anyway to get useful information. Jo-Jo Eumerus (talk) 16:59, 27 July 2022 (UTC)
 * Some images are missing alt text
 * Did this? Jo-Jo Eumerus (talk) 12:31, 26 July 2022 (UTC)
 * There is no alt text for the infobox image, File:The ultracool dwarf star TRAPPIST-1 in the constellation of Aquarius.tif. For this, a short sentence describing the position of TRAPPIST-1 within Aquarius (similar to the article text) should suffice. All the remaining images are good. (I don't think the lack of alt text in the navboxes at the bottom is an urgent issue.) Complex / Rational  16:28, 9 August 2022 (UTC)
 * File:TRAPPIST-1_system_to_scale.svg should be cited to a non-circular source
 * I think Agol 2021, Grimm 2018 and Delrez 2018 are, but I'll ask for confirmation. Jo-Jo Eumerus (talk) 12:31, 26 July 2022 (UTC)
 * http://ncbi.nlm.nih.gov/pmc/articles/PMC5330437/table/T1 is another source, though its values are slightly different. cm&#610;&#671;ee&#9094;&#964;a&#671;&#954; 00:52, 29 July 2022 (UTC)
 * , can you add this source information to File:TRAPPIST-1_system_to_scale.svg? Jo-Jo Eumerus (talk) 08:36, 29 July 2022 (UTC)
 * Though I can do that, it might cause confusion, as the sources don't agree with one another, and thus the values in the diagram don't correspond to those in http://ncbi.nlm.nih.gov/pmc/articles/PMC5330437/table/T1 . I could put it a note that that source has slightly different values. cm&#610;&#671;ee&#9094;&#964;a&#671;&#954; 22:15, 30 July 2022 (UTC)
 * All what's needed here is a citation on the file page, rather than "data taken from Wikipedia", I think. Jo-Jo Eumerus (talk) 08:33, 31 July 2022 (UTC)
 * Jo-Jo Eumerus (talk) 08:24, 1 August 2022 (UTC)
 * File:TRAPPIST-1e_Const_CMYK_Print.png: source link is dead
 * Resolved. Jo-Jo Eumerus (talk) 12:31, 26 July 2022 (UTC)
 * File:Eso1733s_Artist's_impression_of_merging_neutron_stars.jpg appears not to be an ESO artwork - are we certain it would be covered by ESO's blanket license? *
 * Um, that image doesn't appear on the page? Jo-Jo Eumerus (talk) 12:31, 26 July 2022 (UTC)
 * It is - in one of the navboxes. Nikkimaria (talk) 01:26, 27 July 2022 (UTC)
 * The wonders of transclusion ... that said, the EXIF claims it's CC-BY-SA 4.0 Jo-Jo Eumerus (talk) 16:59, 27 July 2022 (UTC)

Comments from Artem
More later. Artem.G (talk) 14:50, 26 July 2022 (UTC)
 * As many as four of the planets (d, e, f, g) are hypothesised to be orbiting within the habitable zone[c][12] - do you really need this ref 12 in the lead? everything is referenced in the body.
 * No; removed it. Jo-Jo Eumerus (talk) 17:08, 26 July 2022 (UTC)
 * TRAPPIST-1 is in the constellation Aquarius,[13] only[14] five degrees south of the celestial equator.[d][1] - why does 'only' need a separate source? Is it that important?
 * Yes, there was a discussion on the peer review about this sentence. Jo-Jo Eumerus (talk) 17:08, 26 July 2022 (UTC)
 * In 2016, TRAPPIST-1's rotational period was first measured as 1.40±0.05 Earth days,[31] a typical period for M dwarfs.[43] 2017 measurements showed that the star actually rotates about every 3.295±0.003 Earth days,[8][44] though that may constitute the rotation period of active regions rather than stellar rotation according to a 2019 paper.[40] As of 2020, discrepancies between rotational data obtained by the Spitzer Space Telescope and Kepler satellite remain unexplained.[45] - I think it would be better if 2016 and 2017 events would be more implicitly accossiated with instruments, smth like "In 2016, data from the Spitzer show ... In 2017, Kepler measurements show ... As of 2020, discrepancies between those two remain unexplained."
 * I think the 2016 observations were from more than one source, but I added the Kepler thing in 2017. Jo-Jo Eumerus (talk) 17:08, 26 July 2022 (UTC)
 * Kepler satellite remain - why not 'Kepler space telescope'? Isn't it a common name?
 * Changed. Jo-Jo Eumerus (talk) 17:08, 26 July 2022 (UTC)
 * Based on a combination of techniques, an age of about 7.6±2.2 billion years has been established for TRAPPIST-1,[46] - maybe these combination can be added? (if it's not very important, maybe a note would work?)
 * It'd be pretty difficult to make it comprehensible without making it overly long, I am afraid. Jo-Jo Eumerus (talk) 17:08, 26 July 2022 (UTC)
 * while the Sun will leave the main sequence (run out of hydrogen[i]) - maybe just a link - run out of hydrogen - will work?
 * Eh, I don't think it's common knowledge what the "main sequence" is. Jo-Jo Eumerus (talk) 17:08, 26 July 2022 (UTC)
 * I suggested this construct during the peer review, and I feel that such a link might be a WP:SURPRISE. At that point in the text, if we're to add a link, hydrogen burning or similar feels more appropriate. ComplexRational (talk) 23:49, 26 July 2022 (UTC)
 * Possible faculae (bright spots[52]) - is this ref proves that faculae are bright spots? If yes, I think it's redundant. Same for albedo (reflectivity[136]). It just looks strange when there is a translation of 'faculae' or 'albedo' (especially for 'albedo' as a common word in astronomy), and there are no explanation of stuff like Alfvén surface, planet's Hill radius, global Rossby number, etc.
 * Some of these are explained in text, I think. Jo-Jo Eumerus (talk) 17:08, 26 July 2022 (UTC)
 * As of 2017, this is the largest known number of planets within the habitable zone of a star or star system.[135] - what about 2022?
 * It is not feasible to keep an article - even at FA standards - up to date on a monthly basis. Thus I only do it once per year during Christmas, hence any 2022 publication isn't used yet. Jo-Jo Eumerus (talk) 17:08, 26 July 2022 (UTC)
 * making TRAPPIST-1b a candidate magma ocean planet - link magma ocean (it was linked before, but would be useful here)
 * Done. Jo-Jo Eumerus (talk) 17:08, 26 July 2022 (UTC)
 * Models of tidal effects on TRAPPIST-1e have been created.[242] - maybe any details about these models are worthy and can be included?
 * I'd prefer to leave them to TRAPPIST-1e. Jo-Jo Eumerus (talk) 17:08, 26 July 2022 (UTC)


 * For each section about a planet you have {Main article} and then start sentence with the planet's name. Maybe it can be simplified - insert links into first sentences and remove {Main}? (just a thought, I have no hard feelings of either variant)
 * I think the current form makes it clearer that detailed information on each planet is found elsewhere. Jo-Jo Eumerus (talk) 10:07, 28 July 2022 (UTC)
 * The discovery of the TRAPPIST-1 planets is often incorrectly attributed to NASA - 'often' is referenced by one source, maybe 'sometimes attributed to NASA'?
 * This was a tough one. It certainly seems to me like NASA is frequently (not just "sometimes") mentioned as the discoverer. Jo-Jo Eumerus (talk) 10:07, 28 July 2022 (UTC)
 * The speculative Breakthrough Starshot proposal for sending small laser-accelerated unmanned probes would require around two centuries to reach TRAPPIST-1.[305] - link is dead
 * Changed. Jo-Jo Eumerus (talk) 10:07, 28 July 2022 (UTC)

Besides these comments, I can't find any serious flaws - as the article was under PR and FAC before, I think everything was polished several times. Nice article, I support it being promoted to FA status. Artem.G (talk) 06:42, 28 July 2022 (UTC)

Comments from Edwininlondon
I'm glad to see this back here again. I reviewed it last time around. The prose flows much better now. My comments: That's it from me. Edwininlondon (talk) 10:50, 31 July 2022 (UTC)
 * telescope at La Silla Observatory --> perhaps add which country this is in
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * have precise numerical ratios of 8:5 --> it is not obvious what the ratio is of, so perhaps add "of neighboring planets have precise.."
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * the formation of the planetary system --> link planetary system
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * of the planets including --> of the planets, including
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * whether planets could retain --> whether the planets could retain
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * exoplanets should be linked
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * Dwarf stars like TRAPPIST-1 --> this seems out of order, as not until the next paragraph are we told it is a red dwarf.
 * Yes, but I'd like to first introduce general information before specific one. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * Its luminosity is --> link
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * a typical period for M dwarfs --> I thought it was a red dwarf? somewhere earlier it needs to state it is an M dwarf, with explanation or at least a link
 * Per our article, they are (mostly) synonyms. I don't have a source for its definition. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * I see. But we have to say this somewhere, perhaps right after where you talk about its temperature. Something like "TRAPPIST-1 has an effective temperature[h] of 2,566 K (2,293 °C; 4,159 °F), making it fall within the definition of an M dwarf."
 * AFAIK the definition is mostly a matter of spectrum, only indirectly of temperature. Added a note for red dwarf to explain that. Jo-Jo Eumerus (talk) 21:41, 31 July 2022 (UTC)
 * Sorry to be a pain, but I'm not convinced adding a note is good enough. I don't think we can rely on users reading the note. As it stands now "typical period for M dwarfs" is puzzling because the reader has not been told whether Trappist-1 is an M dwarf or not. Can this not be stated? For instance right after stating it is a red dwarf?
 * Recast this. Jo-Jo Eumerus (talk) 08:24, 1 August 2022 (UTC)
 * the Kepler space telescope --> link here, delink in the next sentence
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * the star actually rotates about every 3.295±0.003 Earth days,[8][44] though that may constitute the rotation period of active regions rather than stellar rotation --> given the caveat, I don't think the word "actually" is appropriate.
 * Rewritten. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * making it almost twice as old as the Solar System --> I don't think we should say this. Not with that 2.2 error range. Just say older, like you have in the lead
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * about 700 times[48] longer than the present age of the Universe --> I don't think this is helping. It interrupts the main point about the sun comparison. I would delete it.
 * Well, this paragraph discusses both the past and the future of the star sequentially, so I wouldn't agree. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * OK, if you want to hang on to it, then make it at least easier for the reader to understand your point by not intertwining two comparisons. So something like "The life expectancy of a small, faint star like TRAPPIST-1 is hundreds to thousands of times longer than that of stars like the Sun:[27] TRAPPIST-1 is expected to shine for ten trillion years, while the Sun will leave the main sequence (run out of hydrogen[i]) in a few billion years. TRAPPIST-1's life expectancy is about 700 times[48] longer than the present age of the Universe."
 * I am kind of concerned about inserting the solar lifespan in the middle of the sentence as that proposal does. Jo-Jo Eumerus (talk) 21:41, 31 July 2022 (UTC)
 * Sorry for being so astronomically clueless, but the way I understand what you have now is as follows: 1) "The life expectancy of a small, faint star like TRAPPIST-1 is hundreds to thousands of times longer than that of stars like the Sun:" == comparison to Sun lifespan. 2) "TRAPPIST-1 is expected to shine for ten trillion years" = absolute TRAPPIST-1. 3) "about 700 times[49] longer than the present age of the Universe" = comparison to Universe. 4) "while the Sun will leave the main sequence (run out of hydrogen[j]) in a few billion years" = absolute Sun. I had a hard time understanding 1) because 3) is in the middle of 2) and 4). To me as a layman person 2) and 4) should be next to each other in order to make sense of 1), which has a colon to tell me what is coming.
 * Attempted a rewrite. Jo-Jo Eumerus (talk) 08:24, 1 August 2022 (UTC)
 * NASA Exoplanet Archive --> link
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * between Mars-sized to slightly larger than Earth --> this assumes the reader knows the size of Mars. Better to put this after the next sentence.
 * I don't think that would be clearer. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * requiring lower-density molecular species to be present --> is this species the right word? Smells of life ...
 * At least in the jargon, it is. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * Is there a way to avoid the jargon as per MOS:JARGON?
 * Yes, and that's in. Jo-Jo Eumerus (talk) 21:41, 31 July 2022 (UTC)
 * it would causing --> ?
 * Corrected. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * facilitating --> facilitate?
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * This is particularly important early in the star's history, when radiation was --> present tense and past mixed
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * existing telescopes and observations cannot infer --> inanimate objects indeed can not infer
 * Specified. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * including oceans over hundred times larger than Earth's --> this puzzles me: the biggest planet is estimated to be 150% size of Earth. the Pacific covers a third, so how do we get to 100?
 * The vertical dimension also counts. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * if there are not other gases --> if there are no other gases
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * additional hurdle for atmospheres --> delink atmospheres
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * M dwarfs have intense flares. TRAPPIST-1 has about 0.38 flares per day[12] and about 4 to 6 superflares[z] per year. --> should this info not live in the Star section?
 * This is more important here. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * Samara, Patsourakos and Georgoulis 2021 --> this format differs from the X et al. (2019) you used before
 * Matched. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * The stellar wind from TRAPPIST-1 has a pressure a thousand times larger --> this seems to be at odds with "The stellar wind properties of TRAPPIST-1 are not precisely determined."
 * Corrected. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * Stellar wind-driven escape in the Solar System is largely independent on planetary properties such as mass[219] and could remove the atmospheres of TRAPPIST-1 planets --> mixing Solar System with Trappist
 * Recast. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * may have lasted for hundreds of millions[204] and up to two billion years --> may have lasted for between hundreds of millions[204] or up to two billion years
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * orbits its star every 2.42 d --> orbits its star every 2.42 Earth days
 * Sorry, but I dunno how to make that work. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * Am I missing something? 1b "orbits its star in 1.5 Earth days". 1d "has an orbital period of 4 Earth days". Is it not possible to express 1c's orbital period in Earth days? It would be really good to have consistency.
 * Yes, the formatting template. I don't see how to make it pronounce the units. Jo-Jo Eumerus (talk) 21:41, 31 July 2022 (UTC)
 * Can you not use what worked for Trappist-1b? "and orbits its star in $2.42$ Earth days" Or am I missing something obvious again?
 * That's done. Jo-Jo Eumerus (talk) 08:24, 1 August 2022 (UTC)
 * the oribital periods for e f g h are missing
 * Still. Or are they not known?
 * Added. Jo-Jo Eumerus (talk) 21:41, 31 July 2022 (UTC)
 * TRAPPIST-1e is the TRAPPIST-1 planet most likely to have water --> this was just said in the previous paragraph
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * TRAPPIST-1f could have kept up to several Earth ocean masses of water[12] that could make up as much as 50% of the planet's mass --> again, is "several times" not a bit much, given that the biggest planet is only 150% size of Earth? Or are the oceans on 1e to be expected much much deeper than Earth's?
 * They can be much deeper, yes. Water/planet mass ratios are not at all conserved. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * Large quantities of carbon dioxide, as well as hydrogen or methane[245] --> delink
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * the star is considered a promising site --> the star's planets I assume
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * Mullan and Bais 2018 ... Lingam and Loeb 2019 --> again, different formatting from X et al. (2019) you used before
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * The outer planets in the TRAPPIST-1 system could feature subsurface oceans --> should this not be mentioned in the sections about the outer planets?
 * No, because the statement pertains to more than one planet. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * (from the viewpoint of TRAPPIST-1) --> I feel this is in the wrong position. It should be after "the Sun"
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * close-by ultra-cold dwarf stars --> is there a reason you use cold and not cool?
 * Matched. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * Its planetary system was discovered by --> delink here and link first use of planetary system in body article
 * Done. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * with their orbits constrained by the Spitzer and Kepler telescopes --> what does this mean? How do telescopes constrain an orbit?
 * Corrected. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * The movement of a stellar body with respect to the sky, rather than the movement of the body itself --> The other footnotes seem to include what it is they are explaining, but this one does not
 * Corrected. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * That was a lot of things, but I think I got most. Jo-Jo Eumerus (talk) 16:15, 31 July 2022 (UTC)
 * Indeed. Just a few points left. Edwininlondon (talk) 21:08, 31 July 2022 (UTC)
 * I'm happy my points have been addressed. I Support on prose. Edwininlondon (talk) 15:58, 9 August 2022 (UTC)

Comments (support) from ComplexRational
As I noted at the close of the peer review, I'm quite pleased with the improvements to this article since FAC1. I just gave it another quick review (having done the bulk of reviewing during the PR) and pending a few minor comments, I'm happy to support promotion to FA. Good work! Complex / Rational 16:58, 9 August 2022 (UTC)
 * I made a few minor formatting fixes, removed a couple of duplinks, and changed a second occurrence of magma ocean (in the section TRAPPIST-1b) to the more specific lava planet.
 * See my comment above re alt text – the infobox image doesn't have it, but it can be written to reflect the article text.
 * Template:Starbox image does not have an option for ALT text, it seems like. Jo-Jo Eumerus (talk) 17:39, 9 August 2022 (UTC)
 * Would it work to specify  in the file link itself? I don't see anything suggestive of the contrary.  Complex / Rational  22:38, 9 August 2022 (UTC)
 * Let's see if it shows up. Jo-Jo Eumerus (talk) 10:41, 10 August 2022 (UTC)
 * Indeed it does in the alt text viewer (toolbox). I might also suggest mentioning that TRAPPIST-1 is located very close to the ecliptic. Complex / Rational  16:21, 10 August 2022 (UTC)
 * I already noted this in one case at the PR – sources published by exactly the same authors in the same year should be distinguished, e.g., 2014a, 2014b, per this and similar guidelines. This is nicely done in some cases, though I've noticed a few instances of broken numbering (e.g., there's a Gillon 2020b but no Gillon 2020a) as well as slightly different author listings. I propose standardizing the authors (even with et al.) and numbering sequence.
 * I think I got these? Jo-Jo Eumerus (talk) 17:39, 9 August 2022 (UTC)
 * Still needs a bit of work. In the list of sources, months and days are also provided in some cases, which serve to distinguish the sources there. I'm not sure if style guidelines permit, e.g., "April 2018a" and "July 2018b" unless there are multiple papers from either month with exactly the same authors. In these cases, it should suffice to leave them without letters in the list (using letters only as a "last resort" when authors and dates are not sufficient), but rather distinguish them using WP:CITEREF; thus, the list would include April 2018 and July 2018 but the footnotes would use 2018a and 2018b, respectively.
 * Also, I think you might have missed that there's still a 2011b without a 2011a – there's only one paper by Prantzos on the list. Complex / Rational  22:38, 9 August 2022 (UTC)
 * Did that one, I don't know about CITEREF enough to make a change on the April and July things. Jo-Jo Eumerus (talk) 10:41, 10 August 2022 (UTC)
 * It's similar to harvid, which is already used and I hadn't noticed. I made the change here and it seems to work. Complex / Rational  16:21, 10 August 2022 (UTC)


 * Hi, I was wondering if you had intended the last part of your review to be a source review? Thanks. Gog the Mild (talk) 21:01, 24 August 2022 (UTC)
 * I hadn't planned on doing a source review; that was just one last detail that wasn't fully resolved in the peer review. Since I don't have time to commit now, if a source review is required, I would appreciate it if someone else handled it. Complex / Rational  21:20, 24 August 2022 (UTC)
 * Thanks, that's fine. I had assumed it wasn't, but you know what they say about "assume" - it seemed best to check. Gog the Mild (talk) 11:58, 25 August 2022 (UTC)

Comments from Sportsfan77777
I'll review the article. Sportsfan77777 (talk) 21:54, 10 August 2022 (UTC)

Lead
 * What's rationale for calling TRAPPIST-1 just a star as opposed to a "planetary system" or a "star with a planetary system" (i.e. a "stellar system")? The website calls it a "planetary system" and I would think that when most people say TRAPPIST-1 they are referring to the planetary system, not specifically the star. (i.e. The equivalent article is the solar system, not the Sun.)
 * The article covers both, unlike Sun-Solar System, but added planetary system. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * Related to that, I would suggest mentioning TRAPPIST-1 has seven known planets in the first paragraph to give that more emphasis. The current placement of that makes it a bit buried.
 * Also done. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * "with the shortest period being" <<<=== suggest rephrasing the sentence to avoid the with "-ing" issue.
 * Done. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * Also suggest rephrasing that sentence to put the range of orbital periods first (1.5 to 18.8 days) and then add that they are in resonance afterwards. It's much easier to understand the length of the year part than the resonance part.
 * Done. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * "The habitable zone is the region around a star where temperatures are neither too hot nor too cold for the existence of liquid water" <<<=== "could be" neither too hot nor too cold for the existence of liquid water. (see e.g. )
 * I dunno, usually one would say a planet too cold or too warm is outside of the habitable zone. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * As many as four of the planets (d, e, f, g) are hypothesised to be orbiting within the habitable zone[c] of the star and thus to have temperatures suitable to the presence of liquid water and the development of life. <<<=== Suggest rephrasing to make it clear that what's uncertain is the extent of the habitable zone, as well as possibilities of water and life, not the orbits. The current wording sounds to me like the orbits are uncertain.
 * Did this, but I sort of don't like the formulation. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)

Star
 * only[14] <<<=== suggest not citing "only" or moving the citation to the end of the sentence
 * Done. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * Dwarf stars like TRAPPIST-1 are over ten times more common than Sun-like stars[27] and these stars are more likely to host small planets than Sun-like stars. <<<=== This sentence is out of place. It should be in the next paragraph after it's stated that TRAPPIST-1 is a red dwarf. (albeit see the new few comments) Also, careful: "dwarf" doesn't mean "small", it means "not a giant star, i.e. stars either on the main sequence or below the main sequence".
 * Done. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * "TRAPPIST-1 is a red dwarf;[30] red dwarfs are cold stars with" <<<=== suggest avoiding these types of constructions in general. You could use a construction like "TRAPPIST-1 is a red dwarf,[30] a cold star with... "
 * Done. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * red dwarfs are cold stars with a mass less than the Sun, including the spectral types M and K,[31] ad TRAPPIST-1 belongs to class M <<<=== I don't think this captures what a red dwarf is. Suggest "TRAPPIST-1 is a red dwarf, the smallest, coolest, and most common type of star". I would lean towards thinking mentioning K dwarfs is not relevant.
 * Need a sauce for such a formulation, and I think that not mentioning K dwarfs would be slightly misleading. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * I think "cool" is preferred to "cold". "cool" is a jargon term. (It's not actually cold, it's a few thousand degrees. That's really hot!)
 * Done. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * "Spectral type" is introduced twice in the second paragraph. You should mention "M8.0" when introducing the spectral type.
 * Done. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * which is a scheme to categorise stars by their temperature <<<=== I'm not sure this captures the point. "Spectral type" categorises stars by their spectra, hence the name "spectral type". For main sequence stars, that classification implies a bunch of other properties including temperature, mass, lifetime, etc.
 * I don't think it does, but the problem is that definitions like these are hard to source. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * Link spectral type to Stellar classification.
 * Done. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * it has only barely sufficient mass to allow nuclear fusion to take place <<<=== this is related to the mass not the radius, but it's in the radius sentence
 * Done. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * Suggest starting the rotation period paragraph by noting the disagreement
 * It's somewhat hard to explain things when put in that order. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * You could compare the rotation period to the Sun.
 * I don't think the rotation period is as important as the mass and luminosity, myself. Plus, it'd need another sauce for the Sun's rotation period. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)
 * "to shine" <<<=== this is too informal. I assume you mean "stay on the main sequence"?
 * Kind of, but "shine" captures the pertinent aspect. Jo-Jo Eumerus (talk) 16:43, 11 August 2022 (UTC)

More commments later. In general, I think the quality of explanations could still be improved. Sportsfan77777 (talk) 23:14, 10 August 2022 (UTC)
 * Sportsfan77777, any more to come? Thanks. Gog the Mild (talk) 17:38, 22 August 2022 (UTC)

Planetary system
 * 1,700,000 kilometres (1,100,000 mi) to 8,900,000 kilometres (5,500,000 mi) <<<=== I would think AU would be a logical default choice of units. (Does 1 million km mean something to a typical reader?) If it were me writing the article, I would also add the distances in stellar radii to elucidate the proximity to the star.
 * The AU thing's a reasonable suggestion so it's in. I don't think that the radii of TRAPPIST-1 are known with such precision or so well-known that we could use them as a reference, though. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)
 * A hypothetical eighth planet would be designated TRAPPIST-1i, and its orbital properties have been predicted under the assumption that it orbits exterior to planet h and is part of the planetary resonance <<<=== I would suggest removing the passive voice, as it makes the sentence more confusing. It's also strange to say the properties of have predicted without saying what that orbit would be.
 * I am hearing you, but I am not sure how to formulate it otherwise ... also, it does say that we have an idea of what the orbit of an eight body in the resonance would look like. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)
 * In a 2018 paper, the authors <<<=== I would suggest not using "paper" in general (it's too informal), and just refer to the paper directly (i.e. Kral et al. 2018) or name the authors and year separately (In 2018, Kral et al. OR In 2018, Quentin Kral et al.), or if you'd prefer a similar construction, use "a 2018 study".
 * Went for the format used by other paper mentions. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)
 * Most of the pre-planetary material was converted into planets <<<=== Rephrase so it doesn't sound so concrete. I don't think it's known for sure that this is the case.
 * Done. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)
 * Also, I don't think "pre-planetary" is a real term. Either "solid material" or "rocky material" or both together "solid rocky material"
 * Done. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)
 * spin axis ot TRAPPIST-1 <<<=== typo
 * Done. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)
 * "on the same plane" ===>>> "in the same plane"?
 * Done. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)
 * The planets all orbit on the same plane and, from the perspective of the Solar System, move past TRAPPIST-1 during their orbit <<<=== This would be a good place to introduce transits, i.e. just say "transit in front of TRAPPIST-1"
 * Done, not sure if the quote marks are needed. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)
 * 0.775±0.014 <<<=== suggest using the +0.014 −0.014 to keep it consistent with the others
 * Done. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)

Size and composition
 * Observations indicate that sizes of the planets range from between Mars-sized to slightly larger than Earth.[86] Their radii are estimated to lie within the range of 75% to 150% that of Earth. <<<=== Condense into one sentence. These are the same thing, but it sounds like they are different things.
 * Done but a slight reformulation may be needed. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)
 * consist of large amounts of atmospheres, ice and oceans <<<=== "large amounts of atmospheres" and "large amounts of oceans" aren't proper phrasing
 * Rewrote this. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)

Resonances
 * results in strong tidal interactions ===>>> result in strong tidal interactions
 * Done. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)
 * which would have important implications for the climate of the planets <<<=== It does not say what those implications on the climate are
 * Because the source does not specify; it refers to https://www.aanda.org/articles/aa/pdf/2016/12/aa29577-16.pdf which does discuss the outcomes for a different planet (Proxima Centauri b) Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)
 * which potentially makes the planets more habitable <<<=== It's unclear if this part is referring to the tidal locking or the chaotic rotations making them potentially more habitable.
 * Clarified. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)

Stellar light
 * Okay.

Habitable zone
 * Okay.

Moon
 * Might want to clarify that no moons have been detected in general around any exoplanet even close to as small as the ones in the TRAPPIST-1 system
 * Eh, I don't think it's necessary; we only have one or two disputed exomoons, period. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)

Magnetic
 * ; the Alfvén surface is the area around the star ===>>>, the area around the star
 * Done. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)

Formation
 * Suggest citing the Ormel et al. (2017) sentence with that paper instead of just putting the citation in the footnote.
 * In this case I prefer to use the secondhand mention as a reference. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)
 * gave rise to precursor bodies <<<=== suggest using "planetary embryos" instead of "bodies"
 * Done. Jo-Jo Eumerus (talk) 13:03, 4 September 2022 (UTC)

More comments later, hopefully later today. Sportsfan77777 (talk) 11:55, 4 September 2022 (UTC)


 * Actually, I don't think I'm going to have much free time any time soon. Seeing as it looks like it's going to pass if I just abandon the review and since I already commented on the main things I wanted to comment on, I'm going to leave it at that. Sportsfan77777 (talk) 21:50, 18 September 2022 (UTC)

Oppose from Sandbh
I want to support this FAC but concerns raised at FAC1 about the writing not seeming to be up to the high quality FA standard, and a lot of basic copyediting which would have been better done off-FAC and suggesting the article wasn't ready for FAC2 when it was nominated, remain outstanding.

Some examples of writing concerns follow.

Lede para 1, 1st sentence: "TRAPPIST-1 is an ultra-cool red dwarf star in the constellation Aquarius with a planetary system of seven known planets."

Lede para 2, 1st sentence: "The star was discovered in 2000."

Comment. Since para 1, starts off with a reference to a "star" it is not necessary for para 2 to again refer to the "star".
 * On this one I have to disagree: The star and the planetary system weren't discovered at the same time, so yes we need to specify what "2000" refers to. Jo-Jo Eumerus (talk) 09:16, 30 September 2022 (UTC)
 * Yes, a reader who is very familiar with the subject matter may appreciate this nuance. OTOH, as a general reader, I found this doubling up to be off-putting. It now occurs to me that since the article is about TRAPPIST-1, rather than its planetary system, there is no pressing need to distinguish between the star and its planetary system, in that way. Sandbh (talk) 04:23, 2 October 2022 (UTC)
 * While I understand the sentiment, the problem I have with the rewrite is that it is actively misleading. Even for a general reader that would be bad. Jo-Jo Eumerus (talk) 10:36, 2 October 2022 (UTC)
 * I don't think the distinction between a star and the planets orbiting it is "nuance", really. We're talking about the discoveries of very different kinds of objects, discoveries that were separated by years. XOR&#39;easter (talk) 16:35, 2 October 2022 (UTC)

Lede, para 3: 1st sentence, "The orbits of as many as four of the planets (d, e, f, g) may correspond within the habitable zone[c] of the star and thus to have temperatures suitable to the presence of liquid water and the development of life."

Comment. The "and thus to far" makes no sense.
 * I don't see any "and thus so far"? Jo-Jo Eumerus (talk) 09:16, 30 September 2022 (UTC)
 * It appeared in the version of the article I was looking at, here.
 * Sorry, but I can't find it even there. Is there an extra space or something. Jo-Jo Eumerus (talk) 09:28, 3 October 2022 (UTC)
 * From my notes, I was concerned about "and thus to have". I don't know where I got the "far" from, sorry. No matter since this example has since been fixed. Sandbh (talk) 05:59, 4 October 2022 (UTC)

Rotation period and age 2nd sentence: "2017 measurements by the Kepler space telescope showed that the star may instead rotate about every 3.295±0.003 Earth days,[8][47] though that may constitute the rotation period of active regions rather than stellar rotation according to Miles-Páez et al. (2019).[43]"

Comment. Don't start a sentence with a number.

Para 2: "...TRAPPIST-1 is expected to shine for ten trillion years – about 700 times[51] longer than the present age of the Universe[52] – while the Sun will leave the main sequence (run out of hydrogen[k]) in a few billion years.[51] The life expectancy of a small, faint star like TRAPPIST-1 is hundreds to thousands of times longer than that of stars like the Sun.[40]"

Comment: The last sentence is redundant.
 * Looks like someone else resolved these issues. Jo-Jo Eumerus (talk) 09:28, 3 October 2022 (UTC)

Activity "Numerous photospheric features detected on TRAPPIST-1 may introduce inaccuracies in measurements of its planets.[54] Possible faculae (bright spots[55]) have been observed by the Kepler space telescope and Spitzer Space Telescope,[56] but some of TRAPPIST-1's bright spots may be too large to count as faculae.[57] Their effect on the luminosity of TRAPPIST-1 may lead to the planets' densities being underestimated by 8+20−7 percent,[58] and to incorrect estimates of their water content.[59] A correlation between bright spots and flare[l] activity has been found.[35] The mean intensity of TRAPPIST-1's magnetic field is about 600 G[61] although many of its properties cannot be directly measured.[62] This intense magnetic field is driven by chromospheric[m] activity[12] and may be capable of trapping coronal mass ejections.[n][60][64]"

Comment. I do not understand the need for this sentence: "A correlation between bright spots and flare[l] activity has been found.[35]"
 * This section describes the activity of the star, I thought it would be relevant information. Jo-Jo Eumerus (talk) 09:28, 3 October 2022 (UTC)
 * The context is disrupted due to the sentence between, "Possible faculae (bright spots[55]) have been observed by the Kepler space telescope and Spitzer Space Telescope,[56] but some of TRAPPIST-1's bright spots may be too large to count as faculae.[57]" and "A correlation between bright spots and flare[l] activity has been found.[35]" Sandbh (talk) 05:59, 4 October 2022 (UTC)
 * Corrected that one. That said, since we are just correcting examples, I think I need to ask whether folks think that the issues can be resolved within the confines of FAC. Jo-Jo Eumerus (talk) 12:43, 4 October 2022 (UTC)

Size and composition Para 2: "The densities are too low for a pure magnesium silicate composition, requiring lower-density molecular compounds to be present,[94] such as water."

Comment: The relevance of a pure magnesium silicate composition is not clear.
 * This is outside my specialization, but I think the meaning is that pure magnesium silicate is as light as rocky material can get, so to account for the low overall density, material of even lower density (like water) must be present. XOR&#39;easter (talk) 15:34, 1 October 2022 (UTC)
 * Added a footnote. Jo-Jo Eumerus (talk) 09:28, 3 October 2022 (UTC)

Resonance "It could be sufficient to melt the mantles of the four innermost planets, in whole or in part,[124] it would cause the development of subsurface magma oceans in some planets;[125] increase the degassing[u] from the mantle and facilitate the establishment of atmospheres around the planets.[127"

Comment. The construction of this para is clumsy. At 45 words it is too long.
 * Shortened that one. Jo-Jo Eumerus (talk) 09:28, 3 October 2022 (UTC)

I suggest the article be copy edited by an uninvolved editor. Sandbh (talk) 08:19, 30 September 2022 (UTC)
 * can I ask if you have any suggestions for editors who can do the copyediting? I am not going to try peer review for the third time, that doesn't work. Jo-Jo Eumerus (talk) 09:16, 30 September 2022 (UTC)
 * I've found GOCE to be helpful although I think they are very backlogged at this point. (t &#183; c)  buidhe  15:47, 30 September 2022 (UTC)
 * Jo-Jo thx for the ping, and I sincerely apologize for losing the plot here; real life medical issues have wreaked havoc with my time lately. One editor who might be able to help bring this over the hump is  and I don't know whether  has more time to help with the ce. Others that come to mind are .  I wish I could help more, but it is going to be quite some time before I catch up. Sandy Georgia  (Talk)  15:15, 1 October 2022 (UTC)
 * I already offered some feedback at the PR to help get the article into better shape pre-FAC. While I'm unsure how much free time I'll have in the next few days/weeks to do substantial copyediting, I'll keep watch and point out anything I find. Complex / Rational  21:15, 4 October 2022 (UTC)
 * I have seen this but am rather busy; I'll look when I can find time, though. Double sharp (talk) 20:28, 9 October 2022 (UTC)
 * I'm afraid I have a fair amount on my (on- and off-wiki) plate right now and haven't even been properly keeping up with the other FARs. If Planet gets closed and I finish up Yellowstone fires, I'll look at this one. Edit: I actually thought this was an FAR, not an FAC. So unfortunately I won't be able to contribute in a reasonable time. Ovinus (talk) 21:39, 9 October 2022 (UTC)

When the article is ce'd I recommend that the logical flow of the paragraph topic sentences is checked. For example, in the Resonance section, the topic sentences go in this order:


 * 1) The planets are in orbital resonances,[101] with the durations of their orbits having ratios of 8:5, 5:3, 3:2, 3:2, 4:3, and 3:2 between neighbouring planet pairs,[102] and with each triplet being in a Laplace resonance.
 * 2) The close distances of the planets to the host star TRAPPIST-1 result in strong tidal interactions,[108] stronger than for Earth.[109]
 * 3) The resonances continually excite the eccentricities of the TRAPPIST-1 planets, preventing their orbits from becoming fully circular.
 * 4) Even if tidal heating does not significantly alter the climates of the planets, tidal heating could influence the temperatures of the night sides and cold traps, where gases are expected to accumulate; it would influence the properties of subsurface oceans[121] where volcanism and hydrothermal venting[t] could occur.

Whereas it appears the logical flow would be stronger if the order was: 1, 3, 2, 4. Sandbh (talk) 04:23, 2 October 2022 (UTC)
 * The tidal interactions are the reason why the eccentricities get excited, so I wouldn't agree. Jo-Jo Eumerus (talk) 10:36, 2 October 2022 (UTC)
 * I'm fine with the current ordering of the paragraphs in "Resonance". XOR&#39;easter (talk) 16:38, 2 October 2022 (UTC)
 * As a general reader, I don't know that the tidal interactions are the reason why the eccentricities get excited. Nor does the current sequence of four topic sentences make this clear. In the first topic sentence, what is a "triplet"? Sandbh (talk) 03:59, 3 October 2022 (UTC)
 * Another concern is that the information about the planets is split between two sections. Frex, in the Planetary system section there is a table called "The TRAPPIST-1 planetary system". About 5 screens down, in the List of Planets section, there is another table called "Other characteristics". Why is it necessary to split the data between two different sections, into two tables? Could there not be one consolidated table? A related concern is the structure of the article, as follows:

2	Planetary system 3	Potential atmospheres of the planets 4	List of planets


 * Why are sections 2 and 4 not consolidated?
 * --- Sandbh (talk) 04:32, 2 October 2022 (UTC)
 * That was a deliberate decision, so that folks can go from the general traits of the system to the list of specific planets. Jo-Jo Eumerus (talk) 10:36, 2 October 2022 (UTC)

I'll have another look and let you know. Sandbh (talk) 03:58, 12 October 2022 (UTC)
 * Hi Sandbh, just checking to see if your oppose still stands? Thanks. Gog the Mild (talk) 20:29, 11 October 2022 (UTC)


 * I'm not pleased to say that my oppose still stands. The items I listed formed only a sample of my concerns. There were several more which I did not list as I considered that the items I did list were sufficient to show that the article needed a thorough copy edit, which it has not yet undergone. Here are some more concerns:


 * Activity[edit]
 * Numerous photospheric features detected on TRAPPIST-1 may introduce inaccuracies in measurements of its planets.[54] Possible faculae (bright spots[55]) have been observed by the Kepler space telescope and Spitzer Space Telescope,[56] but some of TRAPPIST-1's bright spots may be too large to count as faculae.[57] A correlation between bright spots and flare[l] activity has been found.[35] The effect of bright spots on the luminosity of TRAPPIST-1 may lead to the planets' densities being underestimated by 8+20 −7 percent,[59] and to incorrect estimates of their water content.[60] The mean intensity of TRAPPIST-1's magnetic field is about 600 G[61] although many of its properties cannot be directly measured.[62] This intense magnetic field is driven by chromospheric[m] activity[12] and may be capable of trapping coronal mass ejections.[n][58][64]


 * The topic sentence does not make sufficient sense to me. What are "photospheric" features? The second sentence says that bright spots may be too large to count as faculae, but does not sufficiently explain the "so what" if the spots are too large to count as faculae.


 * Stars lose mass through the stellar wind.[65] Garraffo et al. (2017) computed the mass loss of TRAPPIST-1 to be about 3×10−14 solar masses per year,[66] about 1.5 times that of the Sun,[67] while Dong et al. (2018) simulated the observed properties of TRAPPIST-1 with a mass loss of 4.1×10−15 solar masses per year.[66] The stellar wind properties of TRAPPIST-1 are not precisely determined.[68]


 * The topic sentence is not specific to Trappist-1. For that matter, what is "the stellar wind"? The sentence would read better as something like, "Trappist-1 loses mass due the activity of...Garraffo et al. (2017) computed the magnitude of the loss to be...". Dong et al.'s figure should also be expressed in terms of how many times it is that of the sun.


 * Size and composition
 * The radii of the planets are estimated to lie within the range of 75% to 150% that of Earth,[88] equivalent to Mars-sized to slightly larger than Earth


 * 150% is not "slightly" larger than Earth.
 * I think I'll need a synonym here ... I think that "larger" on its own implies that such a radius is significantly different from Earth's, but in the context of exoplanetology 150% is only "slightly" larger. Jo-Jo Eumerus (talk) 12:43, 20 October 2022 (UTC)
 * Since we need more science-topic FA's I regret to say that while the article appears to be technically accurate it does not yet meet the FA well-written criterion. Sandbh (talk) 06:10, 13 October 2022 (UTC)

If my lede edits were satisfactory (let me know?) I might be able to help here. Not sure if this is just a copy edit or if it goes beyond that. czar 17:34, 15 October 2022 (UTC)
 * That edit seems OK to me, although I wouldn't say "atmosphere as a precondition for life" as it's implicit in the scientific discourse rather than explicitly stated. Jo-Jo Eumerus (talk) 08:14, 16 October 2022 (UTC)
 * Feel free to edit that as would be appropriate, as I'm just attempting to paraphrase what was previously there.
 * The part that keeps me from copy editing further is not knowing how far this article needs to go to be comprehensible to a general reader or if we're just shooting for an advanced college student in astronomy as the target audience. I'd lean towards the former in a copy edit, which would include footnoting a lot of detail, such as items it wouldn't make sense to say when reading the article out loud. It looks like the last star FA was Rigel in July 2020 and it wasn't held to that standard then. Without looking at precedent, those are the edits I would want to make for today's bar of FA quality. czar  17:59, 22 October 2022 (UTC)
 * Well, it depends. In your judgment, how much work would it be to achieve the former? I know that people complain about excessive footnotes but well, you sometimes can't have it both ways (explained and short) Jo-Jo Eumerus (talk) 09:47, 23 October 2022 (UTC)

Source review
Footnote numbers refer to this version. Will look at source reliability next. Mike Christie (talk - contribs - library) 20:07, 10 October 2022 (UTC)
 * Check for p/pp errors in FNs 3, 206, 227.
 * Regarding the first, I don't know how to use that source; perhaps know how. Other two done. Jo-Jo Eumerus (talk) 09:19, 11 October 2022 (UTC)
 * I think this fixed it. Mike Christie (talk - contribs - library) 10:49, 11 October 2022 (UTC)
 * You're not consistent on the use of publisher locations in the book citations.
 * Decided to leave them only for conferences. Jo-Jo Eumerus (talk) 09:19, 11 October 2022 (UTC)
 * I see some others still in the book citations -- e.g. Albarede (2011) and Amils (2011). Mike Christie (talk - contribs - library) 10:53, 11 October 2022 (UTC)
 * I don't see any locations there? Jo-Jo Eumerus (talk) 12:36, 11 October 2022 (UTC)
 * My mistake; I was looking at the wrong thing. Mike Christie (talk - contribs - library) 14:13, 11 October 2022 (UTC)
 * The web citations aren't consistently formatted. Weisstein has no website/work parameter, and FN 14 and 31 add what seems unnecessary disambiguation; and the publisher is given for two of the four web citations but not the other two.
 * Resolved, but left the disambiguators in since they are equivalent to a pagenumber here. Jo-Jo Eumerus (talk) 09:19, 11 October 2022 (UTC)
 * In checking this I found this page, which makes me think the website should be given as "Eric Weisstein's World of Science" rather than the URL, though I do see that they brand it that way on the entries. I was initially concerned this was a one-man operation and public submissions of content but looking through the FAQ it appears to have corporate ownership and editorial control. Mike Christie (talk - contribs -  library) 11:01, 11 October 2022 (UTC)
 * You give the publisher for a handful of the journal and report citations -- any reason for doing so in those cases only?
 * I think they are more important for books and reports; changed it in others. Jo-Jo Eumerus (talk) 09:19, 11 October 2022 (UTC)
 * One publisher left on Fidrick (2020). Mike Christie (talk - contribs - library) 11:03, 11 October 2022 (UTC)
 * Done. Jo-Jo Eumerus (talk) 12:36, 11 October 2022 (UTC)
 * Rinaldi et al. (2017) has "www.ceps.eu" as the website; should this just be "CEPS"?
 * Yes; done. Jo-Jo Eumerus (talk) 09:19, 11 October 2022 (UTC)

Sources are reliable as far as I can tell, not being knowledgeable about this field. The arXiv links are popping up as alerts but it seems they're just a URL for the text of the papers, not the actual source cited, so that's fine. Other than as noted above, the links all work. Mike Christie (talk - contribs - library) 22:25, 10 October 2022 (UTC)
 * Shouldn't Gillon et al. sort after Gillon?
 * The link to Gillon, Meadows, et al. (2020) is broken.
 * I think I solved both. Jo-Jo Eumerus (talk) 09:19, 11 October 2022 (UTC)
 * Gillon & Triaud is now sorting before Gillon & Meadows; this is chronological but I usually see this sorted by second author before date. Mike Christie (talk - contribs - library) 10:49, 11 October 2022 (UTC)
 * I think the sorting order here is first author-date-second author. Jo-Jo Eumerus (talk) 12:36, 11 October 2022 (UTC)
 * Lingam & Loeb (2018) is listed out of alphabetical order in the sources, between Quick and Radnóti. And why is it 2018c?  There doesn't seem to be any risk of confusion with the other sources.
 * Problem is that Lingam and Loeb published two other papers in 2018 that are cited here. Moved it back to order. Jo-Jo Eumerus (talk) 09:19, 11 October 2022 (UTC)
 * Then for consistency wouldn't you want 2018a and 2018b on the others? I also just noticed that Lingam & Loeb 2019 has no disambiguator in the source list but does in the citations. Mike Christie (talk - contribs -  library) 10:49, 11 October 2022 (UTC)
 * Changed so that the disambiguator is only used in the source list; 2018a is not a date, after all. Jo-Jo Eumerus (talk) 12:36, 11 October 2022 (UTC)

The only issue left is that I think the Wolfram site's website parameter should be ""Eric Weisstein's World of Science". Mike Christie (talk - contribs - library) 15:11, 11 October 2022 (UTC)
 * Done. Jo-Jo Eumerus (talk) 08:53, 12 October 2022 (UTC)
 * Pass. Mike Christie (talk - contribs - library) 09:10, 12 October 2022 (UTC)

Support by CactiStaccingCrane
Support - content-wise and image-wise, the article is top-notch. Bad content and good layout/prose is much worse than good content and bad layout/prose. People are just nit-picking entropy at this point. CactiStaccingCrane (talk) 16:02, 17 October 2022 (UTC)


 * I know that this can be an controversial opinion, so let me detail at what I meant:
 * This article's sourcing is really solid. The author did the right thing by citing the research papers directly instead of citing newspapers. And as Mike Christie's source check shows, there is little if any issue at source-text integrity.
 * The article's prose is also good and reasonably easy to understand. Yes, some jargons need to be explained, some need to be clarified, and some should be substituted by other terms instead. But this should not a deal-breaker for FAC. The prose reviewing effort should be redirected towards WP:URFAs instead, where they are desperately needing more people to repolish old FAs.
 * CactiStaccingCrane (talk) 16:13, 17 October 2022 (UTC)
 * Coordinator note: hi Mike, could I just check whether your source review confirms "there is little if any issue at source-text integrity"? Thanks.
 * Also, without prejudicing any closure decision, the FAC criteria do not require a nomination to be "reasonably easy to understand", and I fail to understand how a review which notes "some jargons need to be explained, some need to be clarified, and some should be substituted by other terms instead" can conclude "this should not a deal-breaker for FAC." The desire to see limited reviewing resources directed to venues other that FAC is not a sufficient reason to support an FAC nomination if the FAC criteria are not met. Gog the Mild (talk) 13:17, 19 October 2022 (UTC)
 * , I did no spotchecking so I can't comment either way on the source-text integrity. If you feel a spotcheck is needed I can try to find time to do one but it might be as well to list it at the usual place in case someone else can get to it; I wasn't planning to do any reviewing for a few days. Mike Christie (talk - contribs -  library) 21:36, 19 October 2022 (UTC)

Oppose from Gog the Mild
Recusing to review.

Looking at the lead:


 * "The star itself was discovered". Delete "itself", what else would it be?
 * "The gravity of TRAPPIST-1's neighbouring planets". What does "neighbouring" mean? If what I am guessing then perhaps best to delete it.
 * "As many as four of the planets". Delete "As many as".
 * "an atmosphere, a precondition for life". Really?! And this is the clear consensus of the scholarly sources? Additionally, I do not see this repeated in the article.
 * I note some good uses of in line explanation, per general good practice and MOS:NOFORCELINK. ("Do use a link wherever appropriate, but as far as possible do not force a reader to use that link to understand the sentence. The text needs to make sense to readers who cannot follow links.")

Jumping to "Potential atmospheres".


 * "The existence of atmospheres around TRAPPIST-1 planets is a function of the balance between the decay of such an atmosphere, the amount of atmosphere initially present and the rate at which it is reconstituted by impact events,[76] accretion from a protoplanetary disk[180] and outgassing/volcanic activity.[181] Impact events would be particularly important in the outer planets, as impact events can both add and remove volatiles from the planets; in the outermost planets addition is likely dominant." This prose becomes increasingly impenetrable to a non-expert reader.
 * "including oceans over hundred times larger than Earth's". Either 'a hundred' or 'one hundred'.
 * "If the planets are tidally locked to TRAPPIST-1 and one side of their surface always faces away from the star". It is not a case of "and". 'with' or ', meaning that' would be better.
 * "In the case of a carbon dioxide atmosphere, the burial of carbon dioxide ice under water ice, driven by the density of carbon dioxide ice, the formation of carbon dioxide-water compounds named clathrates[z] and a potential runaway feedback loop between ice melting and evaporation and the greenhouse effect additionally complicate matters.[188]" Beautifully expressed, but not at the appropriate level (IMO) for a general encyclopedia article.
 * "have ruled out that the TRAPPIST-1 planets have hydrogen- or helium-rich atmospheres". Grammar: perhaps 'have ruled out the possibility that the TRAPPIST-1 planets have hydrogen- or helium-rich atmospheres' or similar.
 * "The existence of such an atmosphere and its mass are a function of the initial water mass, by whether the oxygen is dragged out of the atmosphere by escaping hydrogen and by the state of the planet's surface; a partially molten surface could absorb large quantities of oxygen, sufficient to remove an atmosphere." I think that most instances of "by" should be 'of'.
 * "as they are destroyed by the radiation of the star". "are → 'would be'.
 * "Biogenic ammonia or methane production would have to be considerably larger than on Earth to sustain such an atmosphere. It is however possible that the development of organic hazes from ammonia/methane photolysis could shield the remaining molecules." I doubt that a general reader would make much of this. As a minimum it needs an explanation of "Biogenic ammonia or methane production".
 * "Radiative decomposition of carbon dioxide could yield substantial amounts of oxygen, carbon monoxide[203] and ozone." no doubt, whatever "radiative decomposition" might be.

I am full of admiration for this article, in many ways it is excellent. However, in spite of the large amount of work since the article was nominated, the prose still has deficiencies and large parts of it do not seem to do what a Wikipedia aricle is supposed to: explain the topic at the level of a general reader. I appreciated it so much that I want to support it, but objectively I just don't think that it - yet - meets the criteria and so am reluctantly opposing. Gog the Mild (talk) 14:07, 27 October 2022 (UTC)

Coordinator note (2) -- this is a very long-running nom and unfortunately we're not getting closer to consensus as things go on so I'm pulling the plug; I realise there was a PR before the FAC but at the very least I'd suggest an informal review by some of the above commentators, especially the opposing ones, before any future run at FAC following the usual two-week break. Cheers, Ian Rose (talk) 14:24, 27 October 2022 (UTC)

Hog Farm Talk 03:59, 28 October 2022 (UTC)