Talk:TRAPPIST-1/Archive 2

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Archive 1 Archive 2

Pre-FAC review

Per Jo-Jo's request, I'll post review comments here with the aim of getting the article ready for another run at FAC. I'll add comments as I have time to go through the article.

  • "its planets were discovered in 2016 and 2017 based on observations from the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) at La Silla Observatory in Chile and numerous other telescopes. Following the initial discovery of two terrestrial planets in orbit around TRAPPIST-1, a data "anomaly" was found to be caused by five more planets." The anomaly here is just the light-curve data, right? I'm not sure we want to use "anomaly" for that in the lead, and why use scare quotes? I think it would make more sense to say that the data was initially interpreted as indicating three planets, but further analysis revealed that there were seven.
    That's done. Jo-Jo Eumerus (talk) 09:14, 26 March 2023 (UTC)
    I think we should focus more on what was discovered. How about "The star was discovered in 1999. In 2016 observations from the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) at La Silla Observatory in Chile and numerous other telescopes led to the discovery of two terrestrial planets in orbit around the star, and in 2017 further analysis of the light curve identified five more planets." Mike Christie (talk - contribs - library) 11:59, 27 March 2023 (UTC)
    That sounds better; I've put it in. Jo-Jo Eumerus (talk) 08:14, 28 March 2023 (UTC)
  • Suggest moving the rather alphabet-soup list of alternative names for the star to footnote e to join the comment about SPECULOOS, unless any of these names are important for some reason.
    Hrmm. Given the importance of such names to database searches, I am actually inclined to leave them in the text. Jo-Jo Eumerus (talk) 09:14, 26 March 2023 (UTC)
    Could the list of designations be put in the infobox, using Template:Starbox catalog? That's what's done on most star articles. SevenSpheres (talk) 15:27, 26 March 2023 (UTC)
    You sure that that is the right template? But upon thinking, a footnote might work too. Jo-Jo Eumerus (talk) 17:18, 26 March 2023 (UTC)
    The infobox would be better, but I think it's important to get them out of the text. Mike Christie (talk - contribs - library) 11:59, 27 March 2023 (UTC)
    Well, what do you know, I had forgotten that there was a commented-out Starbox catalog template here. I've put them there. Jo-Jo Eumerus (talk) 08:14, 28 March 2023 (UTC)
  • "TRAPPIST-1 is a very close star, parallax measurements have yielded a distance of 40.662 ± 0.036 light-years (12.467 ± 0.011 pc) from the Solar System, and has a large proper motion. There is no evidence that TRAPPIST-1 has companion stars." This is a good example of what I think needs to be done in a copyedit. The conversion to parsecs isn't really necessary, given that a scientist would understand either measurement and a lay-person won't be that familiar with either. Five significant figures is too many for the text. The infobox has the conversion, and only gives four sig figs; I would suggest that's fine for the text too. I don't think we need to say parallax is how the distance was determined -- unless I've forgotten what astrophysics I know, that's how all nearby star distances are determined, so it's not an interesting fact about this star. And the source for the last sentence says it has conclusively eliminated the possibility of companion stars. So I think this could be "TRAPPIST-1 is a very close star, at 40.66 ± 0.04 light-years away, with a large proper motion. It has no companion stars."
    Did that rewrite. Jo-Jo Eumerus (talk) 09:14, 26 March 2023 (UTC)
  • I imagine some of the lettered footnotes are the result of FAC comments asking for inline explanations. I think this can go too far. See the last few comments in this discussion; the example by NebY is how this reads to me, as someone with a (minor) background in the topic. I'm not going to suggest you remove any of them, but I think you do have more than you really need.
    Actually, I did put many of the footnotes there myself. But yes, some people like to have the terms explained in the article. Others are satisfied with links. I don't think I've seen much of a consensus on what's better. Jo-Jo Eumerus (talk) 09:14, 26 March 2023 (UTC)
  • "TRAPPIST-1 is a red dwarf,[30] a cold star with a smaller mass than the Sun. Red dwarfs include the spectral types[h] M and K,[32] and TRAPPIST-1 belongs to class M8.0±0.5.[33] Its mass is about 8.98% of the Sun's mass,[34] only barely sufficient mass to allow nuclear fusion to take place.[35][36] Its radius is 11.9% that of the Sun, making the star slightly larger than Jupiter.[33] While denser than the Sun,[33] TRAPPIST-1 has an unusually low density for its kind of star.[37] Its luminosity is only about 0.055% that of the Sun[34] and is mostly infrared light;[38] it is not variable[33] and there is no evidence for a solar cycle.[39] TRAPPIST-1 has an effective temperature[i] of 2,566 K (2,293 °C; 4,159 °F),[5] making it the coldest known star (as of 2022) to host planets.[41]" Suggest "TRAPPIST-1 is a red dwarf with spectral class M8.0±0.5, meaning that it is small and cold. Its radius is about 12% of the Sun's radius, and its mass is about 9% of the Sun's, which is barely sufficient to allow nuclear fusion to take place. Hence it has a low effective temperature of 2,566 K, making it the coldest known star (as of 2022) to host planets. TRAPPIST-1's density is unusually low for a red dwarf, and it has a luminosity of about 0.055% that of the Sun, consisting mostly of infrared light. It is not variable and there is no evidence for a solar cycle." I would argue against converting a temperature in K in a scientific article.
    I distinctly remember that some people wanted an explanation of "red dwarf", so I left that in. I think Dwarf stars like TRAPPIST-1 are over ten times more common than Sun-like stars[1] and these stars are more likely to host small planets than Sun-like stars.[2] The known planetary systems around ultracold stars contain multiple planets,[3] but it is unclear how many such stars feature planets.[4] is useful "putting into context information", myself. Jo-Jo Eumerus (talk) 09:14, 26 March 2023 (UTC)
    The "as of" has a capital "A"; presumably this is controlled by a template? Mike Christie (talk - contribs - library) 11:59, 27 March 2023 (UTC)
    Yes; fixed that. Jo-Jo Eumerus (talk) 08:14, 28 March 2023 (UTC)

References

  1. ^ Lingam & Loeb 2019a, p. 15.
  2. ^ Delrez et al. 2018, p. 3578.
  3. ^ Delrez et al. 2022, p. 21.
  4. ^ Huang & Ormel 2022, p. 3814.
  • "Stars like TRAPPIST-1 are so cold that clouds consisting of condensates and dust can form in their photosphere.[45] Patterns of TRAPPIST-1's radiation indicate the existence of dust, which is distributed evenly across the star's surface." The source is careful to make it clear that this is not the standard definition of "dust" or "cloud"; to avoid having to do further explanations inline I would suggest avoiding both of these words. These two sentence say "Stars like this can have X; this star has X". I think this is unnecessarily wordy; how about "TRAPPIST-1 is cold enough for condensates to form in its photosphere, which have been detected by a polarimetric analysis of its radiation during transits of its planets."
    That's certainly better, but now I worry folks will want to know what "polarimetric" means. Jo-Jo Eumerus (talk) 09:14, 26 March 2023 (UTC)
    Yes, it's possible. I would suggest not adding a footnote though -- as I said above, I think there are too many already. Mike Christie (talk - contribs - library) 11:59, 27 March 2023 (UTC)
    In that case, the rewrite is in. Jo-Jo Eumerus (talk) 08:14, 28 March 2023 (UTC)

Pausing here to make sure this feedback is useful; let me know what you think about these suggestions. Mike Christie (talk - contribs - library) 13:52, 25 March 2023 (UTC)

Rotation period and age

  • "As of 2020, discrepancies between rotational data obtained by the Spitzer Space Telescope and Kepler space telescope remain unexplained". Is this based on the word "putative" in Ducrot? If so I don't think that's enough.
    Sort of; there is a disagreement also mentioned by Miles-Páez et al. (2019) and I don't think it's ever been conclusively agreed on why there is that discrepancy. Jo-Jo Eumerus (talk) 09:06, 31 March 2023 (UTC)
    There is a bit of discussion at arXiv:1711.02676 but I don't think it settled the question. Jo-Jo Eumerus (talk) 14:49, 31 March 2023 (UTC)
    I think that's more citable than the original papers. As far as I can see it gives the 1.40 and 3.30 day periods, suggests a mechanism for the discrepancy (p. 3 of the arXiv pdf), and ends up supporting the K2 rate, citing other work casting doubt on the reliability of photometric determination of rotation rates for M dwarfs. I would cite this instead of the earlier two papers; it gives all the necessary details and as a review of the earlier data is a better source (and citing it will have the side benefit of removing some of the ugly mid-sentence footnotes). Mike Christie (talk - contribs - library) 10:59, 3 April 2023 (UTC)
    Applied a rewrite, but I think its wording can be improved. Jo-Jo Eumerus (talk) 14:15, 3 April 2023 (UTC)
  • "The rotation axis of TRAPPIST-1 might be slightly offset from that of its planets." The source gives no more details than this, but cites Hirano, T., Krishnamurthy, V., Gaidos, E., et al. 2020b, ApJL, 899, L13. Do you have access to this?
    Yes, and they mixed their references up - Hirano 2020b is about Pi Mensae not TRAPPIST-1 - it's instead Hirano 2020a arXiv:2002.05892. It doesn't have much information beyond that the offset isn't large, and also mentions the rotation period discrepancy. Jo-Jo Eumerus (talk) 09:06, 31 March 2023 (UTC)
  • I'm trying to pull up the papers cited for the rotation section, but for FN 33, Gillon/Jehin/ et al., I get a PDS with pages numbered 1-38 via arXiv, and with pages number 1-26 via ncbi.nlm.nih.gov. The pages given in the source citation are 221-224 in Nature, and the footnote says p. 221. I don't know how you can resolve this, but I think the reader has to have a way to find the page you're citing. Similarly for the next citation you give p. 4025 but the PDF on arXiv has no similar numbering.
    Yeah, I by default use the original source (linked through the DOI) and never the arXiv. Jo-Jo Eumerus (talk) 09:06, 31 March 2023 (UTC)
  • Assuming I've found the right source text, what FN 45 says is "The short rotation period of TRAPPIST-1 is typical among the subset of late M dwarfs which are rapidly rotating" which is not quite the same as "typical period for M dwarfs", which is what you have in the article. Given the qualification, I'm not sure this is useful; as far as I can tell the paper is talking about what M dwarfs are suitable for a particularly observational technique, and not making a general statement about M dwarfs.
    Would it more useful if it did specify late M dwarfs? Jo-Jo Eumerus (talk) 09:06, 31 March 2023 (UTC)
    Fixed by someone else. Mike Christie (talk - contribs - library) 10:59, 3 April 2023 (UTC)

More to come; still reading the papers for this section. Mike Christie (talk - contribs - library) 23:06, 30 March 2023 (UTC)

  • "TRAPPIST-1 is a red dwarf[h][31] with spectral class[i] M8.0±0.5,[33] meaning that it is small and cold." I know this has come up in your FACs before; citing short phrases within a sentence is technically accurate but very distracting for a reader. I think this is harmless for longer sentences -- e.g. "Weird Tales' subtitle was "The Unique Magazine", and Wright's story selections were as varied as the subtitle promised;[3] he was willing to print strange or bizarre stories with no hint of the fantastic if they were unusual enough to fit in the magazine.[76]" from an article I wrote -- but when the density of footnotes approaches that of the text it really impacts the reader experience. I would suggest moving both the footnotes and explanatory notes to the end where the sentence is reasonably short -- here that would look like "TRAPPIST-1 is a red dwarf with spectral class M8.0±0.5, meaning that it is small and cold.[h][31][33]", with [h] including explanations of both "red dwarf" and "spectral class".

-- Mike Christie (talk - contribs - library) 10:59, 3 April 2023 (UTC)

Activity

I've done some edits here, one thing I wonder is whether the flares thing from the atmospheric stability section would be better off here. Jo-Jo Eumerus (talk) 09:43, 26 April 2023 (UTC)

Comment

Hi Jo-Jo Eumerus, I have lost track of where the previous conversation was posted, so this is a reminder that I am happy, RL and WP commitments permitting, to copy edit this if and when you would like me to. Gog the Mild (talk) 18:57, 10 May 2023 (UTC)

Greetings, Gog the Mild, it was originally on my talk page. Yes, I would appreciate such a copyedit, as folks have noted there are still prose issues and I don't trust myself to find them all. Jo-Jo Eumerus (talk) 08:28, 11 May 2023 (UTC)
I shall get started. Feel free to revert anything. I won't care and won't be watchlisting. Feel free to query here anything you don't understand. Similarly I shall post any queries here. Gog the Mild (talk) 14:35, 15 May 2023 (UTC)
Copy edit queries
  • "The star has a strong magnetic field[61] with a mean intensity of about 600 gauss." Is there anything which a reader may be familiar with which could be used as a comparator, to give some context?
  • "TRAPPIST-1 is orbited by seven planets". You are entirely confident that this doesn't need to be 'seven known planets' or 'at least seven planets'?

Gog the Mild (talk) 15:04, 15 May 2023 (UTC)

Orders of magnitude (magnetic field) shows Earth's magnetic field at about 1/1000th and a refrigerator's at slightly less than one tenth. I'll need to check for sources to use. Yes, I think everybody currently assumes it's only 7 planets. There was a sentence before about the properties of a hypothetical 8th planet but editors thought it was superfluous. Jo-Jo Eumerus (talk) 16:17, 15 May 2023 (UTC)
  • Any chance of a brief in line explanation of "volatile compound"?
  • "note that heating in the outer planets could be". Is that tidal heating? If so, perhaps say so?
  • "Tidal phenomena can influence the masses of the planets observed from Earth". I don't understand what this means. Gog the Mild (talk) 16:41, 15 May 2023 (UTC)
Think I got these issues resolved. Jo-Jo Eumerus (talk) 07:48, 16 May 2023 (UTC)
  • "Tides can also occur in the planetary atmospheres". Are you talking in general terms or about the TRAPPIST-1 planets? If the latter, perhaps "can" → 'may'?
  • "The lack of giant impacts". Maybe a brief explanation of what causes these/why they might have been expected? Gog the Mild (talk) 12:13, 16 May 2023 (UTC)
    In general terms, for the first. For the second, put a parenthetical in but a better word than "pre-planetary" is probably needed. Jo-Jo Eumerus (talk) 14:41, 16 May 2023 (UTC)
  • "Impact events would be particularly important in the outer planets because they can both add and remove volatiles". So this is not the case for TRAPPIST-1's inner planets?
  • "the planets' formation conditions would give them large initial quantities of volatile materials". Just checking that that "would" shouldn't be a 'could'. Gog the Mild (talk) 16:51, 16 May 2023 (UTC)
    No; impact velocities there are higher; I think that means that more mass is removed than added. It's "would", yes; volatile-poor planets can only form beyond the snowline if the disk has an unphysical chemical composition. Jo-Jo Eumerus (talk) 07:46, 17 May 2023 (UTC)
  • "It is likely too distant from its host star to sustain liquid water, instead forming an entirely glaciated snowball planet. Moderate quantities of CO2 could warm TRAPPIST-1f to temperatures adequate for liquid water to exist." These two consecutive sentences seem to contradict each other. And then "it could thus be an ocean planet". I understand that "could" doesn't overwrite "likely", but it could be written a little more clearly for a lay reader.
  • "is considerably less than that of Earth." I am not sure that this means anything. Surely the chance of life on Earth is 1? Gog the Mild (talk) 15:38, 17 May 2023 (UTC)
    The first is a bit of disagreement between sources - it's unlikely that it has liquid water, and IF it has liquid water, then due to a thick CO2-rich atmosphere. The thing about ocean planets is that they don't have to have surface water - even if TRAPPIST-1f has no surface water, it can have an ocean under an ice shell. For the second, it means that based on theoretical considerations, odds of an Earth-like planet developing life are much higher than of a TRAPPIST-1f-like planet developing life. Jo-Jo Eumerus (talk) 15:59, 17 May 2023 (UTC)
  • "The star has been subject of detailed studies of its various aspects, including the possible effects of vegetation ..." I am a bit lost with this sentence. I assume that we are still discussing TRAPPIST-1? It reads as if there may be vegetation on it, or as if vegetation may effect the star - I assume I am misreading somewhere? And "the possibility of the detection of an ocean using starlight reflected off its surface"; starlight reflected off a star - do I have that right?— Preceding unsigned comment added by Gog the Mild (talk • contribs)
    Yes, rewrote that a bit. Jo-Jo Eumerus (talk) 07:31, 18 May 2023 (UTC)
  • "TRAPPIST-1a refers to the star itself". If this is so, what does "TRAPPIST-1" refer to? Gog the Mild (talk) 11:27, 20 May 2023 (UTC)
    TRAPPIST-1a isn't used by itself; it's just an explanation why the alphabetic code begins with "b". I've done a minor rewrite but someone can probably explain it better. Jo-Jo Eumerus (talk) 18:00, 20 May 2023 (UTC)
Second run through (Just skimming)
  • "The lack of giant impacts". A reader still isn't told what this means, nor just what is impacting what.
    Tried to fix the issue. The problem I have here is that there isn't an easily understood term for "smaller-than-planet, larger-than-asteroid" bodies. Jo-Jo Eumerus (talk) 18:00, 20 May 2023 (UTC)
  • "Impact events would be particularly important in the outer planets because they can both add and remove volatiles; addition is likely dominant in the outermost planets where impact velocities are slower." You say "would be" and "is likely" about the same thing in the same sentence. Which is it?
    Done. Jo-Jo Eumerus (talk) 18:00, 20 May 2023 (UTC)

And that is all I have. Good look with the FAC. Gog the Mild (talk) 11:55, 20 May 2023 (UTC)

@Gog the Mild: Thanks. Now only SandyGeorgia's comments are still outstanding. Jo-Jo Eumerus (talk) 18:00, 20 May 2023 (UTC)
Jo-Jo, I should be able to get to this Monday or Tuesday ... should I forget, do not hesitate to poke me on my talk page :) SandyGeorgia (Talk) 12:08, 21 May 2023 (UTC)

SG review

Jo-Jo, so sorry for the delay; I am starting in after breakfast. SandyGeorgia (Talk) 12:50, 3 June 2023 (UTC)

  • I don't know how to fix this; accessibility says not to add images to the bottom of sections, so I moved it up, which displays fine on my iPad and iPhone, but not on my regular computer. Is there another place that image can be used instead? Can it just be moved in to the first section (1b)?
    As in, to the section "TRAPPIST-1b"? No, it would be out of place there. I don't know how to make the image appear in the correct place. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    So, not sure how to fix this ... I guess wait and see what people say at FAC. SandyGeorgia (Talk) 22:28, 4 June 2023 (UTC)
    I've asked for assistance at WP:HD Jo-Jo Eumerus (talk) 08:10, 5 June 2023 (UTC)
    @Jo-Jo Eumerus I've replied there. Feel free to move my comments to here if you need to. Bazza (talk) 09:03, 5 June 2023 (UTC)
    Tried something Jo-Jo Eumerus (talk) 09:21, 5 June 2023 (UTC)
  • Why List of planets instead of just Planets ?
    • On both of the previous points, we have two sections with lists of the planets ... the Planetary system and List of Planets ... can these somehow be merged? Can one of the images be moved to the first section if not? SandyGeorgia (Talk) 14:44, 3 June 2023 (UTC)
      • Re: The image: Probably. As for why two sections - one discusses the planetary system as a whole, the other has a bit more information on the individual planets. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
  • Sometimes notes are before citations, sometimes after ... standardize
    • ... of the celestial equator.[b][17][18] The star was discovered in 1999 by astronomer John Gizis and colleagues;[19] the name is a reference to the TRansiting Planets and PlanetesImals Small Telescope (TRAPPIST)[11][c] project that discovered the first two exoplanets around the star.[23] TRAPPIST-1 is a very close star[24] located at 40.66±0.04 light-years from Earth,[d][17]SandyGeorgia (Talk) 14:19, 3 June 2023 (UTC)
      • Notes are supposed to be after the word they explain. Most times, before the citation. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
  • Why hyphenated ? True-color illustration of the Sun ... SandyGeorgia (Talk) 14:19, 3 June 2023 (UTC)
    I think that's the more common spelling, but don't know if that is true. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Will leave then and see if anyone inquires at FAC. SandyGeorgia (Talk) 22:42, 4 June 2023 (UTC)
  • The star was discovered in 1999 by astronomer John Gizis and colleagues;[19] ... why is this in Description, and not mentioned instead with the rest of the Research history section? SandyGeorgia (Talk) 14:22, 3 June 2023 (UTC)
    Moved it down and merged it with the other mention. Put a footnote to explain my choice of year, but it's a bit OR-ey. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
     Done SandyGeorgia (Talk) 22:42, 4 June 2023 (UTC)
  • With its radius being 12% that of the sun, it is only slightly larger than the planet Jupiter.[30] --> With a radius 12% of that of the sun, it is only ... SandyGeorgia (Talk) 14:44, 3 June 2023 (UTC)
    Done. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
     Done SandyGeorgia (Talk) 22:42, 4 June 2023 (UTC)
  • Should luminosity be linked? SandyGeorgia (Talk) 14:44, 3 June 2023 (UTC)
    I dunno, this seems quite basic? Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Since we have an article, won't hurt for novices (like me) ... linked. SandyGeorgia (Talk) 22:42, 4 June 2023 (UTC)
  • The Kepler and Spitzer Space Telescopes have observed possible bright spots, which may be faculae,[k][55][56] although some of these may be too large.[57] Too large for what? SandyGeorgia (Talk) 14:44, 3 June 2023 (UTC)
    Explained. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Much better! SandyGeorgia (Talk) 22:42, 4 June 2023 (UTC)
  • New paragraph here ? The star has a strong magnetic field ... SandyGeorgia (Talk) 14:44, 3 June 2023 (UTC)
    Done. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
     Done SandyGeorgia (Talk) 22:42, 4 June 2023 (UTC)
  • Three instances so far of stray punctuation; check throughout ? SandyGeorgia (Talk) 14:44, 3 June 2023 (UTC)
    Done, didn't find anything. Jo-Jo Eumerus (talk) 07:30, 4 June 2023 (UTC)
     Done, think we got them all. SandyGeorgia (Talk) 22:42, 4 June 2023 (UTC)
  • This acronym is never used in the article, could be removed. and may be capable of trapping coronal mass ejections (CMEs) SandyGeorgia (Talk) 14:44, 3 June 2023 (UTC)
    Removed. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
     Done SandyGeorgia (Talk) 22:42, 4 June 2023 (UTC)
  • Complicating matters, as of 2019 most of the parameters Complicating what matters (that is, why is this a problem)? SandyGeorgia (Talk) 14:44, 3 June 2023 (UTC)
    Because inferred values are less reliable. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Jo-Jo Eumerus Ah, I see ... can we say something like this then ?? Dong et al. (2018) simulated the observed properties of TRAPPIST-1 with a mass loss of 4.1×10−15 solar masses per year.[60] Simulations to estimate mass loss are complicated because, as of 2019, most of the parameters that govern TRAPPIST-1's stellar wind are not known from direct observation.[62] SandyGeorgia (Talk) 22:42, 4 June 2023 (UTC)
    Done, but I have to note that the source does not specify which parameters of the stellar wind are hard to estimate. Jo-Jo Eumerus (talk) 08:10, 5 June 2023 (UTC)

Planetary system

  • Link astronomical unit on first occurrence ?
    Done. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Changed to link= on to get it inline. SandyGeorgia (Talk) 23:00, 4 June 2023 (UTC)
  • I can't decipher why this comma ? The TRAPPIST-1 planets are expected to have similar compositions, resembling Earth's. SandyGeorgia (Talk) 14:55, 3 June 2023 (UTC)
    Without the comma, it's less clear that the planets resemble each other and not just Earth. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Does this work ? [1] (typo fixed in next edit)? SandyGeorgia (Talk) 23:00, 4 June 2023 (UTC)
    That is better. Jo-Jo Eumerus (talk) 08:10, 5 June 2023 (UTC)
  • Why this hyphen? Because the planets are most-likely synchronized to their host star, SandyGeorgia (Talk) 15:03, 3 June 2023 (UTC)
    Typo, I think. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Done, SandyGeorgia (Talk) 23:00, 4 June 2023 (UTC)
  • the greenhouse effect of water-vapour atmospheres ... not sure what water-vapour atmospheres are, but if it is water to vapour, it should use an WP:ENDASH rather than a hyphen.
    Atmospheres consisting of water vapour. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Removed hyphen, SandyGeorgia (Talk) 23:00, 4 June 2023 (UTC)
  • Can this snake be chopped in two? Due to a combination of high insolation, the greenhouse effect of water-vapour atmospheres and remnant heat from the process of planet assembly, the TRAPPIST-1 planets would likely initially have had molten surfaces, which would have cooled until the magma oceans solidified, which may have taken between a few billions of years, or a few millions of years in the case of TRAPPIST-1b. SandyGeorgia (Talk) 15:03, 3 June 2023 (UTC)
    Done. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Better! SandyGeorgia (Talk) 23:00, 4 June 2023 (UTC)

Potential planetary atmospheres

  • Because the visibility of an exoplanet and of its atmosphere scale with the inverse square of the radius of its host star, atmospheres could be detected in the future. Why (do we expect the radius of the host to change over time)?? SandyGeorgia (Talk) 15:17, 3 June 2023 (UTC)
    This needs a bigger rewrite; it means that detection should be easier than around other stars, but that has nothing to do with a detection being in the future. At the moment, I dunno how to formulate. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Did a rewrite. Jo-Jo Eumerus (talk) 07:30, 4 June 2023 (UTC)
     Done SandyGeorgia (Talk) 23:09, 4 June 2023 (UTC)
  • A contamination of the atmospheric signals through patterns in the stellar photosphere is an additional problem.[189] Problemm in what ?? Impediment to detection? SandyGeorgia (Talk) 15:17, 3 June 2023 (UTC)
    Yes, because then you aren't sure if the signal is from the atmosphere or from the star. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Changed, SandyGeorgia (Talk) 23:09, 4 June 2023 (UTC)
  • Can this be split and differently punctuated (lot going on there): In a carbon dioxide (CO2) atmosphere, carbon-dioxide ice is denser than water ice, under which it tends to be buried; CO2-water compounds named clathrates[ad] can form; these processes may be complicated by a potential runaway feedback loop between melting ice and evaporation, and the greenhouse effect.[198]
    Done. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
     Done, better! SandyGeorgia (Talk) 23:09, 4 June 2023 (UTC)
  • Theoretical modelling by Krissansen-Totton and Fortney ... Isn't all modelling theoretical ?
    Sometimes models are based on primary evidence, then they are less theoretical. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    OK, SandyGeorgia (Talk) 23:09, 4 June 2023 (UTC)
  • M dwarfs emit large amounts of XUV radiation;[218] first occurrence of the term M dwarf ... what is it? SandyGeorgia (Talk) 15:17, 3 June 2023 (UTC)
    Explained. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    not done Still unclear. Jo-Jo Eumerus, the term M dwarf is not used before this in the article, and is not linked. M dwarf goes to Red dwarf; this article uses the term Red dwarf. The red dwarf article tells me that definitions vary, so M dwarfs and Red dwarfs aren't necessarily the same thing. But we still have to resolve here that we have introduced a new term without telling the reader what it is, or linking it. Can it just link to red dwarf, even if that results in a duplicate link? Duplicate links can sometimes be used ... SandyGeorgia (Talk) 23:16, 4 June 2023 (UTC)
    Does it work better now? Jo-Jo Eumerus (talk) 08:10, 5 June 2023 (UTC)
    That works (the double link is defensible there). SandyGeorgia (Talk) 11:37, 5 June 2023 (UTC)
  • Why hyphenated ? they receive much-more-intense irradiation.
    I dunno, backed it out. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Curious lot of excess hyphenation,  Done. SandyGeorgia (Talk) 23:16, 4 June 2023 (UTC)
  • Why is modelling first linked here ? The process of atmospheric escape has been modelled mainly
    Moved the link up. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    OK, SandyGeorgia (Talk) 23:20, 4 June 2023 (UTC)
  • Why the hyphens? TRAPPIST-1 is moderately-to-highly active, SandyGeorgia (Talk) 15:17, 3 June 2023 (UTC)
    I don't know if they are needed here. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Removed, excess hyphenation again. SandyGeorgia (Talk) 23:20, 4 June 2023 (UTC)

List of planets

  • Down here, we find astronomical units linked for the first time (it was used earlier): TRAPPIST-1b has an average distance from its star of 0.0115 astronomical units
    There is a link farther up now. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
     Done SandyGeorgia (Talk) 23:23, 4 June 2023 (UTC)
  • Something amiss: TRAPPIST-1b has a slightly larger measured diameter and mass than Earth but estimates of its density estimates
    Took a word out. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
     Done SandyGeorgia (Talk) 23:23, 4 June 2023 (UTC)
  • TRAPPIST-1d ... two consecutive sentences start with "Based on ... "
    Rewritten. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Was still there; how's this? SandyGeorgia (Talk) 23:23, 4 June 2023 (UTC)
    Yes, that's better. Jo-Jo Eumerus (talk) 08:10, 5 June 2023 (UTC)
  • It is expected to have been in the habitable zone for a long time ... what is a long time ??
    not done (missed this one)? SandyGeorgia (Talk) 23:29, 4 June 2023 (UTC)
    The problem is that this source does not specify what "long time" means. And upon rereading, I am not sure if it supports the claim at all; removed it. Jo-Jo Eumerus (talk) 08:10, 5 June 2023 (UTC)
    OK< SandyGeorgia (Talk) 11:37, 5 June 2023 (UTC)
  • TRAPPIST-1e could have retained up to several Earth ocean masses of water I suspect this means ... ?? ... TRAPPIST-1e could have masses of water equivalent to several of Earth's oceans  ?? This occurs in several places. If there is such a thing as an Earth-ocean mass of water, it would seem to be asking for a hyphen or some such. SandyGeorgia (Talk) 15:37, 3 June 2023 (UTC)
    Yes, that's what it means. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    OK, in that case, I changed them to that, since "earth ocean masses" is odd. SandyGeorgia (Talk) 23:29, 4 June 2023 (UTC)
  • Statements like this are frustrating ... what is the significance ... ?? Models of tidal effects on TRAPPIST-1e have been created.[255] SandyGeorgia (Talk) 15:37, 3 June 2023 (UTC)
    It's information for a somewhat more specialized audience. But we might move it to the subarticles. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    not done Jo-Jo Eumerus could we either add some information about what these models have shown or why they are signficant, else move to sub-article as you suggest? SandyGeorgia (Talk) 23:30, 4 June 2023 (UTC)
    Removed it. Jo-Jo Eumerus (talk) 08:10, 5 June 2023 (UTC)
    Ok, SandyGeorgia (Talk) 11:37, 5 June 2023 (UTC)
  • density estimates of the planet, if confirmed, indicate it is not dense enough to consist solely of rock. --> estimates indicate it is not dense enough to consist solely of rock. SandyGeorgia (Talk) 15:37, 3 June 2023 (UTC)
    Done. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
     Done SandyGeorgia (Talk) 23:31, 4 June 2023 (UTC)
  • Sometimes AU is abbreviated, other times spelled out ... consistency ... TRAPPIST-1h has a semi-major axis of 0.062 astronomical units SandyGeorgia (Talk) 15:37, 3 June 2023 (UTC)
    Moved it up. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
     Done SandyGeorgia (Talk) 23:31, 4 June 2023 (UTC)
  • Why the hyphen system's least-massive planet ? SandyGeorgia (Talk) 15:37, 3 June 2023 (UTC)
    Took it out. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
     Done SandyGeorgia (Talk) 23:31, 4 June 2023 (UTC)
  • Is the liquid needed here ? temperatures adequate for liquid water to exist. SandyGeorgia (Talk) 15:37, 3 June 2023 (UTC)
    Yes, water can also be ice or steam, an important distinction for habitability. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    OK, SandyGeorgia (Talk) 23:31, 4 June 2023 (UTC)

Possible life

  • Unnecessarily convoluted ?? According to theoretical estimates, on the basis of atmospheric stability, the probability of TRAPPIST-1e, the planet considered most likely to harbour life, actually doing so is considerably less than that of Earth --> On the basis of atmospheric stability, TRAPPIST-1e is theoretically the planet considered most likely to harbour life; the probability that it does is considerably less than that of Earth. SandyGeorgia (Talk) 15:42, 3 June 2023 (UTC)
    That's better; I've put it in. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    Tweaked my rephrase a bit, SandyGeorgia (Talk) 23:34, 4 June 2023 (UTC)
    That's fine. Jo-Jo Eumerus (talk) 08:10, 5 June 2023 (UTC)
Research history and reception
  • See comment above re Gizis and colleagues. SandyGeorgia (Talk) 15:56, 3 June 2023 (UTC)
     Done SandyGeorgia (Talk) 23:34, 4 June 2023 (UTC)
  • Confusing construct, as always, feel free to revert anything I do; [2] SandyGeorgia (Talk) 15:56, 3 June 2023 (UTC)
  • Why the hyphen? are considered among the most-important research findings SandyGeorgia (Talk) 15:56, 3 June 2023 (UTC)
    Beats me; I've taken it out. Jo-Jo Eumerus (talk) 19:52, 3 June 2023 (UTC)
    I'm curious to know where all the hyphens came from :) SandyGeorgia (Talk) 23:34, 4 June 2023 (UTC)

Lead

My suggestions:

Current Suggestions
TRAPPIST-1 is a cold dwarf star, with a surface temperature of about 2,566 K (2,293 °C; 4,159 °F), in the constellation Aquarius. It has a planetary system of seven known planets. TRAPPIST-1 is slightly larger than Jupiter and has a mass of about 9% of that of the Sun. Located 40.7 light-years (12.47 parsecs) away it is estimated to be 7.6 billion years old, making it older than the Solar System.

It was discovered in 2000. Observations in 2016 from the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) at La Silla Observatory in Chile and numerous other telescopes led to the discovery of two terrestrial planets in orbit around TRAPPIST-1. In 2017, further analysis of the original observations identified five more planets. These seven planets take between about 1.5 days and 19 days to orbit around the star. The planets are likely tidally locked to TRAPPIST-1, which would mean that one side of each planet permanently faced the star, leading to permanent day on one side and permanent night on the other.

As many as four of the planets – designated d, e, f and g – orbit at distances where temperatures are suitable for the existence of liquid water, and are thus potentially hospitable to life. There is no evidence any of the planets have an atmosphere and it is unclear whether they could retain one, due to radiation emission from TRAPPIST-1. The planets have low densities; they may consist of large amounts of volatile materials. 		TRAPPIST-1 is a cold dwarf star in the constellation Aquarius, with a surface temperature of about 2,566 K (2,293 °C; 4,159 °F). Discovered in 2000, it is slightly larger than Jupiter and has a mass of about 9% of that of the Sun. Located 40.7 light-years (12.47 parsecs) from the Sun, it is estimated to be 7.6 billion years old, making it older than the Solar System.

The star has a planetary system of seven known planets. Observations in 2016 from the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) at La Silla Observatory in Chile and numerous other telescopes led to the discovery of two terrestrial planets in orbit around TRAPPIST-1. In 2017, further analysis of the original observations identified five more planets. These seven planets take between about 1.5 days and 19 days to orbit around the star. The planets are likely tidally locked to TRAPPIST-1, such that one side of each planet always faces the star, leading to permanent day on one side and permanent night on the other.

As many as four of the planets – designated d, e, f and g – orbit at distances where temperatures are suitable for the existence of liquid water, and are thus potentially hospitable to life. There is no evidence of an atmosphere on any of the planets and it is unclear whether radiation emissions from TRAPPIST-1 would allow for one. The planets have low densities; they may consist of large amounts of volatile materials.

Done; so sorry again for the delay. Revert any damage I did, and ignore anything stupid :) Bst, SandyGeorgia (Talk) 16:14, 3 June 2023 (UTC)

Yeah, that seems OK; swapped it in. Jo-Jo Eumerus (talk) 07:30, 4 June 2023 (UTC)
Jo-Jo Eumerus there are a few stragglers above that may have been missed; otherwise, looks FAC ready to me! Kudos for hanging in over such a long haul with this difficult material!! SandyGeorgia (Talk) 23:36, 4 June 2023 (UTC)
PS, here are my cumulative changes from today. SandyGeorgia (Talk) 23:37, 4 June 2023 (UTC)

Jo-Jo Eumerus looks good, good luck at FAC! SandyGeorgia (Talk) 11:37, 5 June 2023 (UTC)

HarvRef errors

(You can install User:Trappist the monk/HarvErrors.js for detecting HarvRef errors): SandyGeorgia (Talk) 12:55, 5 June 2023 (UTC)

  • Landau, Elizabeth (20 February 2018). "10 Things: All About TRAPPIST-1". NASA. Retrieved 7 February 2023. Harv warning: There is no link pointing to this citation. The anchor is named CITEREFLandau2018.
  • Boss, Alan P.; Weinberger, Alycia J.; Keiser, Sandra A.; Astraatmadja, Tri L.; et al. (23 August 2017). "Astrometric Constraints on the Masses of Long-period Gas Giant Planets in the TRAPPIST-1 Planetary System". The Astronomical Journal. 154 (3): 103. arXiv:1708.02200. Bibcode:2017AJ....154..103B. doi:10.3847/1538-3881/aa84b5. S2CID 118912154. Harv warning: There is no link pointing to this citation. The anchor is named CITEREFBossWeinbergerKeiserAstraatmadja2017.
  • Pineda, J. Sebastian; Hallinan, Gregg (24 October 2018). "A Deep Radio Limit for the TRAPPIST-1 System". The Astrophysical Journal. 866 (2): 155. arXiv:1806.00480. Bibcode:2018ApJ...866..155P. doi:10.3847/1538-4357/aae078. S2CID 119209821. Harv warning: There is no link pointing to this citation. The anchor is named CITEREFPinedaHallinan2018.
  • Huang, Shuo; Ormel, Chris W (22 February 2022). "The dynamics of the TRAPPIST-1 system in the context of its formation". Monthly Notices of the Royal Astronomical Society. 511 (3): 3814–3831. doi:10.1093/mnras/stac288. Harv warning: There is no link pointing to this citation. The anchor is named CITEREFHuangOrmel2022.
    Removed some and used others. I wonder if {{sfn|Pineda|Hallinan|2018}}'s point about TRAPPIST-1 having a Sun-like coronal rather than a Jupiter-like auroral emission is worth adding. Jo-Jo Eumerus (talk) 15:19, 5 June 2023 (UTC)

No atmosphere for planet b

NASA's Webb Measures the Temperature of a Rocky Exoplanet; arXiv:2303.14849 SevenSpheres (talk) 15:49, 27 March 2023 (UTC)

Interesting. As per usual, I am inclined to wait until the article is properly published and it's time for the yearly update. Mostly because press releases tend to omit key information and are oversimplified. Jo-Jo Eumerus (talk) 08:14, 28 March 2023 (UTC)
and now a similar result for planet c - Webb Rules Out Thick Carbon Dioxide Atmosphere for Rocky Exoplanet SevenSpheres (talk) 17:11, 19 June 2023 (UTC)

Did you know nomination

The following is an archived discussion of the DYK nomination of the article below. Please do not modify this page. Subsequent comments should be made on the appropriate discussion page (such as this nomination's talk page, the article's talk page or Wikipedia talk:Did you know), unless there is consensus to re-open the discussion at this page. No further edits should be made to this page.

The result was: promoted by BorgQueen (talk) 15:06, 17 April 2023 (UTC)

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Improved to Good Article status by Jo-Jo Eumerus (talk). Self-nominated at 09:39, 16 March 2023 (UTC). Post-promotion hook changes for this nom will be logged at Template talk:Did you know nominations/TRAPPIST-1; consider watching this nomination, if it is successful, until the hook appears on the Main Page.

General: Article is new enough and long enough
Policy: Article is sourced, neutral, and free of copyright problems
Hook: Hook has been verified by provided inline citation
QPQ: Done.

Overall: Valereee (talk) 17:57, 17 March 2023 (UTC)

  • Not finding the term "harmonic chain" in the article. Valereee (talk) 18:03, 17 March 2023 (UTC)
  • I don't know what a harmonic chain is, which I think affects interestingness of the hook. Maybe a link? Valereee (talk) 18:04, 17 March 2023 (UTC)
  • QPQ started; I can AGF on finishing it once we finish up here. Valereee (talk) 18:06, 17 March 2023 (UTC)
    I confess, I used "harmonic" mostly because I don't know a better word to describe a chain of planets whose orbits are in a beautiful mathematical order. Is there a better word? Jo-Jo Eumerus (talk) 08:43, 18 March 2023 (UTC)
    How do reliable sources describe it? Surtsicna (talk) 16:39, 27 March 2023 (UTC)
    This press release uses "harmonic". Jo-Jo Eumerus (talk) 08:17, 28 March 2023 (UTC)
  • I have to respectfully disagree with Valereee here. I don't really think sticking to the "harmonic" angle would be a good idea, at least without alternative options, considering it may be hard to get by people who aren't into astronomy (I'm an astronomy buff myself and I don't know what it means). TRAPPIST-1 is one of the most-studied and most famous exoplanet systems around, so I'd really prefer there to be a wider pool of possible hooks to be proposed here rather than a single option. I won't oppose the harmonic hook being approved or promoted if chosen, but ideally there should be more hook proposals considering the system's importance in astronomy. Narutolovehinata5 (talk · contributions) 13:25, 2 April 2023 (UTC)
Jo-Jo Eumerus, ALT1 would be fine with me. Valereee (talk) 20:50, 9 April 2023 (UTC)
@Valereee: Is there anything missing? QPQ is linked. Jo-Jo Eumerus (talk) 16:11, 16 April 2023 (UTC)
Approving with ALT1, thanks all! Valereee (talk) 11:19, 17 April 2023 (UTC)

Sourcing of the table

The table produced by this edit from Sandbh has its sources a bit spread out. Are we OK or do we want to standardize? Jo-Jo Eumerus (talk) 12:56, 28 August 2023 (UTC)

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