# Talk:Quaoar

This review is transcluded from Talk:50000 Quaoar/GA1. The edit link for this section can be used to add comments to the review.
Reviewer: PhilipTerryGraham (talk · contribs) 03:47, 22 March 2019 (UTC)
Hey there, Nrco0e! I'll be taking my time over the next few days to review this article under the six criteria, but you are more than welcome to respond and act upon my suggestions as the review progresses! It would make things a lot faster and seamless. – PhilipTerryGraham (talk · articles · reviews) 03:47, 22 March 2019 (UTC)
 1. The article is well written

 1.1. In the lead, consider merging all the lines into a single paragraph. None of the three paragraphs of the lead are more than three sentences long, and are far too short to reasonably be their own paragraphs.
 1.2. In the lead, change "and possibly a dwarf planet" to "and a possible dwarf planet"
 1.3. In the lead, change "which is approximately half" to "which is around half", since the word "approximately" is already used in the same sentence, making for an awkward read.
 1.4. In the lead, change "an 80-kilometer sized synchronous minor-planet moon in orbit around Quaoar" to "a synchronous minor-planet moon in orbit around Quaoar, measuring 80 kilometers across," as it is more clear to the reader that 80 kilometers is the measurement across its body, since it is very likely not a spherical object at that scale.
 1.5. In the lead, truncate the second usage of Michael Brown's name, where his discovery of Weywot is described, to simply "Brown".
 1.6. In "Discovery", consider splitting this sentence that talks about two different passages of information, "The discovery of this magnitude 18.5 object, at the time located in the constellation Ophiuchus, was announced on 7 October 2002, at a meeting of the American Astronomical Society.", into two sentences along the lines of, "At the time of discovery, Quaoar was located in the constellation Ophiuchus, at an apparent magnitude of 18.5. Its discovery was formally announced at a meeting of the American Astronomical Society on 7 October 2002."
 1.7. In "Discovery", capitalise "Palomar observatory sky survey" to "Palomar Observatory Sky Survey", as it is a proper name for an observational campaign.
 1.8. In "Name", consider merging the two paragraphs into one as both paragraphs are relatively short.
 1.9. From "size" onwards, the structure of the article is somewhat confusing. Ideally, "Size" should be a subsection of "Physical characteristics", as size is a physical characteristic of an object. My recommendation is to move "Physical characteristics" above "Orbit and rotation", and merge "Size" as a subsection of "Physical characteristics". The "Classification" and "Hit-and-run collision" subsections can then be made into subsections of "Physical characteristics" under "Size".
 1.10. In "Size", move up the table to the top of the subsection. It otherwise looks awkward hanging below the first paragraph.
 1.11. In "Size", the known facts should be placed before the history of how those facts evolved and/or came to be, as to avoid confusion with outdated information. Open the section with a passage along the lines of this: "Quaoar is estimated to be 1,170 km (730 mi) in diameter, and elongated in shape, according to observations of the object's shadow as it occulted an unnamed 16th-magnitude star on 4 May 2011. Quaoar is about as massive as (if somewhat smaller than) Pluto's moon Charon, which is approximately 2.5 times as massive as Orcus. Quaoar is roughly one twelfth the diameter of Earth, one third the diameter of the Moon, and half the size of Pluto." Remove the passages in the section that this new introduction replaces.
 1.11.1. Remove "On 4 May 2011, Quaoar occulted a 16th-magnitude star, which gave 1,170 km (730 mi) as the longest chord and suggested an elongated shape." from the last paragraph and use the "Braga-Ribas-2011" citation to cite the first sentence of the opening paragraph.
 1.11.2. Further concerns about this point have been raised as point 2.12. of this review.
 1.12. In "Size", make "Quaoar was estimated to have a diameter of 1,260 km (780 mi) with an uncertainty of 190 km (120 mi)" the second sentence of the second paragraph, and add ", using Hubble's measurements" for clarification.
 1.13. In "Size", remove references to "HST" and replace them with simply "Hubble" as it is a more common short name for the telescope.
 1.14. In "Size", similar to point 1.13., remove "SST" and replace with "Spitzer".
 1.15. In "Size", merge the second and third paragraphs together, as the third paragraph is a single sentence.
 1.16. In "Size", merge the fourth and fifth paragraphs together, as after point 1.11, the fifth paragraph would also only be a single sentence.
 1.17. In "Size", change "New measurement from Herschel Space Observatory" to "Measurements from the Herschel Space Observatory in 2013" for grammatical correction and date clarification.
 1.18. In "Size", move Herschel estimates of Weywot's size to the "Characteristics" subsection of "Satellite Weywot", where it would be more appropriate.
 1.19. In "Orbit and rotation", clarify "Its orbit is nearly circular" by adding "Its eccentricity is 0.0376, meaning its orbit is nearly circular."
 1.20. In "Orbit and rotation", merge the second and third paragraphs together as they both two sentences long.
 1.20.1. Merge the paragraphs into a single block of information for the section, now that the second paragraph is only two sentences long.
 1.21. In "Physical characteristics", merge the two opening paragraphs together, as the latter is only a single sentence.
 1.22. In "Cryovolcanism", merge all of the paragraphs together to form a single tidy block of information.
 1.23. Consider moving "Cryovolcanism" to the bottom of the "Physical characteristics" section, as it illustrates a unique, specific topic, as opposed to the overviews of common topics "Size" and "Mass and density".
 1.24. Consider merging "Classification" and "Hit-and-run collision" under one "Mass and density" subsection, as the two sections share this common theme, and move it in between the opening paragraph and "Size" for alphabetical order among the common topics.
 1.25. In "Satellite Weywot", rename the section to simply "Satellite", as it better harmonises with other articles on minor planets.
 1.26. In "Satellite", replace "in IAUC 8812 on 27 February 2007" with "in an IAU Circular notice published on 27 February 2007" with a wikilink to IAU Circular. Casual readers would otherwise not know what "IAUC 8812" meant.
 1.27. In "Satellite", replace "in the Minor Planet Circular 67220" with the less technical "in a Minor Planet Circular notice", with a wikilink to Minor Planet Center#Publications.
 1.28. In "Satellite", remove the "Name" subheading and make its content part of the opening paragraph of the section, as the section as a whole is too small to justify the existence of subsection in it.
 1.29. In "Satellite", for similar reasons to point 1.28., remove the "Characteristics" subheading, merge its three small paragraphs into a single substantial paragraph, and make it the second paragraph of the section; "Satellite" should now have two distinct paragraphs.
 1.30. In "Satellite", move the passage "It was thought that Weywot may have originated from a collision with Quaoar and another large Kuiper belt object." to the end of the new first paragraph, as to not split up the passages about Weywot's discovery and naming.
 1.31. In "Satellite", correct "0.35 arcsecond" with "0.35 arcseconds".
 1.32. In "Satellite", simplify "Measurements from the Herschel Space Observatory in 2013 revised the sizes of Quaoar and Weywot. From these measurements, Weywot is given an estimated size of 81 km (50 mi)." by instead writing something along the lines of "Weywot is estimated to be 81 miles (51 kilometers) in diameter, based on observations with the Herschel Space Observatory in 2013."
 1.33. In "Exploration", merge the two short paragraphs of the section into one.
 1.34. In "Exploration", correct and clarify "In July 2016 New Horizons spacecraft took a sequence" with "In July 2016, the Long Range Reconnaissance Imager (LORRI) aboard New Horizons took a sequence", with a wikilink to Long Range Reconnaissance Imager.
 1.35. In "Discovery", make the passage about Pluto the last sentence of the section, and reword it along the liens of, "Quaoar's discovery has been cited as Brown as having contributed to the reclassification of Pluto as a dwarf planet.", with a wikilink to IAU definition of planet, in "reclassification of Pluto".
 1.36. In "Size", move the first sentence of the section to before "Measurements from the Herschel Space Observatory in 2013...", and reword the passage so that it now reads "In observations of the object's shadow as it occulted an unnamed 16th-magnitude star on 4 May 2011, Quaoar was estimated to be 1,170 km (730 mi) in diameter."
 1.37. In "Size", move the last three sentences of the section to the very start of the section, and reword the first two sentences along the lines of, "Quaoar is thought to be an oblate spheroid around 1100±5 km in diameter, being slightly flattened in shape. The estimates come from observations of Quaoar as it occulted a 15.8 magnitude star in 2013.", with a wikilink to Occultation.
 2. The article is verifiable with no original research

 2.1. In "Discovery", the passage "Quaoar was officially discovered on 6 June 2002, by astronomers Chad Trujillo and Michael Brown at the California Institute of Technology, from images acquired at the Samuel Oschin Telescope at Palomar Observatory. The actual discovery image was taken on 4 June 2002, 05:41:40 UT and analyzed on 5 June 2002, 05:48:08 UT." is slightly problematic. According to the citations given for this passage, the narrative is Quaoar was imaged on 4 June with the Oschin telescope and identified by Trujillo on 5 June, with the Minor Planet Center receiving news of the discovery on 6 June, with Brown and Trujillo officially credited for the discovery. A passage more aligned with what the citations tell us would be better. I'd suggest something along the lines of, "Quaoar was discovered by astronomer Chad Trujillo on 5 June 2002, when he identified it in images acquired by the Samuel Oschin Telescope at Palomar Observatory the night before. The discovery was submitted to the Minor Planet Center on 6 June, with Trujillo and his colleague Michael Brown credited for the discovery."
 2.2. In "Size", the claim that Quaoar was the largest object found in the Solar System since Pluto, and that it was later superseded by Eris, Haumea, and Makemake, is not sourced with an inline citation.
 2.3. In "Size", the claim that Quaoar is about as massive as Charon, 2.5 times as massive as Orcus, one twelfth the diameter of Earth, one third the diameter of the Moon, and half the size of Pluto, is not sourced with an inline citation.
 2.4. In "Size", the entire passage "Given its distance Quaoar is on the limit of the HST resolution (40 milliarcseconds) and its image is consequently "smeared" on a few adjacent pixels. By comparing carefully this image with the images of stars in the background and using a sophisticated model of HST optics (PSF), Brown and Trujillo were able to find the best-fit disk size that would give a similar blurred image. This method was recently applied by the same authors to measure the size of the dwarf planet Eris." is not sourced with an inline citation.
 2.5. In "Hit-and-run collision", the last sentence of the paragraph is not sourced with an inline citation.
 2.5.1. To clarify, this passage is "This model was made assuming Quaoar actually had a density of 4.2 g/cm3, but more recent estimates have given it a more Pluto-like density of only 2 g/cm3, with no more need for the collision theory.", and is now the last sentence of the "Mass and density" section.
 2.6. In "Orbit and rotation", the first two sentences of the section are not sourced with an inline citation.
 2.7. In "Orbit and rotation", the passage describing various KBOs on highly inclined and eccentric orbits is not sourced with an inline citation.
 2.7.1. To clarify, this passage is "Other large objects in the Kuiper belt such as Pluto, Makemake, Haumea, Orcus, Varuna, and Salacia are all on highly inclined and eccentric orbits."
 2.8. In "Orbit and rotation", the "scatnear" footnote is not sourced with an inline citation.
 2.9. In "Satellite", the passage "Its discovery by Michael E. Brown was reported in IAUC 8812 on 22 February 2007, based on imagery taken on 14 February 2006." is misleading. Both the "IAUC" and "johnston50000" sources used to cite this passage credit Michael Brown and T.A. Suer for the discovery, not just Brown, and that the Hubble Space Telescope was used. A rewrite along the lines of "Discovered by Michael Brown and T.A. Suer using images acquired by the Hubble Space Telescope on 14 February 2006, its existence was announced in IAUC 8812 on 22 February" would be needed.
 2.10. In "Satellite", the passages "From the surface of Quaoar and at a point where Weywot is at zenith it would have an angular diameter of 15.9 arcminutes at apoapsis and 21.4 arcminutes at periapsis, in comparison the Moon's size varies between 29.4 and 33.5 arcminutes. Its apparent magnitude at full phase would be about -3, comparable to Jupiter at maximum brightness." is very problematic. The "moonsize" and "moonshine" footnotes that attempt to cite these passages are explanations of how the passages were synthesised from other data. Wikipedia has a policy against original research (WP:NOR), and a verifiable source(s) to cite details of Weywot's visibility from Quaoar is needed instead.
 2.11. In "Exploration", the last sentence of the paragraph is not sourced with an inline citation.
 2.11.1. To clarify, this passage is "Quaoar is a logical flyby target for such a mission due to its close proximity to the heliospheric nose."
 2.12. In "Size", the opening passage, "Quaoar is estimated to be 1,170 km (730 mi) in diameter, and elongated in shape, according to observations of the object's shadow as it occulted an unnamed 16th-magnitude star on 4 May 2011.", has been left without an inline citation, despite having been cited in a previous version of the page when it was located towards the end of the section.
 2.13. In "Size", move the "Stern_2017" and "Williams2015" citations for the second sentence of the section, "...large and massive as (if somewhat smaller than) Pluto's moon Charon.", into the "mass" {{efn}} note itself.
 3. The article is broad in its coverage
 4. The article is neutral
 5. The article is stable
 6. The article is illustrated

 6.1. In "Size", move Quaoar hubble.jpg above the paragraph describing Hubble's observations, and remove the fixed 180px image size to allow for user preference on thumbnail width.
 6.1.1. In "Size", swap the table to the left and the image on the right, and remove the fixed image size as originally requested.
 6.2. In "Classification", remove {{TNO imagemap}}, as it does not seem to illustrate any facts or occurrences described in this section, and instead hosts a generic list of large TNOs.
 6.3. In "Orbit and rotation", consider using {{Multiple image}} to display Cubewanos.png and TheKuiperBelt Orbits Quaoar.svg more efficiently as right-aligned illustrations.
 6.4. In "Orbit and rotation", wikilink Classical Kuiper belt object for "cubewanos" in the caption for {{Multiple image}}.
 6.5. In "Physical characteristics", remove the 200px fixed image size for Quaoar-red-ssc2004-05c.jpg to allow for user preference on image thumbnail sizes.
 6.6. In "Satellite", remove Quaoar Optical.jpg from {{Infobox planet}}, as it does not illustrate Weywot in any capacity.
 6.7. In "Exploration", add "upright" to the image syntax for Quaoar animation dark crsub circle.gif. This will make the image smaller, but without sacrificing user thumbnail size preferences.
 6.8. In "Exploration", simplify the caption for Quaoar animation dark crsub circle.gif by instead stating something along the lines of "Images of Quaoar taken by LORRI at a distance of 14 AU", with a wikilink to Long Range Reconnaissance Imager.
 6.8.1. A shorter, two-line caption would help reduce the gap at the bottom of this section caused by {{Clear}} and the small amount of content in "Exploration". There does not need to be an explanation of obvious facts about the image, such as galaxies being clearly visible, and information already explained in the prose, such as LORRI being aboard New Horizons. If you insist on the spacecraft being credited instead of the camera, an alternative caption that can fit in two lines would be "Quaoar from New Horizons, viewed at a distance of 14 AU." 
I've edited the article according to your suggestions on the first two criteria. For your suggestion on Weywot, I've separated the part regarding Weywot's size otherwise there would be excessive commas. Nrco0e (talk) 20:00, 22 March 2019 (UTC)

@Nrco0e: I am content with your solution to the Weywot passage; good job so far! I've completed my review of the "Size" and "Orbit and rotation" sections of the article; my comments on those sections are listed in points 1.9 to 1.20, 2.2. to 2.8, and 6.1 to 6.3. – PhilipTerryGraham (talk · articles · reviews) 00:09, 23 March 2019 (UTC)
@Nrco0e: I have completed my review of the entire article! Feel free to give me feedback on any points that you either need clarification on or disagree with. I'll be happy to give this article the stamp of approval if a substantial amount of the suggested improvements are made. – PhilipTerryGraham (User talk:talk · articles · reviews) 05:41, 24 March 2019 (UTC)
@PhilipTerryGraham: I'd like to let you know that I'm nearly finished editing the article according to your suggestions. I'm still working on part 2 (original research); the part regarding 2.5 as massive as Orcus is removed since I didn't find it relevant to the comparison. I've made a separate reference note with a more detailed comparison of the masses of Quaoar and Charon using their measured mass values from arXiv citations. Nrco0e (talk) 00:56, 26 March 2019 (UTC)
@Nrco0e: You're doing a really good job so far! I've made some additional clarifications to some points under the second criteria to make things a little easier for you! I've also added two more post-review concerns I had about the current version of the article. For a convenient recap, all that's left are points 1.12, 2.5.1., 2.7.1, 2.8, 2.9, 2.10, 2.11.1., 2.12, and 2.13! Again, if you have any level opposition to any suggested changes, or technical problems executing some of the changes, do let me know! – PhilipTerryGraham (talk · articles · reviews) 05:00, 26 March 2019 (UTC)
@PhilipTerryGraham: Unfortunately, I cannot do much with 2.13 since putting citations in the {{efn}} note results in a cite error: Cite error: A list-defined reference named "Stern_2017" is not used in the content (see the help page). Nrco0e (talk) 03:13, 27 March 2019 (UTC)
@Nrco0e: This actually has a simple solution; move the "mass" {{Efn}} note out of {{Notelist}} and into the actual article itself, after "...(if somewhat smaller than) Pluto's moon Charon." There, you can place the citation within the note and produce no cite errors. You can also use this to solve point 2.8. as well, if this was the thing holding you back. Since you've recently added new content to the article, I've gone ahead and made some additional points. These are 1.35, 1.36, and 1.37. Please note that if you cannot find any sources to cite the passages raised in 2.7.1., 2.8, 2.9, 2.10., 2.11.1., and 2.12, you should remove those passages entirely. – PhilipTerryGraham (talk · articles · reviews) 17:52, 27 March 2019 (UTC)

I'm glad to say that I have finished editing the article for the GA review. Take your time to check if I had missed something. Nrco0e (talk) 04:18, 29 March 2019 (UTC)

@Nrco0e: One last note; you wrote over "in an IAU Circular notice published on 27 February 2007" in "Satellite" from point 1.26. when you addressed point 2.9.. I'd insist on fixing that. Other than that, I'm completely satisfied with the improvements made to the article! This article now meets the final two criteria that were left, which is that the article is well written and that it is verifiable. Once the final aforementioned fix is made, I'll go ahead and close out this review! Fantastic work, Nrco0e! – PhilipTerryGraham (talk · articles · reviews) 04:49, 29 March 2019 (UTC)

A new paper about Quaoar's second moon was published by Benjamin Proudfoot et al. on The Astrophysical Journal Letters today. With just one datapoint, they've managed to do some impressive inferences about this moon's orbital dynamics in relation to Quaoar's ring system. They also hint another two upcoming papers: one by Proudfoot et al. that will give a more accurate measurement of Quaoar's mass and Weywot's orbit, and another by Fernandez-Valenzuela et al. that will describe occultation measurements of Weywot's shape and size. Not only that, but there are several conference papers at this year's Europlanet Science Congress (EPSC) which serve as previews to even more upcoming studies on Quaoar's rings, which will eventually incorporate Quaoar's 2nd moon, as well as two Hubble proposals (17417 and 17827) focused on Weywot. This decade is surely an exciting time for Quaoar.
But first and foremost, a disclaimer on how to handle Quaoar's second moon on Wikipedia. It doesn't have an official provisional designation assigned by the IAU, so we cannot call it "S/2025 (50000) 1", even if it is technically correct. This is a similar case to many minor-planet moons like Satellite of 38628 Huya. Since these studies will inevitably bring new insights to Quaoar's second moon, at some point we'll have to make a standalone article on Quaoar's second moon. I doubt this second moon will be reobserved/confirmed/named any time soon, so deciding what to name an article for this moon will be tricky. Wikipedia:Naming conventions (astronomical objects) says that if we were to make a standalone article for an undesignated moon, we'll have to title it something like "Inner moon of Quaoar" (though that carries the problem of not making sense if a third moon of Quaoar gets discovered...). Nrco0e (talk • contribs) 04:05, 8 November 2025 (UTC)

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

Quaoar discovery animation.gif
Participate in the deletion discussion at the nomination page. —Community Tech bot (talk) 17:36, 10 November 2025 (UTC)

Another new paper by Proudfoot et al. was published on arXiv today, this time featuring a very detailed dynamical analysis of Weywot's orbit, Quaoar's shape, density, interior, and implications for ring dynamics. Lots of interesting highlights including latitudinal albedo variations on Quaoar (possibly either a bright equator from deposited ring material or dark poles from volatile transport of ethane).
This article definitely needs an update to reflect the new Quaoar studies from the past 2 years. Some things that need addressing:

Update Quaoar mass, density, and dimensions from today's new paper
Mention Quaoar may have a relatively bright equator (or dark poles)
The cryovolcanism hypothesis is outdated, if not obsolete; no ammonia hydrate was found by JWST. Reduce mention of cryovolcanism and remove from lead.
Include content from Margoti et al.'s master's thesis, cited in today's paper.
Revamp formatting and prose of the entire article (follow the Makemake article revamp)
Split off rings section into a standalone article (Rings of Quaoar)
Help is appreciated! Nrco0e (talk • contribs) 06:37, 11 November 2025 (UTC)