Talk:Orcus (dwarf planet)/GA1

GA Review

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Reviewer: Bryanrutherford0 (talk · contribs) 14:18, 20 September 2019 (UTC)[reply]

GA review (see here for what the criteria are, and here for what they are not)

It is reasonably well written.
a (prose, spelling, and grammar): b (MoS for lead, layout, word choice, fiction, and lists):
The article is written to a good prose standard and complies with the required sections of MoS, with one exception: the lead section is clear and relevant but a bit too long. MOS:LEADLENGTH indicates that the lead section of an article this size should be "one or two paragraphs." The final paragraph should be cut from the lead, since it appears to only contain information about Vanth and not Orcus; that content should be moved to the section on Vanth at the end of the body, where it will give that section a little more heft (I would put it between the two existing sentences of the final paragraph of the body).

I think the third paragraph of the lead should probably be cut as well (of course keeping all of the content in the body sections on Orcus's surface and cryovolcanism). I would probably keep the first sentence ("The surface of Orcus is...") but move it to the first paragraph after the sentence that establishes the body's diameter, which would improve the size balance between the two paragraphs. The rest of the detail here probably needs to wait for treatment in the body.

In the section "Size and magnitude", one sentence begins, "If the albedos of both bodies are the same...", but the next sentence says that a subsequent study has revealed that the albedos are not the same, requiring an upward revision of Vanth's estimated size; if that's true, then the "If they were the same..." sentence should be deleted as a distraction.

In "Spectra and surface", The first sentence of the third paragraph begins, "Orcus straddles the edge...", but to straddle something is to be on both sides of it at once. It's not yet known with certainty whether Orcus is big enough, but in reality it either is or is not, so "straddles" sends the wrong message. Maybe "Orcus sits at the threshold..."?

Regarding the use of Template:Minor planets navigator at the end: it doesn't seem like this footer navbox is really adding anything to the article without the adjacent minor planets included, but I see that we don't seem to have articles about either of them (and may never have, since neither may ever be especially notable). Probably this should be removed, unless it's serving some purpose I'm not seeing?

~~Another minor note: I would add a wikilink to psychopomp in the sentence in "Name" explaining Vanth's name, but it's not required.~~
It is factually accurate and verifiable.
a (reference section): b (citations to reliable sources): c (OR): d (copyvio and plagiarism):
The article has citations and a reference section. The online citations included support the vast majority of the article's substantive content, and I'll AGF on some of the paywalled studies for plausible physical data. Earwig's copyvio tool shows a close match between some of this article's text about the IAU's naming conventions and some other wiki/fansites, but it looks to me like that's probably because those sites ripped off this article.

Comments: I see in the infobox that we have the margins of error for all the figures in the "Physical characteristics" section, but they seem to be omitted in the "Orbital characteristics" section. Is there a reason not to include the uncertainties with those figures as well? They seem to be included on the JPL page that's cited, in the form of standard deviations (rather than a 90% confidence interval or what have you). Also, the JPL page's orbital data seem to be based on Epoch 2019 April 27.0 (as do those on the Minor Planet Center page), but the infobox claims that its orbital characteristics figures are from Epoch 4 September 2017; where did the infobox numbers come from, and should they be replaced by the figures from the JPL site?

The section "Mass and density" speculates about the division of mass between Orcus and Vanth, but the preceding section ("Size and magnitude") seems to indicate that a 2017 study nailed down Vanth's diameter to within about ±2%. Does this datum render the talk about Vanth making up between 1/33 and 1/12 of the binary system's mass outdated? If the previous section is correct, then it sounds like the relative sizes are known to much greater precision than this now.

In "Orbit and rotation", I'm uncomfortable with the phrase "Orcus is currently 48.0 AU from the Sun"; this is a sort of claim that is certain to rapidly go out of date and need continual updating. Perhaps we could cut this out and then update the remainder of the sentence to something like "Orcus has its aphelion in 2019 and will then approach the Sun until reaching perihelion in [presumably about] 2143"? That at least would keep the article up to date for the next 124 years. The second paragraph in the same section includes the claim that a rotational period of "about 10.5 hours seems to be the most likely one." Why does that figure seem the most likely, if other studies have produced other figures? Indeed, the abstract of the cited article seems to me to suggest that its authors find the possibility of Vanth's being tidally locked to be at least plausible. This claim about likelihood doesn't seem warranted by the sources I can see (but the Ortiz et al. article is paywalled, so I can't read the full text).
I've updated the orbital parameters of Orcus from the JPL Small Body Database. About the uncertainties for the orbital characteristics, the figures in the infobox are rounded and the uncertainties listed on the JPL site are very small. There is no need to include the small uncertainties if nearly all of them don't exceed 0.001. Nrco0e (talk) 01:59, 23 September 2019 (UTC)[reply]

With that aside, I have resolved the rest of your assessments. Nrco0e (talk) 02:28, 23 September 2019 (UTC)[reply]
Oh, I see, the uncertainty is beyond the precision you're reporting. Fair enough! -Bryan Rutherford (talk) 14:43, 23 September 2019 (UTC)[reply]
It is broad in its coverage.
a (major aspects): b (focused):
The article appears to cover the major aspects of the topic, including observational history, origin of name, characteristics of the body and of its orbit, and a brief summary of information about its moon. It also doesn't generally drift off topic, with a few exceptions: the chief is that it goes into too much detail about Vanth in the lead section (as discussed above). Another two come in the "Name" section, where the sentence describing the visual depiction of the deity Orcus in Etruscan tombs should be completely removed. In the same section, the discoverer's wife's given name isn't relevant and should be removed in the interest of privacy.
It follows the neutral point of view policy.
Fair representation without bias:
The article maintains an appropriately neutral tone and doesn't e.g. lionize the body's discoverers.
It is stable.
No edit wars, etc.:
It is illustrated by images and other media, where possible and appropriate.
a (images are tagged and non-free content have fair use rationales): b (appropriate use with suitable captions):
The images are relevant and appropriate, and they all have good licenses and helpful captions. It would be nice to add alt-text to all the images, but it isn't required for GA.
Overall:
Pass/Fail:
An interesting and informative article about a plutino! With a little polish, this should be able to reach the GA standard.

I have edited the article according to your recommendations. I will be waiting for your next assessments. Nrco0e (talk) 19:07, 21 September 2019 (UTC)[reply]

Wow, thank you for your quick and responsive editing! I'll look through the sources by the end of the day tomorrow and give any feedback there, but everything I've pointed out so far is now fixed. -Bryan Rutherford (talk) 20:38, 21 September 2019 (UTC)[reply]

By the way, if you haven't known already, most of the scientific papers cited in the article can be accessed from their arXiv preprints, which is linked near the end of the source citation. For your issue about the rotation period of Orcus, the full paper can be read at https://arxiv.org/abs/1010.6187. I hope this helps for your future reviews on science-related articles! Nrco0e (talk) 02:40, 23 September 2019 (UTC)[reply]

This all looks good! Thanks again for being so responsive; this article is hereby approved for GA! -Bryan Rutherford (talk) 14:43, 23 September 2019 (UTC)[reply]