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Wikipedia:Featured article candidates/Messier 87/archive1

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The following is an archived discussion of a featured article nomination. Please do not modify it. Subsequent comments should be made on the article's talk page or in Wikipedia talk:Featured article candidates. No further edits should be made to this page.

The article was promoted by Ian Rose via FACBot (talk) 16:40, 12 May 2018 [1].

Messier 87

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Nominator(s): AhmadLX (talk•cont) 03:22, 20 March 2018 (UTC)[reply]

This article is about an elliptical galaxy in Virgo cluster, some 50 million light years from Earth. It is famous for its enormous supermassive black hole which weighs about 6 billion solar masses and a relativistic jet emanating from the core, that extends up to some 4500 light years. This article was listed as GA in 2010, has been improved over this period of time, has been reviewed recently and I have also made some improvements. So article is broad in coverage, neutral, stable, well referenced and thorough. And so, I believe it meets FA criteria. AhmadLX (talk•cont) 03:22, 20 March 2018 (UTC)[reply]

Comments by Lingzhi

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Did more than one person add the references? They seem to be in at least two different styles, perhaps more. Lingzhi ♦ (talk) 09:55, 20 March 2018 (UTC)[reply]

Yes, article has been on Wikipedia for 15 years and many people have added references. But all citations are in <ref>author, year, publication name, publisher, volume/issue/edition, page, bibcode/isbn</ref> style and none in Harvard (author,year,page) style. So they seem to be consistent. Could you please provide a specific example? Thanks --UbedJunejo (talk•cont) 16:14, 20 March 2018 (UTC)[reply]
Sure. Compare the formatting of the page numbers of the book sources in fn 2, 6 and 14 - all different Hawkeye7 (discuss) 22:17, 20 March 2018 (UTC)[reply]
Fixed it--UbedJunejo (talk•cont) 03:42, 22 March 2018 (UTC)[reply]

Comments by Hawkeye7

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Image review
  • All images have appropriate licences, at but one being from NASA, ESA or ESO. I updated one licence on Commons.
  • The exception is File:Virgo constellation map.svg. Seems to be okay. The copyright holder asserts (on his talk page) that the legal status of all my star maps is the GFDL

Therefore, all images have appropriate licences. Hawkeye7 (discuss) 22:17, 20 March 2018 (UTC)[reply]

  • Suggest moving fn 25 into the Notes section
Done.
  • Template:Cite journal is called with more than one value for the "display-authors" parameter.
Done.
  • Weirdness: The DOI system says that the DOI for fn 74 is wrong. I checked it against the journal page [2], and it is indeed what it says.
Hawkeye7 (discuss) 22:17, 20 March 2018 (UTC)[reply]
Now it is number 73. DOI is as given in the article pdf. May be, as the doi.org says, The DOI has not been activated yet. :-/ --UbedJunejo (talk•cont) 02:28, 21 March 2018 (UTC)[reply]
I considered that, but the article was published in 2014. Hawkeye7 (discuss) 04:49, 21 March 2018 (UTC)[reply]

Support Hawkeye7 (discuss) 04:49, 21 March 2018 (UTC)[reply]

Comments by Praemonitus

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Support – I gave it a read through and it mostly seems reasonable from an accuracy perspective. However, there are a few items that may need to be addressed:

  • There is no mention of it being a LINER-type active galaxy. A discussion of what this means for M87 would seem appropriate.
Done (in section properties).--UbedJunejo (talk•cont) 17:50, 25 March 2018 (UTC)[reply]
  • There is no discussion (I could find) of its enormous radio lobes,[3] or the implications thereof.
Done (in jet section). Unfortunately, I couldn't find a free image.--UbedJunejo (talk•cont) 01:43, 23 March 2018 (UTC)[reply]
  • Regarding the statement: "At the time it was the only known example of an elliptical nebula for which individual stars could be resolved": the reference for this sentence says on page 51 that this claim has been criticized because, at that distance, clusters and groups would be indistinguishable from individual stars. I have to suspect that what was being detected were members of the globular cluster population rather than individual stars, but I'm not sure how that could be referenced.
I think I have fixed it in a reasonable way. You may have a look.--UbedJunejo (talk•cont) 12:20, 22 March 2018 (UTC)[reply]

Thank you. Praemonitus (talk) 19:53, 21 March 2018 (UTC)[reply]

Comments by Graeme Bartlett

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Done
"refer to caption" is not up to the standard required. The idea is to say what the picture looks like for those that cannot see the image. It is not to replace the caption. Graeme Bartlett (talk) 21:36, 22 March 2018 (UTC)[reply]
It is not possible to describe many images of the article without introducing redundancy. One can not explain how X-ray emission looks like to somebody who can not see it. Nevertheless, I have tried to fix most of them.--UbedJunejo (talk•cont) 01:47, 23 March 2018 (UTC)[reply]
The idea is just to say what we see. We don't see X-rays, but you can say what we see in the pic, a yellow circle with red bubbles coming out the top and bottom, upper right, and lower left, A blue beam shoots to the top and another to the lower left. Graeme Bartlett (talk) 05:13, 23 March 2018 (UTC)[reply]
I have seen the pic before, but still, while reading this description, I couldn't generate any visual in my mind that matches with actual image. Maybe you should add "deformed rectangular region, with red shades, surrounded by blue background, with many stars .......". But as policy page says "alt text needs to be short and to the point, detailed explanation should be left to body". On the other hand, caption is descriptive and to the point.UbedJunejo (talk•cont) 12:37, 23 March 2018 (UTC)[reply]
Done. Previous caption was inaccurate. Fixed that + equivalent description in alt. You may have a look.--UbedJunejo (talk•cont) 17:52, 25 March 2018 (UTC)[reply]
  • ö B¨ohringer should be Böhringer
Done
  • extragalactic or extra-galactic
Titles of publications are not altered, other instances fixed.
  • Gebhardt or Gehbardt (initial K - probably the same person)
Done
  • intracluster or intra-cluster
Same as number 3
  • Inconsistent apostrophe: M87’s or M87's
Fixed
  • 'p' - should this be in double quotes "p"?
Done
  • In the Jet section there is a phrase "and vice versa" but it is not clear, do you mean the reverse faster→smaller or opposite bigger→slower.
"vice versa" is not commutative, I think ;) So, "small diameter=fast variation", --vice versa--> "large diameter=slow variation", i.e it will take first argument first and reverse :D
  • At one point Virgo-A makes a mention, but later it is always "Virgo A".
Fixed
  • Should VIRGO CLUSTER in reference 91 be all caps?
Fixed
  • Slight inconsistency with X-Ray (in external link) or X-ray in text
Fixed (as X-ray), although it was in publication title, but since title was all caps, so justified I guess
Done (wherever wiki article exists)--UbedJunejo (talk•cont) 13:59, 22 March 2018 (UTC)[reply]
  • Also where authors have articles use authorlink. (The first I checked Christian Luginbuhl, has no article, but does have an asteroid named after him!) but Brian A. Skiff exists

(I will check references and also do a spelling and symbol check) Graeme Bartlett (talk) 11:42, 22 March 2018 (UTC)[reply]

Support from Comments from Jim

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Looks pretty comprehensive, just a couple of nit-picks

  • it lacked any spiral structure, but appeared to belong to the same family of non-galactic nebulae as spiral nebulae—a few words explaining why it's classed with spirals despite not being one might be helpful
It actually means that it was identified as non-galactic nebula (like spirals, which were also identified as being far from the Milky Way), as opposed to galactic nebula (like planetary nebulae, which are within the Milky Way). I have clarified it a bit in the article.
  • with former being independent star systems—"the former"?
Done.--UbedJunejo (talk•cont) 21:50, 4 April 2018 (UTC)[reply]

Jimfbleak - talk to me? 13:23, 3 April 2018 (UTC)[reply]

Forgot to watchlist, happy with changes, supported above Jimfbleak - talk to me? 15:33, 15 April 2018 (UTC)[reply]

Comments Support from Cas Liber

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Looking pretty good overall...notes below:

  • ...it has been shown that M87 has absorbed a medium-sized star-forming spiral galaxy over the period of last billion years. "the" last billion years? or even better "sometime within the last billion years"?
Done
  • I'd link chevron, and corona
I am not sure on this one, if it would be appropriate.
Agree/point taken. Ok not a dealbreaker Cas Liber (talk · contribs) 02:45, 11 April 2018 (UTC)[reply]
  • Gamma rays coming from M87 have been observed since the late 1990s, but in 2006, using the High Energy Stereoscopic System Cherenkov telescopes, scientists have measured the variations of the gamma ray flux coming from M87, and found that the flux changes over a matter of days. - I'd split this long sentence
Done
  • Interaction of relativistic jets of plasma emanating from the core with surrounding medium gives rise to radio lobes in active galaxies. - should there be a "the" before "surrounding"?
Done.UbedJunejo (talk•cont) 14:09, 10 April 2018 (UTC)[reply]

Ok - all looks good prose and comprehensivenesswise Cas Liber (talk · contribs) 02:45, 11 April 2018 (UTC)[reply]

Coord notes

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  • I can see that sources were checked for formatting but not sure if anyone's signed off on reliability.
  • Also since I believe this would be the nominator's first FA if successful I'd like to see a spotcheck of sources for accurate use and avoidance of close paraphrasing.

Cas, given your experience with such articles I thought this might be a mission for you, should you choose to accept it... ;-) Cheers, Ian Rose (talk) 07:13, 28 April 2018 (UTC)[reply]

Earwig's looks ok. Will spot check a bit later. Cas Liber (talk · contribs) 07:23, 28 April 2018 (UTC)[reply]
  • FN 27 - used once, material cited and faithful to source.
  • FN 37 - used twice, material cited and faithful to source.
  • FN 78 - used once, material cited and faithful to source.

Spot checks ok. Cas Liber (talk · contribs) 12:21, 28 April 2018 (UTC)[reply]

Many thanks for quick response, Cas -- are you satisfied with the reliability of the sources used? Cheers, Ian Rose (talk) 12:53, 28 April 2018 (UTC)[reply]
Yes. Some web pages of astronomers have layout issues but the content is good. Cas Liber (talk · contribs) 01:03, 29 April 2018 (UTC)[reply]

Comments Support by Ceoil

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Apologies, non expert here, so checking for accessibility. Note I expect to support

  • The term 'encountered' is used 6 times but was not linked - is this collision?
You've already linked that.
I was wondering if I was correct - linked local group in the same edit, which was reverted since Ceoil (talk) 02:56, 29 April 2018 (UTC)[reply]
  • Wording: "both amateur astronomy observations and professional astronomy study. French astronomer Charles Messier discovered M87" - astronomy, astronomy, astronomer.
Astronomy related article is gonna have that word anyway ;)
I am dissapointed in your reply, we have FAC criteria 1.a for a reason, and its easier to do better. "To both amateur and professional astronomers". Ceoil (talk) 02:56, 29 April 2018 (UTC)[reply]
Agreed on that change.UbedJunejo (talk•cont) 17:53, 29 April 2018 (UTC)[reply]
  • "cataloguing it as a nebulous feature while searching for objects that would confuse comet hunters". I understand the point from later in the article, but here "that would confuse comet hunters" is confusing (ironically)- was he was out to confuse comet hunters?
He wanted to sort out things that would confuse comet hunters, so off course he was helping them
of course, but you are missing the point. Can you be more clear wrt intent. Ceoil (talk) 03:08, 29 April 2018 (UTC)it[reply]
No, it conveys the meaning properly. I undid your changes on this as your edit "..while mapping objects that could be distinguished from comets" sounds like his aim was separate comet-non-comet things. His aim was to only identify the objects that could potentially, and incorrectly, be identified as comets.UbedJunejo (talk•cont) 17:53, 29 April 2018 (UTC)[reply]
  • Similarly - "as part of a list intended to identify objects that might be confused with comets" - to separate or distinguished...objects...that might otherwise be identified as?
Done.
  • there was no spiral structure in M87 - M87 did not have a spiral structure? I dont get "in".
In my view, both seem okay. You can change if you prefer the second one.
I do. Ceoil (talk) 22:25, 29 April 2018 (UTC)[reply]
  • What is an "inner end"
"inner end" means core region, where the jet originates. Seems obvious to me.
Bully for you, but I'm reviewing as a non expert for accessibility. "Seems obvious to me" doesnt cut it. Have edited this in now anyhow. Ceoil (talk) 03:00, 29 April 2018 (UTC)[reply]
Sorry, I was just making my point, not bullying. thank you :) --UbedJunejo (talk•cont) 03:18, 29 April 2018 (UTC)[reply]
  • oops, its an Irish colloguial term, it means "good for you", not anything else!!! I appreciate all this is second nature to you, but the rest of us need very tight descriptive language and blue links to navigate. Ceoil (talk) 03:28, 29 April 2018 (UTC)[reply]
"Seems obvious" not because of technicality but because of the language. "Inner end" here means what it may mean in any other context: part near the origin, on the inner side.UbedJunejo (talk•cont) 17:53, 29 April 2018 (UTC)[reply]
Junejo, this seems to get to the core (if you'll forgive the pun) of our disagreement. You think the page is already a sea of blue links, for an uninciated novice like me, the links are vital grounding. I'd put "Inner end" and "Local Universe" as at the core of why I had found the page unsatisfactory. Ceoil (talk) 22:09, 29 April 2018 (UTC)[reply]
Ok, so what do you suggest for linking "Local Universe" to? It can not be local group. I am not even sure if linking to "virgo supercluster" is okay, but it is already linked later in the article. Secondly, I am also novice in the field.--UbedJunejo (talk•cont) 23:17, 29 April 2018 (UTC)[reply]
Suggest that it is described as regions within a billion light years; per the sources you provided below. Ceoil (talk) 23:37, 29 April 2018 (UTC)[reply]
  • By 1931, Hubble had identified M87 - Why "by 1931", did he not publish his finding
Fixed. UbedJunejo (talk•cont) 17:53, 29 April 2018 (UTC)[reply]
  • All estimates are provisional. First estimated?
Could you please clarify this? thanks in advance
This is just a matter of basic clarity and tense. When, what sequence of discovery. One of the two words is redundant. Ceoil (talk) 03:14, 29 April 2018 (UTC)[reply]
Please provide the sentence where you think clarification is needed.UbedJunejo (talk•cont) 17:53, 29 April 2018 (UTC)[reply]
  • Had two windows open - rephrasing as I was compiling here. Ceoil (talk) 23:10, 7 May 2018 (UTC)[reply]
  • It was then the only known elliptical nebula for which individual stars could be resolved - can we link "resolved"
Article is already quite blue with links. Doesn't seem necessary to me. Maybe somebody else will agree :-/
Resolution is a common term; context is evident that resolution here means that "objects could be identified separately" and not, for example, "dispute resolution".UbedJunejo (talk•cont) 17:53, 29 April 2018 (UTC)[reply]
  • Again: "This source was confirmed to be M87 by 1953" - can we be more precise than "by" 1953
Old literature :-/ Difficult to be precise. Finding all publications on the topic from that period is difficult.
This raises issues of comprehensive research. Ceoil (talk) 04:47, 29 April 2018 (UTC)[reply]
It took me a month to figure out exactly why and when was M87 called galaxy. We didn't have arxive, bibcode back then.UbedJunejo (talk•cont) 17:53, 29 April 2018 (UTC)[reply]
  • That is, about one part in six of the galaxy's mass is in the form of stars that are radiating energy. The total mass of M87 may be 200 times that of the Milky Way. - Given "That is", should this read "stars that are radiating energy, and the total mass of M87..." ie both claims arise from the same findings.
The 200 times thing doesn't directly come from mass-luminosity ratio.
  • There are tense issues throughout, eg "was being generated" (is generated unless we are assuming the galaxy has died since the light reached us), or The total energy output of these electrons was estimated as, then "the entire Milky Way galaxy output is estimated" etc
Use of "suggested" requires "was". Also "was estimated" when we are referring to the measurement in distant past. You won't say "Hubble has identified M87 as external galaxy".UbedJunejo (talk•cont) 17:53, 29 April 2018 (UTC)[reply]
  • Lobes of matter from the jet extend out to a distance of 77 kiloparsecs (250 thousand light-years).[84] - Is "lobes" the right word here? Lobes usually form a pair.
There is actually a pair of lobes, visible in radio. Also, jet is bipolar, as discussed in the article.
then say so - surely so we can link lobes so it doesnt sound careless. Remember the audience. Blue links (like seem clutter to you, but are lifelines to the rest of us. Ceoil (talk) 03:14, 29 April 2018 (UTC)[reply]
What would be destination link in your view? I have linked "radio lobes" to "radio galaxy" which occurs later in jet section. UbedJunejo (talk•cont) 17:53, 29 April 2018 (UTC)[reply]
  • Linking: please clarify what local universe means. Had thought local group, is it Virgo Supercluster?
These sources define local universe something from 50 million to a billion light years. It is certainly larger than Local Group.
So...the Virgo Supercluster, or? You havnt rearlly answered my question. Ceoil (talk) 03:00, 29 April 2018 (UTC)[reply]
Links that I have given address the issue: it is not clearly defined. Local universe means different to different people. But it is not akin to local group.UbedJunejo (talk•cont) 17:53, 29 April 2018 (UTC)[reply]
Added note, as you've suggested above.UbedJunejo (talk•cont) 17:11, 1 May 2018 (UTC)[reply]
Thanks. Ceoil (talk) 23:08, 7 May 2018 (UTC)[reply]
Thank you ;) --UbedJunejo (talk•cont) 02:49, 29 April 2018 (UTC)[reply]
  • the seeming position of the galaxy center with respect to the black hole - should "with respect to" be "in relation to".
What is the difference to be honest?UbedJunejo (talk•cont) 17:53, 29 April 2018 (UTC)[reply]
Gaa, ok, but I'll just fix it. Ceoil (talk) 22:32, 29 April 2018 (UTC)[reply]
Unlinked. Link to HVGC1 is given.UbedJunejo (talk•cont) 17:53, 29 April 2018 (UTC)[reply]
  • The contribution from these sources was much lower in abundance than in the Milky Way - "abundance" - volume, density, frequency or?
Fixed. I really appreciate this objection, solid and objective ;)--UbedJunejo (talk•cont) 01:20, 1 May 2018 (UTC)[reply]
  • the emission appears to be fully explained by synchrotron radiation from the jet - We follow "appear to be" with "fully explained"?
Done--UbedJunejo (talk•cont) 21:55, 30 April 2018 (UTC)[reply]
  • optical filaments have been observed in M87 - drop "in M87", its clear in which galaxy
Done--UbedJunejo (talk•cont) 22:31, 29 April 2018 (UTC)[reply]
  • 'A 2006 survey out to an angular distance of 25′ from its core estimates that there are 12,000 ± 800 globular clusters in orbit around M87. Add the word "found".
It is an estimate, 12,000 ± 800. "Found" would require some more precise number.--UbedJunejo (talk•cont) 22:31, 29 April 2018 (UTC)[reply]
  • The size of the M87 clusters shows - plural: 'cluster shows'
There are thousands of globular clusters in M87, so "clusters" seems okay--UbedJunejo (talk•cont) 22:31, 29 April 2018 (UTC)[reply]
  • Several possibilities have been suggested - better "may explain" - makes it more about fact than personalities
It is not a fact. One paper has explored the possibilities. It is to be presented as it is. "May explain" would require more publications on the topic.--UbedJunejo (talk•cont) 22:31, 29 April 2018 (UTC)[reply]
Ok. Can you express this on the article body. Ceoil (talk) 22:38, 29 April 2018 (UTC)[reply]
You mean adding that "one research group has suggested....", or?--UbedJunejo (talk•cont) 23:09, 29 April 2018 (UTC)[reply]
yes, "one study"; vs "Several possibilities" Ceoil (talk) 00:02, 30 April 2018 (UTC)[reply]
Fixed.UbedJunejo (talk•cont) 17:11, 1 May 2018 (UTC)[reply]
  • decreasing with increasing - can you rephrase
I couldn't find it. Can you give the whole sentence?--UbedJunejo (talk•cont) 21:43, 29 April 2018 (UTC)[reply]
  • In subsequent use -don't like this, even "later" would be better. "each item" - object?
Replaced "item" with "entry", as it sounds even better.--UbedJunejo (talk•cont) 21:43, 29 April 2018 (UTC)[reply]
I'd still prefer "object" here. Ceoil (talk) 22:25, 29 April 2018 (UTC)[reply]
  • 1 (a) - consecutive sentences opening with the same words - "The term nebula persisted for some time thereafter and M87 continued to be called an extragalactic nebula at least until 1954.[15] The term was replaced by..".
Fixed.--UbedJunejo (talk•cont) 21:43, 29 April 2018 (UTC)[reply]
  • Their nature is unclear as to whether they are dwarf galaxies captured by M87 - "Their nature" is vague; don't like "as to whether" either.
Fixed.--UbedJunejo (talk•cont) 21:43, 29 April 2018 (UTC)[reply]
  • active elliptical galaxies of a form similar to M87 - instead of "of a form similar"; "such as"
Done.--UbedJunejo (talk•cont) 21:43, 29 April 2018 (UTC)[reply]
  • There is now little dust - I'd be careful of terms such as "now", given it's 53.5 million light-years from Earth.
That is same with all astronomical objects. So now is better than having "there was litle dust 53 my ago"--UbedJunejo (talk•cont) 14:56, 29 April 2018 (UTC)[reply]
I very much doubt that astronomers use terms such as "now" so flippantly without any context of scale - again no links on units to guide the reader. "There was a litle dust" - please, if your going to descent to farce we are done here. Ceoil (talk) 15:15, 29 April 2018 (UTC)[reply]
The para ending In general, the smaller the diameter of the emission source, the faster the variation in flux, and vice versa. is uncited.
It would be nice if an expert had a look over before it was considered for promotion. I think we have a very, very bright and knowledgeable editor who could do with help in polish and exactitude before it is taken over the line. My gut feeling is that this nom will need a second go. Ceoil (talk) 09:35, 29 April 2018 (UTC)[reply]
First of all, I was not around for a few hours as I was sleeping and you took it personal that I am not responding. Nominator is not supposed to notify reviewers about that, I guess. Nominators are supposed to address objections raised in a couple days. I discussed a few of them at night and thought to do the rest latter in the day. Secondly, many of your objections were subjective and so I honestly gave my opinions on them. You seem to have taken that quite personal as evidenced by your message on my talk. As a nominator, I do not think I am supposed to accept all opinions just to garner support. I will accept and work on objections that are objective and reasonable. If you see comments by other people above, I have not agreed to all comments/suggestions. But other people did not take that as being kind of insulting or rude behavior. I still have to go through your recent suggestions/objections and again I will implement those which seem reasonable to me. Others, if you find necessary, you can do yourself. The article is not mine. I am here to help and contribute and so is everybody else. I will not implement any suggestion that, to my mind, doesn't add much to the article. If it means facing opposition, so be it. Thank you for your understanding. UbedJunejo (talk•cont) 14:24, 29 April 2018 (UTC)[reply]
Ok, yes you have a point. But Jesus Christ, all this is irrelevant and I was rather hoping you would address on substance. I took nothing personal, was simply unimpressed with your curt and dismissive unsigned replies, and senced a tooth and nail non-meeting of minds. But again, pff. So, wot do? Address points or blow smoke? I took a lotm of time to review the page, as I was excited and engaged by it, but if you only want to blow smoke; I think your article falls below standard and you should withdraw and rethink, if you are serious about this, is my advice to you. Ceoil (talk) 14:33, 29 April 2018 (UTC)[reply]
I appreciate the time and effort that you have put in reading and suggestions. I have addressed almost half of the points and will do the rest today and tomorrow. I think the article is up to the mark, so I will not withdraw the nomination. Thanks. UbedJunejo (talk•cont) 20:38, 29 April 2018 (UTC)[reply]
Indeed you have. Ceoil (talk) 21:09, 29 April 2018 (UTC)[reply]

Am very encouraged by both Outriggr's detailed review below, and AhmadLX's (formerly UbedJunejo) keen and informed responses. Note however AhmadLX is not the primary editor and has 892 edits total to wikipedia over a three year career. I would be assured by a more detailed source review, quality is one thing, claims another, my fear here is incremental tacked-on edits that might have slipped through. Ceoil (talk) 17:35, 7 May 2018 (UTC)[reply]

As far as I know, having certain number of edits on Wikipedia or being primary editor of the article is not a requirement for FA nomination: only familiarity with the subject is required. Source formatting was done (as per suggestions above), and source review was also done by another editor. Regards. UbedJunejo (talk•cont) 18:20, 7 May 2018 (UTC)[reply]
Yes, ideally, but there is the matter of diligence. You provided 10.5% of the content. Cas performed 3 random spot-checks. I would like to hear that you performed a more extensive audit before the nom. Ceoil (talk) 18:47, 7 May 2018 (UTC)[reply]
I did many things before nom, including source checks, copyright checks and other stuff. But I didn't brag ;) UbedJunejo (talk•cont) 18:53, 7 May 2018 (UTC)[reply]

I notice RJHall contributed much of the content; he is an editor I am inclined to trust, and you also seem impressive; but it pays to be sure with first noms. Re sources

  • Ref 22: ok
  • Ref 49: Claim "The extended stellar envelope of this galaxy reaches a radius of about 150 kiloparsecs (490 thousand light-years)" - Source: "M87's gravitational reach extended about one-third as far as predicted" - I'm not seeing further back up here
This has been fixed.UbedJunejo (talk•cont) 20:19, 8 May 2018 (UTC)[reply]
  • Ref 93: ok
  • Ref 97: ok
Ceoil (talk) 20:08, 7 May 2018 (UTC)[reply]
I am doing detailed source review again: will update here.UbedJunejo (talk•cont) 14:47, 8 May 2018 (UTC)[reply]
  • Sources 1-27, covering infobox, lead, Observation history: all okay, except number [2] and [23], which are from books that I don't have access to.
  • Sources 28-60, covering Visibility and Properties (+recurrence of previous ones in these sections): all okay, except: [29], [32], [44] and [59], which are books that I don't have access to.
  • Sources 61-102, covering Components, Jet, and Environment (+recurrence of previous ones in these sections): all okay.(A couple issues found and fixed). UbedJunejo (talk•cont) 01:01, 9 May 2018 (UTC)[reply]

Support - I wont be editing during the next week and don't want to leaving this hanging, so will assume that the final points will be cleared up by UbedJunejo, who has been very responsive and engaging so far. The nominator has a low edit wiki account, but after a reasonably in dept trawl thorough the article, I'm not seeing any red flags, assured by RJHall's authorship and the current stewardship, and the rather very well informed and helpful responses during this review. I'm still not happy with the phrasing re "that would confuse comet hunters", but whatever. These astronomy articles are a considerable cap in our bow, endlessly fascinating, and post the review 2nd after this one (note that 213.205.251.29 is not me, I dont have to log out to speak my mind) am happy that the page is accessible and clear and am pleased to support. Ceoil (talk) 22:00, 7 May 2018 (UTC)[reply]

Encouraging comment by 213.205.251.29

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  • Encouraging comment from a passing anonymous editor. This is a very nice article - no doubt due to the helpful feedback that has already been supplied. It definitely needs further thorough review by someone who is not a subject matter expert to make sure it makes sense to the non-expert reader, and by someone detached from the subject who can smooth out any remaining bumps and wrinkles in the prose. Inevitably there will be quite a few blue links in this sort of technical article, so the putative high school student we might be aiming at will be able to make head or tail of it. 213.205.251.29 (talk) 00:41, 30 April 2018 (UTC)[reply]

comments by Outriggr

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Hi; I noticed the above and took a look at the article. There are lots of areas for improvement despite the support votes:

  • In the Yerkes (Morgan) scheme, M87 is classified as a type-cD galaxy; a supergiant D class galaxy. Why not explain what both the "c" and the "D" mean, per the linked article? This is half redundant as it stands. I believe the next sentence may explain it, in which case the part after the semi-colon would be better removed and integrated into the next sentence.
Done.--UbedJunejo (talk•cont) 23:26, 2 May 2018 (UTC)[reply]
  • Sometimes "galactic" is the adjective, but I have noted "galaxy" used as an adjective as well. There are times where this may be unavoidable because of terminology, but surely "galaxy center" for example would be better as "galactic center"? Please check them all.
Fixed. Only one such instance in the article..--UbedJunejo (talk•cont) 23:26, 2 May 2018 (UTC)[reply]
  • Twice in the article the abbreviation "kpc" is used when the article goes out of its way not to abbreviate (kilo)parsecs the rest of the time.
Fixed two instances as kiloparsecs. Other two instances in caption and table kept as kpc.UbedJunejo (talk•cont) 17:48, 1 May 2018 (UTC)[reply]
  • Is there any reason that The mass of M87 within a radius of 9–40 kiloparsecs (29–130 thousand light-years) from the core steadily increases roughly in proportion to r^1.7, where r is the radius from the core can't be rewritten as The mass of M87 within a radius (r) of 9–40 kiloparsecs (29–130 thousand light-years) from the core steadily increases roughly in proportion to r^1.7?
Done.UbedJunejo (talk•cont) 23:26, 2 May 2018 (UTC)[reply]
  • "Center" and "centre".
Fixed as "center".UbedJunejo (talk•cont) 17:48, 1 May 2018 (UTC)[reply]
  • This is not a sentence, but maybe the result of a recent editing mix-up: Forming around one sixth of M87's mass, its stars have a nearly spherically symmetric distribution, their population density decreases with increasing distance from the core.
Fixed, I guess ;) UbedJunejo (talk•cont) 17:58, 4 May 2018 (UTC)[reply]
Fixed.UbedJunejo (talk•cont) 17:48, 1 May 2018 (UTC)[reply]
  • In April 1965, the United States Naval Research Laboratory group --there are already five adjectives or nouns in a row here, is the sixth, "group", needed? Also, this sentence begins the paragraph, but is insufficient as a topic sentence. Can we say why they launched the rocket? I know it's implied from further reading, but clearer writing is the only chance a lay reader has. The second sentence here, This flight discovered seven candidate X-ray sources, including the first extragalactic X-ray source; Virgo X-1 was designated as the first X-ray source detected in Virgo, is poor.
What about replacing both of these sentences with "In 1966, Virgo X-1, the first X-ray source in Virgo, was identified by Aerobee 150 rocket"?UbedJunejo (talk•cont) 00:35, 3 May 2018 (UTC)[reply]
Done, as you have suggested below. UbedJunejo (talk•cont) 17:58, 4 May 2018 (UTC)[reply]
  • M87 has been an important testing ground...--I don't think "testing ground" works idiomatically for an astronomy topic, but that's just my opinion, I suppose. Update: consider stricken, it will do. Outriggr (talk) 01:02, 4 May 2018 (UTC)[reply]
  • as an "early release observation" designed to test the scientific performance of the post-repair Hubble instruments--the part in quotes is confusing, and then I wondered, is this context necessary to the article?
"Early release" thing refers back to the "testing ground" thing, that you have agreed on keeping ;) UbedJunejo (talk•cont) 17:58, 4 May 2018 (UTC)[reply]
  • There is some evidence of linear streams of stars to the northwest of the galaxy, which may have been created by tidal stripping of orbiting galaxies, or by small satellite galaxies falling in toward M87,[48] as well as...--this sentence is too long, and it becomes unclear what "as well as" refers back to, if anything.
Split into two sentences. UbedJunejo (talk•cont) 00:23, 4 May 2018 (UTC)[reply]
  • The mechanism and ionizing source for such behavior of LINERs and M87 is under debate. Please clarify; "such behavior of LINERs and M87" is awkward, as is the passive and vague "have been claimed as the causes" in the next sentence.
Fixed. UbedJunejo (talk•cont) 17:58, 4 May 2018 (UTC)[reply]
  • their stellar content is primarily an old population--"is primarily a population of old stars"? * * with little or no ongoing star formation at the present epoch--are "ongoing" and "at the present epoch" redundant?
Fixed.UbedJunejo (talk•cont) 17:48, 1 May 2018 (UTC)[reply]
  • This has resulted in addition of some younger, bluer stars to M87.--is this just the result of a missing "the"?
Fixed. UbedJunejo (talk•cont) 17:58, 4 May 2018 (UTC)[reply]

I have the last three sections left to read again. Regards, Outriggr (talk) 03:45, 1 May 2018 (UTC)[reply]

To continue: Outriggr (talk) 01:59, 2 May 2018 (UTC)[reply]

  • The sentence Analysis of M87 in 2011 did not find any statistically significant displacement ends a paragraph in which the opposite is stated (as I understand it). In that case, some kind of acknowledgement of the contrary finding is needed, possibly as simple as the insertion of "however".
Done. UbedJunejo (talk•cont) 01:10, 3 May 2018 (UTC)[reply]
  • I would suggest that this sentence, which ends a paragraph, is the topic sentence and should introduce the paragraph (with additional clarifications): Almost a hundred have been identified from the thousands of globular clusters in M87. The paragraph reads as hypothetical right now, making no mention that it is discussing uncertain objects in M87 until the end of the paragraph.
Done. UbedJunejo (talk•cont) 01:10, 3 May 2018 (UTC)[reply]
  • 1.5 kiloparsecs (5 thousand light-years)--this should be "5,000" to be consistent with the rest of the article. Not sure how to do that in the convert template.
I think, 5 thousand is okay because other values, when larger then thousand, are written just like that (e.g. 53.5 million light-years). In parsecs we have "kilo" thing, but it is not used with light-year. When value is less than thousand light-years (kilo in pc) numerals are given (e.g. 82 light years). I have changed the other instance, where it was given as 490,000 light years, accordingly (to 490 thousand light years). Except first 4,900 value, as 4.9 thousand looks ugly. UbedJunejo (talk•cont) 01:14, 3 May 2018 (UTC)[reply]
  • The total energy output of these electrons is estimated at 5.1 × 1056 ergs (5.1 × 1049 joules or 3.2 × 1068 eV). By comparison, the entire output of the Milky Way is estimated at 5 × 1036 joules per second (watts). I don't understand how this is a comparison when the measurement used for the Milky Way is a different unit from any of three mentioned in the preceding sentence.
Yes it is kind of weird comparison as M87 values are energy values and Milky Way values are power values. But energy value for M87 jet electrons can not be converted to power, unless power output is measured. The comparison actually means that energy of electrons (not their energy output) in M87 jet is say 10^13 times the energy MW generates in one second. It is certainly not obvious. I will either add note here, or will rephrase the sentence.UbedJunejo (talk•cont) 17:38, 3 May 2018 (UTC)[reply]
Rephrased and clarified: "The total energy of these electrons is estimated at 5.1 × 10^56 ergs[83] (5.1 × 10^49 joules or 3.2 × 10^68 eV). This is roughly 10^13 times the energy produced by the Milky Way in one second, which is estimated at 5 × 10^36 watts (joules per second)". UbedJunejo (talk•cont) 19:10, 3 May 2018 (UTC)[reply]
  • It is proposed that M87 could be a BL Lacertae object (with a low-luminosity nucleus compared with the brightness of its host galaxy) seen from an unfavorable angle to appreciate the properties of that kind of galaxy. I don't understand "to appreciate the properties of that kind of galaxy". Later: oh, I get it now, but it could be phrased better: e.g. "seen from an unfavorable angle that makes observation difficult" or whatever.
Modified. UbedJunejo (talk•cont) 20:34, 3 May 2018 (UTC)[reply]

I have performed quite a lot of copyediting of the article in conjunction with this feedback. [4] (Plus what others have done before me!) It should be reviewed for unintended changes in meaning. The goal was to simplify sentences, reduce redundancy ("a distance of"), remove phrases like "This is because" (which are always a sign that more fluid phrasing can be made), etc. Outriggr (talk) 01:59, 2 May 2018 (UTC)[reply]

I have reversed two changes you made: 1) Inserted back "Selected" in "Elemental abundances...." since otherwise it means only these elements are there in the core, which is not true. Table lists those for which abundances have been reported. 2) "..contains various ions' emission lines.." to "..shows emission lines of various ions.." as ions' is rarely used in literature and contains is inappropriate in this context.UbedJunejo (talk•cont) 17:58, 4 May 2018 (UTC)[reply]

OK. I will gather a few responses here rather than thread them above.

  • You now have Even though, flux variations, characteristic of the BL Lacertae objects, have been observed in M87, which is a sentence fragment. Also, this supports the previous sentence's proposal doesn't it?--so I don't understand "even though". Can it just be "Flux variations, ... in M87."?
I added "even though" to emphasize on its BL Lac nature: "despite being viewed from a large angle, it shows BL Lac characteristics". Also, "Flux variations, ... in M87." seemed dry to me. But if its not okay, it can be removed. UbedJunejo (talk•cont) 01:31, 4 May 2018 (UTC)[reply]
It is good now. "Even though" doesn't emphasize, it contrasts or suggests an alternative circumstance. So what you have now makes more sense--the sentences support each other: It is proposed that M87 could be a BL Lacertae object (with a low-luminosity nucleus compared with the brightness of its host galaxy) seen from a relatively large angle. Flux variations, [which are] characteristic of the BL Lacertae objects, have been observed in M87.
  • Regarding spelling out numbers, I am not familiar with what suggestions the Manual of Style has for scientific numbers, if any, so I won't comment on that. But just to mention, there are a few ",000" (non-spelled "thousand"s) left in the article, like "70,000 times the mass".
  • For the rocket sentence, ok, but again look for way to use non-passive voice (who did what, not what "was done" by whom): "In 1966, the United States Naval Research Laboratory's Aerobee 150 rocket identified the first X-ray source in Virgo, called Virgo X-1." For example.
  • I'm checking just a couple of sources for numbers cited. You write "The mass of M87 within a radius (r)... steadily increases roughly in proportion to r^1.7." The source states that the inferred mass-to-light ratio in solar units increases in that way. Are those the same thing?
The source actually says (in abstract, as well as in body and summary): "M(r)~ r^1.7". Regarding "inferred mass-to-light ratio" it just says that it increases from 5 to 30 when you go from r=9 to r=40 kpc. UbedJunejo (talk•cont) 15:13, 4 May 2018 (UTC)[reply]

Otherwise I am good with everything above that you have responded to so far. Mostly done! I will take another look at the article to see if I'm ready to support. In the future, before a nomination, asking someone to copyedit (I don't know if this was done), such as at WP:GOCE, would help. There are good lessons here that among other things show how to simplify sentence wording, which was a problem for this article. I mention this only to help; the more you can build these ideas into your own writing, the easier FAC is, and the more people will read the article, especially technical articles. :) Outriggr (talk) 01:02, 4 May 2018 (UTC)[reply]

Thank you :) UbedJunejo (talk•cont) 17:58, 4 May 2018 (UTC)[reply]
  • In the "enclosed mass" table, seems like "radius" should be on the left and mass on the right because mass is the dependent variable (as done in the cited source's [Cohen et al] tables). Outriggr (talk) 22:45, 4 May 2018 (UTC)[reply]
Yes, great idea. How can you spot so many things ;) Done.
  • Hi again... can you explain how right ascension and declination in the infobox are obtained from the source [1] "On radio source selection to define a stable celestial frame". This will be my last question/comment... Outriggr (talk) 23:37, 7 May 2018 (UTC)[reply]
Hi, welcome back ;) M87 is no. 145. Glad to hear that :D --UbedJunejo (talk•cont) 00:53, 8 May 2018 (UTC)[reply]
OK. Citation 1 is a journal citation though. Neither of the DOI/bibcode links don't go the page you specified...? I got a PDF out of one, and an abstract etc from the other. Fix? Outriggr (talk) 01:35, 8 May 2018 (UTC)[reply]
I see that [5], "Tables at CDS" is the way there... Outriggr (talk) 01:36, 8 May 2018 (UTC)[reply]
Yes and that link is also present in the pdf you are referring to.--UbedJunejo (talk•cont) 01:53, 8 May 2018 (UTC)[reply]
My point is that the reference should be updated e.g. to reflect the most exact source of the numbers cited. Whatever. Outriggr (talk) 02:31, 8 May 2018 (UTC)[reply]
Hi, yes I understand, but it was not obvious to me how to actually do that, and then I saw you your edit; great. Thank you;)UbedJunejo (talk•cont) 13:39, 8 May 2018 (UTC)[reply]

Closing comment

edit

The last sentence of the forth para of the Jet section is uncited. As it appears to be a general and probably uncontroversial statement, I won't hold up promotion over it, but given this is an FA and not all its readers (including me) are familiar with such things, I'd like to see it sourced. Cheers, Ian Rose (talk) 16:35, 12 May 2018 (UTC)[reply]

The above discussion is preserved as an archive. Please do not modify it. No further edits should be made to this page.
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