Talk:WikiJournal of Science/Submissions/Alpha Centauri

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From v:Talk:WikiJournal of Science/Submissions/Alpha Centauri:

Please comment on this article. Would it be appropriate for an introductory astronomy course for non-science majors?--Guy vandegrift (discusscontribs) 08:42, 7 February 2016 (UTC)

Wikipedia GA review[edit]

The following is all that remains from the Wikipedia GA review w:Talk:Alpha Centauri/GA1 apparently not addressed:

I've only just taken a quick look. The first thing that caught my eye was the "Alpha Centauri AB distance estimates" section. The presence of the table seems to lack context and I'd like to see a brief text introduction. A casual reader might wonder: why is the table here and what does it mean in plain English. Searching the text I saw "As the stars of Alpha Centauri approach us, the measured proper motion and trigonometric parallax slowly increase." Including a table like this implies to me that it illustrates some significant trend over time, but the data doesn't support the text statement. --mikeu talk 01:09, 19 January 2016 (UTC)

The stellar distance estimates tables have been discussed before, and opinions were mixed. The data is a direct reflection of the improvements in parallax measurement technology and doesn't tell the reader anything useful about the star system itself. A few people seem to find them of value; I don't. Praemonitus (talk) 21:00, 27 January 2016 (UTC)

The "View from this system" and "View from a hypothetical planet" sections seem a bit long and lack citations. Have these topics been discussed at length in reliable sources? Is the material notable enough to warrant extensive discussion in the article? Those are longer than "Observational history" which contains more important information (early parallax measurements) giving these sections undue weight to a topic of more trivial importance. --mikeu talk 02:10, 19 January 2016 (UTC)

A review of Alpha Centauri[edit]

Wow! There's a lot of information in this article. Very detailed and with apparently one exception (citation needed) well referenced. This is unusual for Wikipedia. The image was missing from the permalink article. Not sure why. The number of possible quiz questions is enormous. The view of the stars from a planet around the binary or one of them seems okay but difficult to check. I believe most of the information was obtained by visual astronomy except for some of the planet searching. Proxima Centauri is a significant X-ray source for its size. Kinda curious why Proxima Centauri is an FA but this one is not. At 87 kB this is a pretty good sized lecture with only ten content sections. My guess is that a non-science major in an introductory astronomy course would have a brain freeze over all the detailed numbers. --Marshallsumter (discusscontribs) 04:15, 28 March 2016 (UTC)

Editorial comments:

  1. The sentence ending with "and the Hubble Space Telescope[32]" needs a period (.).
  2. Needs another one at the end of "red circle is Proxima Centauri". --Marshallsumter (discusscontribs) 15:55, 27 May 2017 (UTC)
  3. "To be in the star's habitable zone, any suspected planet around Alpha Centauri A would have to be placed about 1.25 AU away [citation needed]" has not been addressed since 15 September 2014. --Marshallsumter (discusscontribs) 16:39, 27 May 2017 (UTC)
  4. "Alpha Centauri A (α Cen A) has 1.1 times the mass and 1.519 times the luminosity of the Sun, while Alpha Centauri B (α Cen B) is smaller and cooler, at 0.907 times the Sun's mass and 0.445 times its visual luminosity.[13]", the visual luminosity of Alpha Centauri B does not match the value from [13]. --Marshallsumter (discusscontribs) 13:55, 24 May 2017 (UTC)
  5. "Although it has a lower luminosity than component A, star B emits more energy in the X-ray band." needs a citation. --Marshallsumter (discusscontribs) 17:29, 27 May 2017 (UTC)
  6. "Alpha Centauri C, also known as Proxima Centauri, is of spectral class M6 Ve, a small main-sequence star (Type V) with emission lines. Its B−V colour index is +1.82 and its mass is about 0.123 solar masses (M☉), or 129 Jupiter masses." The citations for these facts are in the w:Proxima Centauri article and should be included here.
  7. "Using spectroscopy the mean radial velocity has been determined to be around 20 km/s towards the Solar System." needs a citation.
  8. If the citation at the end also applies to the earlier sentences in this paragraph, please use ref tag or something similar to indicate such for "Based on observations between 2007 and 2012, a study found a slight excess of emissions in the 24 µm (mid/far-infrared) band surrounding α Centauri AB, which may be interpreted as evidence for a sparse circumstellar disc or dense interplanetary dust. The total mass was estimated to be between 10−7 to 10−6 the mass of the Moon, or 10-100 times the mass of the Solar System's zodiacal cloud. If such a disc existed around both stars, α Centauri A's disc would likely be stable to 2.8 AU, and α Centauri B's would likely be stable to 2.5 AU. This would put A's disc entirely within the frost line, and a small part of B's outer disc just outside.[118]"
  9. "View from this system" to "Views from this system". --Marshallsumter (discusscontribs) 18:40, 27 May 2017 (UTC)

Suggestions:

  1. Depending on what the authors or submitter want to do, I suggest including an answer to some of the terms in the Wikipedia article, e.g., star - the Sun's photosphere has only one part in 104 plasma so a ball of plasma held together by gravity is limited and may not apply.
  2. What is apparent visual magnitude?
  3. To compare α Centauri AB with the Sun initially radii would have more meaning.
  4. Except for mentioning Proxima Centauri briefly and the 2017 results proving it does orbit α Centauri AB, leave it out.
  5. What are U - B and B - V colour indices?
  6. Is radial velocity relative to Earth line of sight?
  7. In the article image at the top right there are a lot of stars closer to α Centauri AB than Proxima Centauri, why aren't they part of the system?

--Marshallsumter (discusscontribs) 04:26, 26 May 2017 (UTC)

  1. Although α Centauri B has a cooler photosphere than α Centauri A, how come component B emits more energy in the X-ray band?
  2. How about a lot more information about α Centauri B? --Marshallsumter (discusscontribs) 14:56, 5 May 2017 (UTC)
  3. See Stars/Alpha Centauri B for some more recent parameters. --Marshallsumter (discusscontribs) 04:24, 24 May 2017 (UTC)
  4. I cannot confirm a visual luminosity of 0.445 attributed to Kervella 2003, apparent visual magnitude of −0.27, Apparent magnitude of 1.33, U−B colour index of +0.68, or B−V colour index of +0.88. --Marshallsumter (discusscontribs) 04:05, 26 May 2017 (UTC)
  5. "Alpha Centauri is inside the G-cloud," could use a brief description of the w:G-Cloud and its diagram which includes α Cen.
  6. Reduce the w:Alpha Centauri#Proxima Centauri section down to focus on Kervella results confirming Proxima is in orbit around A & B.
  7. "Relative positions of Sun, Alpha Centauri AB and Proxima Centauri. Grey dot is projection of Proxima Centauri, located at the same distance as Alpha Centauri AB." doesn't make sense. Why not leave it as "Grey dot is location of Alpha Centauri AB,"? --Marshallsumter (discusscontribs) 18:40, 27 May 2017 (UTC)

Second review[edit]

The above section: A review of Alpha Centauri indicates the articles shortcomings. I recommend against publication until these concerns are appropriately addressed. --Marshallsumter (discusscontribs) 15:52, 1 May 2017 (UTC)

Perhaps w:WikiProject Astronomy or w:WikiProject Astronomical objects should be contacted for responses and changes to the article to comply with the reviews. --Marshallsumter (discusscontribs) 18:46, 27 May 2017 (UTC)

Alpha Centauri review[edit]

@Marshallsumter: I was called over here to look at the provided article? Apologies, but I am not too experienced in wikiversity. What am I needed for exactly? Exoplanetaryscience (discusscontribs) 00:02, 7 June 2017 (UTC)

@Exoplanetaryscience: Thank you for responding! The above comments, suggestions, and criticisms by me and the other reviewer are here in an effort to improve the article w:Alpha Centauri as it appears on Wikipedia so that a specific revision or the current one becomes an article in the WikiJournal of Science if accepted. Please feel free to go over the above comments and either modify the article where you and other authors deem appropriate or comment contrarily. I will try to answer any questions that you and others have! --Marshallsumter (discusscontribs) 00:19, 7 June 2017 (UTC)