Talk:Andromeda Galaxy

In Fiction

• Star Trek: TOS, a alien empire comes to conquer this galaxy.

UFO Lore

• Home of the Andromedan aliens, who have (allegedly) ordered all other aliens OFF of Earth and OUT of the Sol star system.

65.173.105.27 (talk) 04:34, 9 July 2008 (UTC)

Can someone add these? I can't, since the article is protected.65.173.105.27 (talk) 04:35, 9 July 2008 (UTC)

Fictional information of this nature can be added to Galaxies in fiction, which is linked from the "See also" section.—RJH (talk) 17:59, 11 July 2008 (UTC)

Different

The apparent magnitude of the Andromeda Galaxy is given as 3.4 and 4.4. The latter seems to be correct. —Preceding unsigned comment added by 93.97.55.83 (talk) 10:13, 6 September 2008 (UTC)

we should talk about how this galaxy will collide with the milky way

in the opening paragraph. Fourtyearswhat (talk) 19:36, 19 September 2008 (UTC)

Well, because that would mean the end of the milky way galaxy.--Jakezing (talk) 02:12, 7 November 2008 (UTC)

It'll be the end of Andromeda Galaxy, as Milky Way will swallow Andromeda Galaxy, Milky Way is about 40% larger than Andromeda Galaxy...THIS IS WRONG

  —Preceding unsigned comment added by 88.109.209.213 (talk) 01:35, 15 April 2009 (UTC) 

Per WP:LEAD, the lead section is intended as a summary of the main article. The body contains a paragraph on the topic, so I think it deserves at most a sentence in the lead. Most of the material on the subject is now on the Andromeda-Milky Way collision article.—RJH (talk) 16:06, 7 November 2008 (UTC)

Closest galaxy?

I've always thought that andromeda was the closest galaxy to our own, but the intro implies that it is merely the closest spiral galaxy to ours. Can someone verify this? Thanks! M00npirate (talk) 01:31, 16 December 2008 (UTC)

The Magellanic Clouds, for example, are much closer. See Local Group.—RJH (talk) 20:59, 16 December 2008 (UTC)

It's the closest galaxy to ours that is of a comparable size to ours, there are plenty of smaller ones nearer. --Tango (talk) 21:01, 16 December 2008 (UTC)

Some editor is not only misinformed about Hipparcos results, but believes EVERYONE ELSE is misinformed

Article currently states that Hipparcos either did not measure Cepheid variable-star distances with reasonable accuracy- or did not measure ANY CEPHEIDS AT ALL. Several dozen Cepheids fell within HIpparcos' effective range of ~100 parsec (a few hundred light years). Of those, a dozen or so were quite close, measured with strong S/N multiple times.

One possibility is that some editor is so grossly ignorant of distance measurement that she believes Hipparcos must measure Cepheids located inside Andromeda. This is, frankly, a shocking degree of misinformation. A quick read of the Hipparcos or Cepheid articles will illustrate the measurement method, but I'll summarize just to be thorough. Hipparcos CALIBRATES Cepheid distances; Andromeda Cepheids can then be observed with HST, Keck I/II, Gemini N, etc. —Preceding unsigned comment added by 12.176.210.201 (talk) 00:03, 7 June 2009 (UTC)

I've removed both the uncited mention of 2.9 million light years and the dubious tagged stuff. 84user (talk) 11:26, 11 June 2009 (UTC)

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

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GA Reassessment

This discussion is transcluded from Talk:Andromeda Galaxy/GA1. The edit link for this section can be used to add comments to the reassessment.

GA review – see WP:WIAGA for criteria

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This review is part of Wikipedia:WikiProject Good articles/Project quality task force/Sweeps, a project devoted to re-reviewing Good Articles listed before August 26, 2007.

1. Is it reasonably well written?

   A. Prose quality:

   "The nucleus is double," poor wording. "It also should be noted that the galaxy" redundant phrasing. The article is good in most areas, but there are some parts that need work.

   B. MoS compliance:

2. Is it factually accurate and verifiable?

   A. References to sources:

   B. Citation of reliable sources where necessary:

   While parts of the article maintain a high number of references, there are many uncited statements, and the whole table at the bottom is unreferenced. There is one {{citation needed}} tag, and I could add more.

   C. No original research:

   Uncited statements may contain original research.

3. Is it broad in its coverage?

   A. Major aspects:

   B. Focused:

4. Is it neutral?

   Fair representation without bias:

5. Is it stable?

   No edit wars, etc:

6. Does it contain images to illustrate the topic?

   A. Images are copyright tagged, and non-free images have fair use rationales:

   B. Images are provided where possible and appropriate, with suitable captions:

   Images are great, very informative and high quality.

7. Overall:

   Pass or Fail:

   References are a big issue, this article must maintain a solid base of references to keep GA status. Article will be placed on hold until issues can be addressed. If an editor does not express interest in addressing these issues within seven days, the article will be delisted and reassessed as B-class. --ErgoSum•talk•trib 22:03, 7 July 2009 (UTC)

I addressed the main concerns regarding citations, though part of that included removing the table, as I can see no reason for an arbitrary portion of the table on the main page about Andromeda's satellites to have been copied on to the page for Andromeda. I'll try to address the issue of citations there anyway, but I think the main concerns you raised for the article as it stands have been addressed. James McBride (talk) 09:28, 12 July 2009 (UTC)

I will have to give it one more review to spot any further problems, but it looks much better. Give me some time to make another assessment and I will let you know. --ErgoSum•talk•trib 15:46, 12 July 2009 (UTC)

I believe there is one more statement that needs a ref. Other than that, all other issues have been addressed. --ErgoSum•talk•trib 18:03, 12 July 2009 (UTC)

Okay, done. James McBride (talk) 21:44, 12 July 2009 (UTC)

Nice work. All issues have been addressed, article will be kept. --ErgoSum•talk•trib 21:49, 12 July 2009 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Name of the object in this article

I can't back this up with any sources, but i learned that this object was origanlly named "great nebula in andromeda" and later "galaxy in andromeda". Also, it is the constellation in which this object is located that is named after the princess in greek mythology, not the object discussed here itself. maybe i'm wrong here, but i think it should at least be looked into.

92.116.36.115 (talk) 04:28, 1 January 2010 (UTC)

Observation history

This claim is false "The Roman poet Avienus wrote a tantalizing line about the chained constellation in the 4th century AD.[14] who described it as a "small cloud" in his Book of Fixed Stars." Avienus never said that, it was in fact Abd al-Rahman al-Sufi. Even if you click on the link of the book, it states that HE is the author and HE is the one quoted saying that. Check other sources as well. I will make the correct change. (Parmis17 (talk) 08:05, 14 November 2010 (UTC))

Alternative lead picture:

Current

New image

I just imported this excellent picture (bottom image on right) from Flickr, and wondered whether anyone objected to using it as the lead image in the article. It's of a higher resolution, has a wider field of view and is more aesthetically interesting than the one we're using at the moment. However, it includes h-alpha, so thought it would be sensible to propose the change here first in case there is consensus that the current version has more encyclopedic value. NotFromUtrecht (talk) 20:42, 10 January 2011 (UTC)

Go for it; I like it. -- cheers, Michael C. Price ^talk 08:47, 11 January 2011 (UTC)

Either is ok for me. Casliber (talk · contribs) 09:39, 11 January 2011 (UTC)

I vote for the lead being more like what is seen with a simple telescope.Cesiumfrog (talk) 06:05, 30 January 2011 (UTC)

I am just wondering why this image had not been flipped? it is showing Andromeda how it appears through an uncorrected Telescope. do we print pictures of people upside down when taken through a lens? no we correct them and print the image so it looks as it should to the human eye. you have over 100 pages linking to this image and if you look at the image below (above on the main page) on this page you will see you have 2 images of Andromeda, one corrected and the other not its traveling in 2 different directions, one will miss the milky way, then other will collide with it in 4.4 billion years. Samantha.pia (talk) 17:01, 11 April 2011 (UTC)

elegant distance measurement

In 1922 Ernst Öpik presented a very elegant and simple astrophysical method to estimate the distance of M31.

This line of the article is possibly plagiarised. More importantly, where can we find a description of this elegant and simple method (which supposedly was far more accurate than Hubble's and is still used)? Cesiumfrog (talk) 06:10, 30 January 2011 (UTC)

The argument can be found here - not difficult to find. https://www.cfa.harvard.edu/~huchra/ay202/opik.pdf And here: [1] I can't tell how good it is. Myrvin (talk) 08:19, 30 January 2011 (UTC)

Britannica says "In 1922 Öpik proved that the source of stellar energy was nuclear and heavily dependent upon temperature. At this time he also made an estimate of the distance of the Andromeda Nebula that was still valid a half century later." Myrvin (talk) 08:24, 30 January 2011 (UTC)

Rotational velocities must be wrong

(quote from the article): rotational velocity climbs to a peak of 225 kilometres per second (140 mi/s) at a radius of 1,300 light-years (82,000,000 AU), then descends to a minimum at 7,000 light-years (440,000,000 AU) where the rotation velocity may be as low as 50 kilometres per second (31 mi/s). (end quote)

If one calculates the accelleration at 1,300 lightyears which is needed for a roatational velocity of 225 km/s (4,11E-09 m/sec2) the mass wich would cause this is 9,34E+39 kilo~ If one calculates the acceleration this mass causes at 7,000 lightyears one gets 1,42E-10 m/sec.

If however one calculates the acceleration at 7,000 lightyears for a rotational velocity of 50 km/s this is only 3,77E-11 km/sec2, 25% of what it should be. Do we have negative dark matter here, or has someone messed up the data? I suspect the latter Velzen5 (talk) 11:25, 27 March 2011 (UTC)

I think your calculations are done using an assumption of spherical symmetry (using the shell theorem). The galaxy is actually disc shaped, which might change things. I don't think you can model the gravitational field of a disc as the gravitional field of a point mass of the same total mass, the way you can with a ball. That said, I think your calculation contains an error that means it understates the problem - you have neglected the mass that exists between 1,300 ly and 7000 ly. That extra mass should compensate for some of the extra distance, giving faster rotational speeds. --Tango (talk) 12:02, 27 March 2011 (UTC)

Velzen, have you looked into this at all: [2] ? Cesiumfrog (talk) 22:45, 27 March 2011 (UTC)

Active Nucleus

The gxy has an active galaxy nucleus (AGN - Y1O-TLA) per SIMBAD and per Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010) (at VizieR). More specifically it is a "LINER-type Active Galaxy Nucleus" (or whatever) acc2 SIMBAD. FYI. Rursus dixit. (^mbork³!) 13:34, 4 April 2011 (UTC)