Talk:Galaxy

Bananas

I just reverted an edit based on this New Scientist article:

• Banana-shaped galaxies are helping unpeel the mysteries of dark matter: Astronomers have been spotting strange banana-shaped galaxies and the evidence seems to indicate that filaments of dark matter make them take this shape By Alex Wilkins= 5 August 2024 https://www.newscientist.com/article/2442369-banana-shaped-galaxies-are-helping-unpeel-the-mysteries-of-dark-matter/

New Scientist is very uneven and often simply wrong, as in this case.

The primary references behind the New Scientist article are:

• Pozo, Alvaro, et al. "A smooth filament origin for prolate galaxies" going bananas" in deep JWST images." arXiv preprint arXiv:2407.16339 (2024).
• Pandya, Viraj, et al. "Galaxies going bananas: inferring the 3d geometry of high-redshift galaxies with JWST-CEERS." The Astrophysical Journal 963.1 (2024): 54.

The first is unpublished and the second one 11 citations. The 'bananas' bit comes from Pandya:

• "The prolate population traces out a "banana" in the projected $b/a{\text{--}}\log a$ diagram with an excess of low-b/a, large $\log a$- galaxies.

Thus there are no "banana-shaped galaxies" here to "unpeel".

In addition Pandya et al's analysis is simply too new for an encyclopedia. Once we see reviews that cite the work we can reference them and include the topic where appropriate. Johnjbarton (talk) 23:38, 11 August 2024 (UTC)

Use of narrow gaps instead of commas as thousand separators in science articles

The Manual of Style states that, when writing large numbers, grouping of digits using narrow gaps (obtained by using the template {{gaps}}) is “especially recommended for articles related to science, technology, engineering or mathematics”. This is due to the fact that it's the normalized way in the international standards (ISO/IEC 80000 and International System of Units), and also it's the recommended style by ANSI and NIST.

Proposal: Format numbers with gaps -proposed change- instead of commas -the current format- (for example, "100000 parsecs" instead of "100,000 parsecs").

Note: I open the proposal since I did the change myself and @Remsense reverted the editions with the message "because i actually did look at the MOS". I'm afraid that Mr. @Remsense did not look at the MOS carefully enough, but I do not want to open an edition war.

Thanks. RGLago (talk) 18:20, 11 November 2024 (UTC)

I see that you're starting to open up a lot of these requests. I suggest opening a discussion on Wikipedia talk:WikiProject Astronomy to make it more centralised rather than repeating the same words for each astronomy-related article. _ZZ^Z'S 18:24, 11 November 2024 (UTC)

The relevant Manual of Style content seems to be Wikipedia:Manual_of_Style/Dates_and_numbers#Grouping_of_digits. It says

• "This style is especially recommended for articles related to science, technology, engineering or mathematics, though in these contexts there may be cases in which grouping confuses rather than clarifies." and "Either use commas or narrow gaps, but not both in the same article."

Contrary to the post here, the MOS says nothing about ISO, SI, ANSI or NIST in relation to these gaps.

I agree that this issue should be discussed on the Wikiproject page. Johnjbarton (talk) 18:31, 11 November 2024 (UTC)

Etymology

I recently removed content related to the etymology of "Milky Way" which is discussed at length on Milky Way#Etymology. In my opinion the etymology of galaxy is clearer without this material. The modern word "galaxy" is not related to milk, but rather to an astronomical object which had an ancient name involving milk. The notable aspect of the naming was the generalization from one familiar object to the new ones found by astronomy. Johnjbarton (talk) 15:06, 18 April 2025 (UTC)

Number of stars

"Galaxies, averaging an estimated 100 million stars," in the introduction must be incorrect, also in the reference. They probably mean 100 Billion, but I can not find a good source. Most calculations that I find on the internet take our own galaxy as an example of an average galaxy with something like 100 billion stars. Keesal (talk) 09:15, 14 July 2025 (UTC)

Is it possible is still true with all the new very sparse satellite galaxies being discovered? Sagittarian Milky Way (talk) 13:34, 23 July 2025 (UTC)

The billions value is true for large galaxies like the Milky Way, but most are dwarf galaxies. Perhaps we need more references? Praemonitus (talk) 14:47, 23 July 2025 (UTC)