Talk:Betelgeuse

Further evidence for companion

The article now (again) presents the companion as confirmed, based on a NASA press release which says as much. Yet the new paper still uses less certain wording: The occurrence and variation of this plasma appear consistent with the presence of a trailing and expanding wake caused by a companion star orbiting within the atmosphere of Betelgeuse; If the postulated and probably-detected companion to Betelgeuse is confirmed...

Siwarha is certainly a strong candidate with multiple lines of evidence (and an IAU name), but should we present it as confirmed? In any case the new evidence should be discussed in the "Companion star" section, not just in the lead. SevenSpheres (talk) 01:47, 6 January 2026 (UTC)

Go with the paper rather than the press release. Renerpho (talk) 01:52, 6 January 2026 (UTC)

Agreed. The same situation happened with that 'direct imaging' discovery, on which the press releases claimed the companion to be a fact carved in stone, but in reality was just an 1.5-sigma discovery. We shouldn't present the companion as confirmed when all the papers only point to evidences and none claim the companion as a fact. 21 Andromedae (talk) 16:10, 6 January 2026 (UTC)

it looks like this new paper https://www.eso.org/public/archives/releases/sciencepapers/eso2611/eso2611a.pdf in my opinion would be confirmation at 6.1 sigma although the authors are more restrained in their conclusion ~2026-42007-90 (talk) 07:37, 29 July 2026 (UTC)

Mittag et al. (2023)

This paper does not pick a radius but instead describes the radius changing over time during the dimming event. It seems the value of 640 R_☉ was just slapped into the starbox without an understanding of the context behind said value. Specifically, 640 R_☉ was the radius of the star before the dimming event if you look at figure A.1 and A.2, the radius does not return to the same size as before. Faren29 (talk) 17:56, 28 January 2026 (UTC)

The last points of both figues (after the dimming and subsequent increase in radius) are located at roughly 650 R_☉, so the radius return to the original state. 21 Andromedae (talk) 11:23, 29 January 2026 (UTC)

Shariat et al. 2026

This paper about long secondary period variables (currently at the preprint stage) has some discussion of Betelgeuse's binarity. In the conclusion: Given that Betelgeuse shows an RV amplitude, photometric amplitude, period, and implied mass ratio typical of the broader LSP population, our results suggest that its LSP may likewise arise from an alternative physical mechanism rather than from orbital motion due to a binary companion, although it may represent a special case. SevenSpheres (talk) 16:26, 14 April 2026 (UTC)

Answered by Iwanek et al. 2026. 21 Andromedae (talk) 15:23, 28 July 2026 (UTC)

It resides in our galaxy, the Milky Way

Is it truly necessary to point out in the 2nd sentence of the lede that Betelgeuse is in the Milky Way galaxy (as added by Reid1801 in Special:Diff/1352110775 today)? I don't see similar statements in any other article about individual stars, like the featured articles Sirius or Vega; not even those about stars that are much more distant than Betelgeuse (i.e., Eta Carinae). Renerpho (talk) 03:34, 2 May 2026 (UTC)

I believe it is not necessary. The only cases where we note the galaxy of a star is when it is not in the Milky Way. 21 Andromedae (talk) 13:16, 2 May 2026 (UTC)

Removed. Renerpho (talk) 16:40, 2 May 2026 (UTC)

Mass

According to this ref, the envelope surrounding Betelgeuse contains a mass of only 0.042–0.096 M⊙, so it does not seem to have experienced significant mass loss. Even if the 14 M_☉ value turned out to be the initial mass, it would be quite close to the current value. 21 Andromedae (talk) 13:46, 2 May 2026 (UTC)

Just noticed that the MIST isochrones used in the Neuhauser ref are actually sensitive to the initial mass, so the 14 M_☉ is technically an initial mass, but is likely close to the current mass as i noticed above. 21 Andromedae (talk) 14:18, 2 May 2026 (UTC)

Companion almost confirmed

https://www.eso.org/public/news/eso2611/ - Detected at 6.1-sigma significance; the only thing that remains uncertain is that it's gravitationally bound to Betelgeuse. It's more massive than predicted. This source only calls it Betelgeuse B, not Siwarha. SevenSpheres (talk) 14:49, 28 July 2026 (UTC)

Cool. Already added to the article. But unfortunately the companion is still treated as a candidate by the authors until the companion "is observed on the other side of the primary after half an orbital period", which should take between 2.5 and 3 years since the original image was taken. 21 Andromedae (talk) 15:00, 28 July 2026 (UTC)

@21.Andromedae, I think they are treating it as candidate because once they did that the star would become very known to general public and misinformation might spread, if you know Betelgeuse Supernova related videos. While in general case this type of discoveries are made as confirmed. Abdullah1099 (talk) 07:45, 5 August 2026 (UTC)

I don't think so. Betelgeuse is already well-known. 21 Andromedae (talk) 16:07, 5 August 2026 (UTC)

Another paper about Siwarha, which does use that name in the full text. Finds evidence of perturbation of Betelgeuse's atmosphere by a companion. SevenSpheres (talk) 02:31, 5 August 2026 (UTC)