Betelgeuse merged with another star

[Damien1975]

https://ui.adsabs.harvard.edu/abs/2017MNRAS.465.2654W/abstract

https://ui.adsabs.harvard.edu/abs/2020AAS...23513106C/abstract

https://www.aavso.org/apps/webobs/results/?star=BETELGEUSE&num_results=200

came across this 

Edited February 8, 2020 by Damien1975

[Sunshine]

From what I gather, this person is saying that an explanation for Betelgeus' high rotational velocity would be a past merger with a smaller star during its bloating stage?. They have done computer models demonstrating this merger and, the end result was Betelgeuse having an uncharacteristically high rotational speed?

I am not a physicist but, my issue with this is, do we really know what b's rotational speed is?? its distance is up for debate to within 500 LY's or so. I would like to know if it's rotational speed has been measured and, to what accuracy?

[andrew s]

If you Google rotation  of betelgeuse you will get lost of links to explain it's rotation.

Its normally measured via spectroscopy but betelguse is so large it can be imaged via interferometry. 

Regards Andrew 

[Damien1975]

So what would happen if it became a black hole instead?

 

also why is the date feb 21 important for this 

[Islander]

16 minutes ago, Damien1975 said:

So what would happen if it became a black hole instead?

 

also why is the date feb 21 important for this 

Why would a stellar merger become a black hole?  Also, where did the date pop up from?

I'm really not sure what you're looking for...

[Damien1975]

6 minutes ago, Islander said:

Why would a stellar merger become a black hole?  Also, where did the date pop up from?

I'm really not sure what you're looking for...

No it’s a new notion that because of the unordinary dimming it May become a black hole 

[Islander]

No, it really isn't.  The more sensationalist press might run with that but it's not mainstream scientific opinion.

Red supergiants are inherently variable.   Betelgeuse has dimmed somewhat but that's likely to be caused by material being expelled, again a feature of red supergiants.