Did Betelgeuse change colour?

[JeremyS]

According to this paper it did, some 2,000 years ago it was not red: https://arxiv.org/abs/2207.04702

The authors claim this is observational evidence of stellar evolution in action.

 

[Alan White]

I have no idea about the science time line, but 2000 years is but a blink of the eye in the Cosmos,
So somehow I have my doubts on this finding based on gut instinct.

Clearly the data set of two observers feels unreliable to add to my reasoning.

Clearly I could be way off the mark through ignorance.

Edited July 12, 2022 by Alan White

[Mr Spock]

Wouldn't the kind of change they are suggesting also change the luminosity?

[ONIKKINEN]

Remember a few years ago Betelgeuse was dimming significantly? But now it seems to be up and running again. It could be perceived as less red if it dims significantly, at least i think that is the case when looking at Mars in opposition or when further away. I think that dimming event a few years back was due to some ejecta from the star forming a sort of dimming cloud around the star or something like that.

2000 years is also not that short for a massive star like betelgeuse and that could be enough time for a change in temperature along its natural stellar evolution path. 2000 years is also long enough to make it rather difficult to check the sources 😆, so could be or could not be right.

 

[newbie alert]

It's a known variable star... It will dim quite significantly as it did a few years ago..  think it's been talked about going supernova since my early childhood.. one one hand it be great to see that happen, but on the other we lose that iconic star

[catburglar]

Whilst brightness variations may affect the perception of colour, to me this seems like it could represent evidence of a real colour change.

Irrespective of brightness, Mars, Jupiter and Saturn all appear very different colours to my unaided eye, so the comparison that Betelgeuse was similar to Saturn seems unlikely to arise simply because of poor perception of colour on behalf of the observers- although I accept that stranger observations have been recorded throughout the history of astronomy…