Did You Know?........Betelgeuse Might Not Be There....

[ToraToraTora]

....Betelgeuse is a red giant star approx 640 light years away. It is about to go Supernova and there is a good chance it already has. We see it as it was 640 years ago.

[10ClarionSt]

I don't think so, TTT. I read about this some time ago. I like my astronomy. I have a 10" Celestron Nexstar (Oo Mrs!).
Seems that it was covered with lots of, what we call, sunspots. See here:
https://www.bbc.co.uk/news/science-environment-53218658

[ToraToraTora]

Yes 10cs, probably is still there. This sort of stage of a star can last 100,000 years so you are probably correct but it may have gone. The most famous of a recent Supernova is actually on the Bayeux Tapestry, reports of the time (1054) say it was visible in day light. The remnants are known as the Crab nebula. It would be a spectacular sight in the sky if it does go.

[douglas9401]

Pretty much covered the whole spectrum of possibilities in three posts there.

Well done.

[Bazile]

Given the huge number of stars in the milky way alone (never mind the huge number of galaxies out there ), how many supernovas do we actually know about ?

Is a SN an extremely rare event ?

[douglas9401]

Rare enough to call for champagne, apparently.

[THECORBYLOON]

Was it not Halley's comet on the Tapestry?

[Etch]

The Bayeux Tapestry records a supernova? PMSL, everyone with an ounce of astronomical knowledge knows that it shows Halley's Comet, visible in 1066.

[Kardashev]

They are relatively common but most are so far away that we only know via astronomers etc. Type 1a Supernovas are very useful to astronomers because they can help accurately measure distances.

[THECORBYLOON]

"SN 1054 is a supernova that was first observed on c. 4 July 1054, and remained visible until c. 6 April 1056."

[royfromaus]

Give it up.

[jno]

I was wondering if anyone had ever seen TTT and Kardashev in the same room...

[ToraToraTora]

yes apologies senior moment it was Halley's Comet.

[royfromaus]

yes apologies senior moment it was Halley's Comet.
______________________________

That sentence didn't end like I thought it would.

[Gromit]

It would be ironic if it went out just as the James Webb was switch on.

[Togo]

Some sources are predicting that the binary star KIC 9832227 could go supernova as soon as 2022. That will be some event.

https://www.dailymail.co.uk/sciencetech/article-4091604/Mark-calendars-dazzling-supernova-appear-sky-2022-predict-astronomers.html

[Bazile]

It won't go supernova in 2022 , will it .

It will have already gone supernova

[jno]

it has been hiding its light under a bushel, Bazile

[Togo]

This must find a home on this thread Tora.

https://www.msn.com/en-gb/news/world/supergiant-star-explosion-seen-live-by-astronomers-in-unprecedented-breakthrough/ar-AASuUci?li=AAnZ9Ug

[Togo]

For the pedants who insist on stating the bleedin obvious.

"It happened 120 million years ago. The star was located in the NGC 5731 galaxy about 120 million light-years away from Earth."