Betelgeuse dimming

[Stu]

With all the cloud and rain around lately I've not seen this, but has anyone else noticed Betelgeuse dimming just lately? Some relevant links here. Seems it is not related to it going SN but still is at its dimmest for approx 50 years.

Some relevant links here, please do post up if you have noticed this or have any brightness estimates yourself.

http://www.astronomerstelegram.org/?read=13341

https://www.google.com/amp/s/amp.iflscience.com/space/betelgeuse-is-fainting-but-its-not-about-to-explode-probably/

[Mr Spock]

It will be expanding and therefore going infra-red. Is anyone measuring that?

[tooth_dr]

I’ve noticed this too and I’m a non observer.  It’s just not as vibrant. I show my kids Orion any time it’s clear so that’s how I’ve seen it 

[michael.h.f.wilkinson]

Not too surprised. Many red giants are semi-regular long period variable stars. Not likely to be the the herald of anything spectacular

[Skipper Billy]

48 minutes ago, michael.h.f.wilkinson said:

Not too surprised. Many red giants are semi-regular long period variable stars. Not likely to be the the herald of anything spectacular

I know you are right, but I SO hope you are wrong 😉

 

 

[Clear Skies!]

51 minutes ago, michael.h.f.wilkinson said:

Not too surprised. Many red giants are semi-regular long period variable stars. Not likely to be the the herald of anything spectacular

I agree.

If you doubt: Wikipedia. Look on the right in the Starbox. Find "Variable star type". It says: SRC. Click on it. You will come to page Semiregular variable star.

 

Clear skies

[Stu]

I think the relevant point was not that it's a variable star but that it is apparently at a 50 year low in terms of brightness.

[andrew s]

6 hours ago, Mr Spock said:

It will be expanding and therefore going infra-red. Is anyone measuring that?

If you go to the AAVSO web site and their "Light Curve generator" and plug in "alf ori" it will plot the light curve which does show it dimming slightly. If you plut in say 1200 days you can see its variations and that it is just slightly lower than previous minima.

Regards Andrew 

Edited December 20, 2019 by andrew s

[Sunshine]

I have spent much time imagining how incredible it would be to witness Betelgeuse finally blow up. Imagine it happened as you were out observing, i would certainly fall on my rear with excitement.

I would be that guy who creates a huge ruckus and, wakes the entire neighbourhood from my backyard,  i cant wait, please let it happen in my lifetime. How lucky we would all be.

[DaveS]

Tick tock goes the clock.....

[kirkster501]

I don’t want it to explode. Imagine Orion without Betelgeuse!

i have also noticed it is fainter this year.

[maw lod qan]

54 minutes ago, Sunshine said:

I have spent much time imagining how incredible it would be to witness Betelgeuse finally blow up. Imagine it happened as you were out observing, i would certainly fall on my rear with excitement.

I would be that guy who creates a huge ruckus and, wakes the entire neighbourhood from my backyard,  i cant wait, please let it happen in my lifetime. How lucky we would all be.

These are my thoughts as well. Seems almost every morning when I leave for work, I look up and say good morning to "the old man".

[david_taurus83]

When it does go, I can guarantee it will be UK summertime and cloudy for weeks.

[Highburymark]

Though if it explodes (or should I say if it already exploded 500-600 years ago) it should also be visible during daytime. What a sight that would be. 

[Ovi]

Now that I think about it, Betelgeuse really looks like it's dimming. I remember it being almost as bright (if not as bright) as Rigel. Now it looks like Rigel is twice as bright. I've sent quite some time wondering how it would look if Betelgeuse went supernova although it's quite unlikely it will in our lifetime

[Ouroboros]

I've wondered that too. Also how it would look if you happened to be looking at it at the moment it went supernova. Would it instantaneously turn on like a bright light or is it a gradual process? Has anyone ever been observing a star when it became a supernova, or have they only been observed post nova?  

I too noticed Orion recently and thought Betelgeuse looked a little less than its usual bright self. I didn't really think anymore about it so it's interesting to read that it is dimming. 

[Rob Sellent]

From my understanding it takes a good few millions of years for a large mass star to gradually die, less than a quarter of a second for its core to collapse, perhaps a couple of hours for that shockwave to reach the outer layers of the star, a few weeks to months to brighten as a Supernova, and then it just fades away with time. I recall observing the supernova in Messier 82 a few years back but can't remember it staying bright in the sky for long. With the 10" in action if I said it lasted a few weeks, I don't think I'd be that far out.

Anyway, here's an amazing extract of the death of a star like Betelgeuse:

 

[Stu]

Just had a look at this, skies unexpectedly clear. It looked a little dimmer than Aldebaran which is mag 1.0 and brighter than Bellatrix which is mag 1.7. That gives an estimate roughly in line with the mag 1.12 quoted in the first link. Skysafari still lists it at mag 0.6

[Alien 13]

If it goes bang what would be the best way to view it as it could be many times brighter than a full moon? 

Alan

[DaveS]

Probably with a spectrograph, as that's about the only thing that will give you useful information until the blast shell gets big enough to give a worthwhile image. But when it does get big enough (After the main flash has dimmed) then every camera that can point at it will be pointing at it.

[Tris]

I read somewhere that it could be brighter than a full moon for a year! If so, then while spectacular, it would prevent a lot of visual astronomy. 

[johninderby]

Nope. Too far away. Would have to be within 50 - 100 light years for damaging levels of radiation and it’s 642 light years away.

[JeremyS]

42 minutes ago, KevS said:

Would we all be bombarded with some sort of deadly radiation if it went west? 

There is a discussion on this subject on the BAA website Forum here.

[andrew s]

There is also a nice article by @JeremyS on it under the "Articles" tab on the BAA website.

Regards Andrew 

[Paul M]

I seem to remember that the core collapse is momentary and the neutrinos generated in that moment are the first indicator of the collapse, before the outer shell of the star is blown away and illuminated by the intense radiation, the neutrinos are already heading towards your backyard neutrino detector.

Every serious supernova hunter has a neutrino alarm, don't they?