Betelgeuse will be eclipsed by an asteroid

[mfb]

TL;DR Summary

One of the brightest stars in the night sky will be eclipsed by asteroid Leona December 11/12.

Occultations of bright stars are very rare. In the night to Tuesday (~10 seconds between 01:98 to 01:26 UTC depending on the location) it will be visible in a narrow band starting near Guadalajara in Mexico, crossing Florida at Miami, southern Spain, southern Italy, northern Greece, and Turkey around Ankara before ending in central Asia. This article has maps, more details.

Occultations are great opportunities to study the asteroid in more details, but here astronomers will also use observations to learn more about the star. We know it's approaching the end of its life and it's very dynamic, changing its brightness and even shape notably over time.

 

[Borg]

Definitely a fascinating event. This site will be providing a live stream of the event from Italy on 12 Dec. 2023, starting at 01:00 UTC:
https://www.virtualtelescope.eu/webtv/

From mfb's article above:

Lasting for nearly 18 minutes, the occultation will start at 8:08 p.m. ET and end at 8:26 p.m. ET (December 12 at 01:08:23 UT to 01:26:00 UT).

 

[Vanadium 50]

Occultations are great opportunities to study the asteroid in more details, but here astronomers will also use observations to learn more about the star.

One day I will get the differences between transits, eclipses, and occultations straight. But what will we learn about the star? Onviously we won't see it when it is occulted.

 

[Ibix]

occult

Telling the difference is a black art.

 

[Baluncore]

But what will we learn about the star?

We may learn nothing new about the star, because we now have Hubble images.
The variation in brightness of the star, as it is eclipsed by the asteroid, can be deconvoluted to determine the size and the intensity of the corona.

 

[snorkack]

One day I will get the differences between transits, eclipses, and occultations straight. But what will we learn about the star? Onviously we won't see it when it is occulted.

If and when it were "occulted".
The thing is, like Sun and Moon, Leona and Betelgeuse are actually close in size... with the foreground object thought to be slightly smaller (like annular eclipses of Sun). BUT compared to Sun and Moon which are close to exact discs, Leona and Betelgeuse are BOTH quite distorted, in shape and (what matters for Betelgeuse) distribution of brightness across the face.

 

[DaveC426913]

Man that would be cool to see...

 

[Baluncore]

How often are stars eclipsed or occluded by LEO satellites, bats or aeroplanes?
Was that not a way of tracking stealth aircraft flying over your territory at night?
Blink, and you will miss it.

 

[Vanadium 50]

We may learn nothing new about the star, because we now have Hubble images.

Exactly what I was getting at.

It may be possible to do spectroscopy (if it could be done fast enough) and learn something about magnetic fields, bur I would imagine they are small.

 

[Vanadium 50]

How often are stars eclipsed or occluded by LEO satellites, bats or aeroplanes?

This sounds like a Fermi problem.

For satellites the scale is once per night. Maybe this is a few times per night, and maybe it is once every few nights, but it's not minutes and its not centuries.

However, these events last fractions of a millisecond.

 

[DaveC426913]

Almost two hours past and no updates. No live feeds (virtual telescope cancelled due to overcast conditions).

I dream of a future where international news will travel faster than a guy on a pony with a mail bag. But I'm spoiled.

Guess I'll wait till the world's astronomers punch in tomorrow at 9AM EST...

 

[mfb]

One day I will get the differences between transits, eclipses, and occultations straight. But what will we learn about the star? Onviously we won't see it when it is occulted.

Different parts of the star were blocked from view at different times, which corresponds to an effective angular resolution better than everything conventional telescopes on Earth can provide.
Hubble is too small to contribute to that anyway.

 

[Vanadium 50]

I don't dispute that, but it doesn't answer my question. What do you learn about the star? If you were writing a proposal for telescope time, what would be the title?

 

[mfb]

Map its convective cells, for example.

Not a hypothetical example, telescope time was used for that:
https://skyandtelescope.org/astrono...er-betelgeuse-may-reveal-its-visible-surface/
https://www.scientificamerican.com/...-disappear-in-once-in-a-lifetime-coincidence/

 

[Vanadium 50]

Thanks - that's what I was looking for.

 

[Nik_2213]

I've not seen any reports from the field: Did it happen ??

 

[Vanadium 50]

Did it happen ??

Did the asteroid disappear? Did the star go out? I think not.

Maybe it has something to do with the fact that it's only been 10 working days plus a major holiday since then.

 

[mfb]

It happened. Videos of it aren't very spectacular, and data analysis will take months.

 

[DaveC426913]

It happened. Videos of it ...

Thanks. That's all I wanted.

It's pretty darned cool to see a cosmic event occurring in real time of an object 550ly away. (OK, technically the event is more like 30 light minutes away, but still). I would have loved to be able look up and see it.