Betelgeuse will go supernova？？

[magnetar]

A recent study indicates that Betelgeuse has decreased in size by 15% since 1993.

http://esciencenews.com/articles/2009/06/09/red.giant.star.betelgeuse.mysteriously.shrinking

 

[Astronuc]

Betelgeuse is being monitored.

. . . .
Townes and his colleague, Edward Wishnow, a research physicist at UC Berkeley's Space Sciences Laboratory, will discuss their findings at a 12:40 p.m. PDT press conference on Tuesday, June 9, during the Pasadena meeting of the American Astronomical Society (AAS). The results were published June 1 in The Astrophysical Journal Letters.

Despite Betelgeuse's diminished size, Wishnow pointed out that its visible brightness, or magnitude, which is monitored regularly by members of the American Association of Variable Star Observers, has shown no significant dimming over the past 15 years.

The ISI has been focusing on Betelgeuse for more than 15 years in an attempt to learn more about these giant massive stars and to discern features on the star's surface, Wishnow said. He speculated that the measurements may be affected by giant convection cells on the star's surface that are like convection granules on the sun, but so large that they bulge out of the surface. Townes and former graduate student Ken Tatebe observed a bright spot on the surface of Betelgeuse in recent years, although at the moment, the star appears spherically symmetrical.
. . . .

Betelgeuse, Red Supergiant In Constellation Orion, Has Shrunk By 15 Percent In 15 Years
http://www.sciencedaily.com/releases/2009/06/090609220555.htm

Red giant star Betelgeuse mysteriously shrinking (UC Berkeley News)
http://berkeley.edu/news/media/releases/2009/06/09_betelim.shtml

Where do supernovae come from?

Two Dying Red Supergiant Stars Produced Supernovae
http://www.sciencedaily.com/releases/2009/03/090319142405.htm

AAVSO really needs to update this - http://www.aavso.org/vstar/vsots/1200.shtml

 

[Chronos]

Betelguese will someday go supernova, but, probably not today. The oscillations observed over the last century do not appear unusual for such a star. It will do should do this oscillation thing many times before it gives up the ghost. Best guess is it has at least a hundred million years left before the big event.

 

[magnetar]

Unveiling the true face of Betelgeuse
DR EMILY BALDWIN
ASTRONOMY NOW
Posted: July 29, 2009
http://www.astronomynow.com/news/n0907/29betel/

 

[Unix Ronin]

Best guess is it has at least a hundred million years left before the big event.

My understanding is it is extremely unlikely Betengeuse will last that long. It's a gigantic star (the ninth largest known), burning through its fuel at a prodigious rate, and is believed to be significantly less than ten million years old. At this point in its stellar evolution, its chances of lasting another million years before it goes supernova are considered slim, and a hundred million years is almost certainly out of the question.

 

[brother time]

My understanding is it is extremely unlikely Betelgeuse will last that long. It's a gigantic star (the ninth largest known), burning through its fuel at a prodigious rate, and is believed to be significantly less than ten million years old. At this point in its stellar evolution, its chances of lasting another million years before it goes supernova are considered slim, and a hundred million years is almost certainly out of the question.

I agree with this information however, many people think the supernova will occur in the next 1000 years. the star is about 640 light years away and is as Unix said, very old. It would be cool to see but we are unlikely to see it.
cheers, BT

 

[Orion1]

Type II-P supernova

Betelgeuse is a semiregular variable star located approximately 640 light-years from the Earth. Semiregular variable stars are giants or supergiants of intermediate and late spectral type showing considerable periodicity in their light changes, accompanied or sometimes interrupted by various irregularities. Periods lie in the range from 20 to more than 2000 days, while the shapes of the light curves may be rather different and variable with each cycle. The amplitudes may be from several hundredths to several magnitudes (usually 1-2 magnitudes in the V filter).

The future fate of this star depends on its mass; as it probably contains more than 15 solar masses, it will continue to burn and fuse elements until the core is iron, at which point Betelgeuse will explode as a type II supernova. During this event the core will collapse, leaving behind a neutron star remnant some 20 km in diameter. However, if Betelgeuse is at the lighter end of estimated mass, it may instead contract to become a white dwarf.

Considering its size and age of 8.5 million years, old for its size class, Betelgeuse may explode within the next thousand years. At the current distance of Betelgeuse from the Earth, such a supernova explosion it would be the brightest recorded; outshining the Moon in the night sky and becoming easily visible in broad daylight.

The supernova would brighten to apparent magnitude –12 over a two week period, then remain at that intensity for two or three months before rapidly dimming. The year following the explosion, radioactive decay of cobalt to iron will dominate emission from the supernova remnant, and the resulting gamma rays will be blocked by the expanding envelope of hydrogen. If the neutron star remnant became a pulsar, then it might produce gamma rays for thousands of years.

Main sequence solar lifetime:
$$t_{L} = 11 \cdot 10^{9} \; \text{y}$$

Red supergiant star stellar lifetime:
$$\boxed{\tau_{rs} = t_{L} \left(\frac{m_{\odot}}{m_s} \right)^{2.47908}}$$

$$m_{\odot}$$ - solar mass
$$m_s$$ - stellar mass

Betelgeuse mass:
$$m_s = 18 \; m_{\odot}$$

Stellar lifetime for red supergiant star with Betelgeuse mass:
$$\boxed{\tau_{rs} = 8.501 \cdot 10^6 \; \text{y}}$$

Betelgeuse may explode in a type II supernova within the next thousand years.

Reference:
http://en.wikipedia.org/wiki/Main_sequence#Lifetime"
http://en.wikipedia.org/wiki/Betelgeuse#Fate"
http://en.wikipedia.org/wiki/Semiregular_variable_star"

 

[Borek]

https://www.physicsforums.com/showthread.php?t=405304

 

[Borek]

is believed to be significantly less than ten million years old

the star is (...) as Unix said, very old

Sorry, 10 million years in stellar terms is a newborn. 10 billion years would be a lot.

 

[brother time]

It's a supergiant. they don't live very long.
cheers, BT

 

[nismaratwork]

It's a supergiant. they don't live very long.
cheers, BT

There is a lot about this class of star, and Betelgeuse in particular that is somewhat mysterious, including mass-loss. I think it's a bit hopeful to think it will explode within a thousand years, but your point with Borek is still valid; these stars do not live for 10 million years, never mind a billion. I think the best estimate of age is 8.5 million years, and it would be impressive if it saw 9 million.