What will happen when Betelgeuse goes supernova?

[llivinglarge]

Also, how much longer until that happens?<br /><br />If it went supernova tomorrow, would it really take 450 years for us to observe it?

 

[harmonicaman]

Betelgeuse overview.<br /><br />HST APOD of Alpha Orionis<br /><br /><i>"Also, how much longer until that happens?"</i><br /><br />Hard to say; since it's 450 LYs away, its difficult to get a precise measurement of what's going on. We have the same problem predicting volcanoes here on Earth -- we know they are going to occur but we can't predict the exact second of eruption.<br /><br /><i>"If it went supernova tomorrow, would it really take 450 years for us to observe it?"</i><br /><br />Yes, the light we are seeing from Betelgeuse is approximately 450 years old. Even the light from our own Sun is from the past; it takes eight minutes for the light of the Sun to reach us. <br /><br />We see stars on the other side of the Milky Way as they were 100,000 years ago because our galaxy is so large and the stars are so distant that it takes their light 100,000 years to reach us! <br /><br />Another supernova waiting to happen; Eta Carinae.

 

[alokmohan]

Agreed on both counts

 

[bbrock]

The supernova part is a guess. We know it's pulsating and well off of the main sequence. Some time in the next two million years, perhaps. <br /><br />Clear Skies<br />Bill

 

[qso1]

It would probably be as bright or maybe brighter than Sirius in our night sky and may even be visible in the early morning or late evening. I recall reading somewhere that the radiation would be a hazard to astronauts but our atmosphere would shield us here on Earth. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[alokmohan]

450 ly is not much distant.We may face hazards .It will be good sight seeing if we survive of course.

 

[qso1]

This is true and nobody knows for sure what exactly will happen if and when it does. If it happens within our lifetimes, it will be an impressive sight. Especially if visible during daylight hours. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[alokmohan]

Will it be bigger than 1987 supernova,though too early to say?

 

[vogon13]

SN1987A was 160000+ ly away.<br /><br />Bete is less than 1% of the distance.<br /><br />Could be pretty freakin' dramatic.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[qso1]

If it goes full blast or even close to full, it will definetely outshine SN1987A as pointed out by vogon13. I think it will be dramatic but not overly so because it is still relatively far away. I could be wrong of course because nobody really knows.<br /><br />One point of reference I use is the Crab nebula which was recorded as a nova in 1054 by Chinese astronomers. It was recorded as being visible in daylight for nearly a month and brighter than Venus. It was brighter at night than normal for around 2 years and seing how it occured roughly 7,000 years ago (The nebula is 6,000+ Ly distant), that would be over ten times Betels distance. I do not know if any details were recorded on just how much of a daytime event the Crab nova was. Was it just a pinpoint of light you had to struggle to see? Was it bright enough to cast shadows? I do not know. I also try to imagine what would happen if Sirius were to go supernova and that would be dramatic at its 8.7 Ly distance. Probably cast easy to see shadows, the expanding star atmosphere may even make it visible as a pinhead sized disc held at arms length. The radiation however, would probably be enough to kill surface lifeforms on planets within 20 Ly of the event.<br /><br />Then theres Eta Carinae at roughly 7,500 Ly away. This star had a brightening event in 1830 and again in 2001 which suggested to me that stars go nova in stages. Eta Car may be in a kind of pre nova stage. Some astronomers hypothesize Eta Car as being a potential hypernova and though its nearly a thousand times as distant as Sirius, it could put on quite the show although you'd have to be in the southern hemisphere to see it. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>