Join the Unexplained Mysteries community today! It's free and setting up an account only takes a moment.
- Sign In or Create Account -
Sign in to follow this  
Followers 0
Roj47

If a supernova occurred....

11 posts in this topic

Possibly getting myself confused here, but if a star went supernova, and was located a 1/2 light year from Earth. How would our sky look and would Earth have to begin a countdown to destruction?

Share this post


Link to post
Share on other sites

I don't think this thread is in the right place, I thought only news where posted in the Space News forum, and discussion in the Space and Astronomy forum............

Anyways! Supernovas have been known to make nabulas a few light years across so....... the solar system would be destroyed.

Share this post


Link to post
Share on other sites

Im fairly sure if there was a start big enough to go supernova within 1/2 a light year, we'd know about it! Though if that star was Alpha Centauri for example, I think its close enough to give us really bad sunburn at the very least.

Thats if we managed to avoid an awful lot of solar radiation.

Share this post


Link to post
Share on other sites
I don't think this thread is in the right place, I thought only news where posted in the Space News forum, and discussion in the Space and Astronomy forum............

Anyways! Supernovas have been known to make nabulas a few light years across so....... the solar system would be destroyed.

Agreed its the wrong place :(

Posted the thread having read Waspie_Dwarf's thread.... Any chance of moving?

More wondering of the event rather than the distance..... Would it be possible to have a situation where there is a nebular 5+ times the size of the moon in the sky and Earth knowing that in 40 years time the energy would hit.

Share this post


Link to post
Share on other sites
Any chance of moving?

Every chance indeed :tu:

Share this post


Link to post
Share on other sites

so which is it? the solar system destroyed or we get a little sunburned?

Share this post


Link to post
Share on other sites
Im fairly sure if there was a start big enough to go supernova within 1/2 a light year, we'd know about it! Though if that star was Alpha Centauri for example, I think its close enough to give us really bad sunburn at the very least.

Thats if we managed to avoid an awful lot of solar radiation.

Alpha Centauri won't become a supernova. You need a bit more mass to accomplish that task. Of course, there aren't any stars 1/2 LY distant, and we'd certainly know about a massive sun that close by (and could probably see it as the most prominent star in our skies at night) so it's not looking like we have to worry about it.

Share this post


Link to post
Share on other sites

Posted (edited)

That's a good resource, it covers all sorts of information about magnitudes, radiation fluxes, etc. The only question it doesn't answer is

Would it be possible to have a situation where there is a nebular 5+ times the size of the moon in the sky

The moon covers 1/2 degree in the sky. For something 1.5 light years away to have an angular size of 5 times that (i.e. 2.5 degrees), that would mean it spans 0.065 light years--that is, a distance about 24 light days across. So if this supernova were spewing material at the speed of light, it would take about 12 days to reach a size big enough to cover 5 moons in our sky. In reality, though, the velocity at which matter expands in a supernova is closer to 1/166 the speed of light, so it would take closer to five and a half years to look that big in our sky, presuming it wasn't diffuse enough by that point that the grandeur of the sight was dampened.

Edited by Startraveler

Share this post


Link to post
Share on other sites
so which is it? the solar system destroyed or we get a little sunburned?

Please read this. ( Bold parts a most important)

A supernova is a stellar explosion that creates an extremely luminous object that is initially made of plasma—an ionized form of matter. A supernova may briefly outshine its entire host galaxy before fading from view over several weeks or months. During this brief period of time, the supernova radiates as much energy as the Sun would emit over about 10 billion years. The explosion expels much or all of a star's material at a velocity of up to a tenth the speed of light, driving a shock wave into the surrounding interstellar gas. This shock wave sweeps up an expanding shell of gas and dust called a supernova remnant. There are several types of supernovae and at least two possible routes to their formation. A massive star may cease to generate energy from the nuclear fusion of atoms in its core, and collapse under the force of its own gravity to form a neutron star or black hole. Alternatively, a white dwarf star may accumulate material from a companion star (either through accretion or a collision) until it nears the Chandrasekhar limit of roughly 1.44 times the mass of the Sun, at which point it undergoes runaway nuclear fusion in its interior, completely disrupting the star. On average, supernovae occur about once every 50 years in a galaxy the size of the Milky Way and play a significant role in enriching the interstellar medium with heavy elements. Furthermore, the expanding shock waves from supernova explosions can trigger the formation of new stars. (more...)

Recently featured: Super Nintendo Entertainment System – Robert Baden-Powell – École Polytechnique massacre

So... many things can happen. I hope that answered you question.

Source

Share this post


Link to post
Share on other sites
The moon covers 1/2 degree in the sky. For something 1.5 light years away to have an angular size of 5 times that (i.e. 2.5 degrees), that would mean it spans 0.065 light years--that is, a distance about 24 light days across. So if this supernova were spewing material at the speed of light, it would take about 12 days to reach a size big enough to cover 5 moons in our sky. In reality, though, the velocity at which matter expands in a supernova is closer to 1/166 the speed of light, so it would take closer to five and a half years to look that big in our sky, presuming it wasn't diffuse enough by that point that the grandeur of the sight was dampened.

So... many things can happen. I hope that answered you question.

Many thanks guys for helping me learn more about the subject. I only wish I had the time (and ability) to read and digest more.

:tu:

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0

  • Recently Browsing   0 members

    No registered users viewing this page.