Starship Asterisk*

How far away would a star have to be to NOT affect earth when it went "nova"? Thanks.

You mean "supernova", don't you? A "nova" is just a sudden brightening of a star, usually a white dwarf or a neutron star in a binary system, not a violent event like a supernova. As for the safe distance, I don't remember exactly, buty I think the supernova would have to be more than 200 light years to NOT affect us.

Hello all


Supa Nova has affected the earth some 200 million years ago or so when our solar system went through a nebulae.

Other than that some supa nova have given night shows in the past.

Here is a Space.com article on this particular subject, albeit a little old (December 2002). Current theory seems to suggest that the Earth would be safe from any supernova event occuring farther away than about 10 parsecs, or roughly 30 light years. At this point in time, there are no stars within about twice this distance that will go supernova for at least several million years, so it's not something we're too likely to need to worry about.

Now a beamed event, something like a hypernova or gamma-ray burst... that I'm not sure about. They tend to have a much longer reach. Estimates I've read hint at a dangerous range of a few thousand light years... if Earth happened to fall along the beam of the explosion.

Doesn't it belong to this thread?

Thank you all. I DO appreciate the info.

Hello Qev

I could not open the link above. But I ajusted the url to this

http://www.space.com/scienceastronomy/s ... 21216.html

Just incase someone wants to open it. It was refered to by Qev

quotes:
"Researchers have suggested that one or more mass extinctions during the past few hundred million years might have been triggered by supernovae, and that it might happen again."

"Separate research has shown that exposure to high-energy particles from space, over time, could cause genetic mutations."


I think planet earth is a lucky planet when all is said and done.
Sweet dreams



"Another worry are so-called hypernovae, which are related to mysterious gamma-ray bursts in deep space. Astronomers believe these are similar to supernovae but that a beam of concentrated energy, emanating along the star's axis of rotation, happens to be pointed at Earth."

"Though the new study did not look into the hypernovae hazard, Gehrels said it's likely for one aimed at Earth to occur once every couple of hundred million years somewhere in our galaxy, most of the time at a very large distance from our planet, however"

"Given that there are some 100 billion galaxies in that space, this rate translates into about one gamma ray burst from inside our galaxy beamed toward Earth every 200 million years. Because the energy is so concentrated compared to a normal supernova, hypernovae could potentially be harmful to life on Earth at much greater distances than supernovae"

Since an answer to original question has been accepted, I lock this in favour of this thread.