Vampire Star Is a Ticking Time Bomb

[Nyrath]

http://www.space.com/scienceastronom...time-bomb.html

The VLT data also suggest that V445 Puppis could one day explode as a Type 1a supernova.

[Nyrath]

this is cool too
http://antwrp.gsfc.nasa.gov/apod/ap091117.html

[Ian Mackinder]

Very cool.

[Nyrath]

Better images:
http://blogs.discovermagazine.com/ba...ova-time-bomb/

[Cancer]

At 7600 parsecs away, though, V445 Pup is NOT a threat to us, even if it does go boom one day.

[Cancer]

The art piece is cool, but I have a laundry list of things that are scientifically wrong about it. I have, however, already been accused on these boards of having no poetry in my soul.

[L. Marcus]

It was a compliment already! Now spill.

[Nyrath]

no, of course it is too far away to do any damage. To Earth.

But the same is not true for your hapless stable of players, offered a cool million credits by their patron if they place the Uncrackable Walnut of Infinity close enough to V445 Puppis. And he is mostly sure he has the correct figure for when it will explode.

[L. Marcus]

... A year, give or take.

[Cancer]

Unlike Type II's, where the time bomb is in the core and (barring a good way of seeing neutrinos) you don't get good warning when the thing's about to blow, there is hope of seeing impending doom with a Type Ia. The smaller the white dwarf gets, the closer you are to going bang.

[L. Marcus]

Any idea how good a heads-up the crew would get?

[Kristopher]

Unlike Type II's, where the time bomb is in the core and (barring a good way of seeing neutrinos) you don't get good warning when the thing's about to blow, there is hope of seeing impending doom with a Type Ia. The smaller the white dwarf gets, the closer you are to going bang.

Smaller?

As in less volume, right?

[L. Marcus]

Yup. The matter falling onto the star compresses.

[Cancer]

Yeah, the radius for a star supported by degenerate electron pressure (that is, a white dwarf) is a decreasing function of mass. The Chandrasekhar limit on the mass is where the radius falls to zero. The radius doesn't actually go to zero; other physics takes over as the electrons are squeezed into the nuclei, the protons are all converted to neutrons, vast numbers of neutrinos are formed and liberated, and in the absence of electrostatic repulsion the material goes into free fall. This liberates about 10^53 ergs of energy, of which 99% escapes as neutrinos. 10^51 ergs goes into the blast and the visible outburst ... still quite enough to toast the local neighborhood.

[L. Marcus]

Mmmm. Marshmallow planets.