On 5/16/11 6:21 PM, Eric Gisse wrote:
On May 15, 10:36 pm, Yousuf wrote:
Colliding white dwarfs give each other a new lease on life
"Astronomers recently discovered the rather memorably named SDSS
J010657.39–100003.3, which is a binary star system composed of two white
dwarfs, one of which is 17% the Sun's mass, while the other is about
43%. The two orbit each other at a distance of just 140,000 miles, which
is even closer than the distance between the Earth and the Moon. The two
rotate each other at about a million miles per hour.

A factor of 4 or so closer in separation compared to the Hulse-Taylor
pulsar system, but with significantly less mass. And no pulsar for
timing.

This system will decay via gravitational radiation too. Wonder how
long it'd take.


When white dwarfs collide, one of two things can happen: if the combined
masses is greater than 140% of the Sun, the collision creates a
supernova. But in this case, the white dwarfs will actually reignite
nuclear fusion, creating a brand new star just like our Sun that will,
after another few billion years of renewed life, cool down into yet
another white dwarf."http://ca.io9.com/5801997/colliding-white-dwarfs-give-each-other-a-ne...

I wonder what type of supernova that would be. Not a 1a - that's a
helium flash from accretion, and not a II which is a core
collapse...probably be rather noisy, perhaps a candidate the fast
variety of GRB's?


If exceeding the Chandrasekhar limit of 1.44 solar masses creates
a Type IA supernova, I'm betting that two colliding white dwarfs
will do similar.