May 16th 11, 11:55 PM
posted to sci.astro.amateur,sci.astro,sci.physics
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Some colliding white dwarfs can reignite fusion rather than gosupernova
On 5/16/11 2:53 PM, Brad Guth 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.
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...
They'll also have to encounter a substantial molecular cloud of
hydrogen and helium. Is there one of those nearby?
More likely it'll just soft-nova and become another white dwarf,
because there's not enough combined mass or impact velocity to
supernova.
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Brad Guth, Brad_Guth, Brad.Guth, BradGuth, BG / “Guth Usenet”
Carbon/Oxygen core makes up at least 99% of the White Dwarf's mass.
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