Famous 400-year old Supernova revealed to be double-white dwarf explosion

400-Year-Old Star Explosion Mystery Finally Solved | Supernovas & White
Dwarf Stars | Star Mysteries & 219th American Astronomical Society
Meeting | Space.com
http://www.space.com/14202-supernova...ed-aas219.html

"Call it a cosmic scene investigation. A team of astronomer sleuths has
identified the trigger for a powerful supernova that exploded four
centuries ago, finding it to be the collision of two white dwarf stars.

The discovery settles decades of questions over the origin of so-called
Type 1a supernovas, researchers said.

Astronomers have long suspected that two stars were responsible for the
explosion, with one being a white dwarf — a compact, dying star. But
scientists weren't sure if both culprits were white dwarf stars that
crashed, or consisted of one white dwarf that siphoned off material from
a regular companion star. Both scenarios could cause the supernova."

Dear Yousuf Khan:

On Jan 12, 7:45*am, Yousuf Khan wrote:
400-Year-Old Star Explosion Mystery Finally Solved |
Supernovas & White Dwarf Stars | Star Mysteries &
219th American Astronomical Society Meeting |
Space.com
snip link now broken by Google.Groups

"Call it a cosmic scene investigation. *A team of
astronomer sleuths has identified the trigger for a
powerful supernova that exploded four centuries
ago, finding it to be the collision of two white dwarf
stars.

The discovery settles decades of questions over
the origin of so-called Type 1a supernovas,
researchers said.

Astronomers have long suspected that two stars
were responsible for the explosion, with one being
a white dwarf — a compact, dying star. But
scientists weren't sure if both culprits were white
dwarf stars that crashed, or consisted of one white
dwarf that siphoned off material from a regular
companion star. Both scenarios could cause the
supernova."

23 light years across, after ~400 years... less than 0.03c from
center. All that raw power, and that is all the faster the "blast
wave" moves...

David A. Smith

dlzc wrote:
Dear Yousuf Khan:

On Jan 12, 7:45 am, Yousuf Khan wrote:
400-Year-Old Star Explosion Mystery Finally Solved |
Supernovas & White Dwarf Stars | Star Mysteries &
219th American Astronomical Society Meeting |
Space.com
snip link now broken by Google.Groups

"Call it a cosmic scene investigation. A team of
astronomer sleuths has identified the trigger for a
powerful supernova that exploded four centuries
ago, finding it to be the collision of two white dwarf
stars.

The discovery settles decades of questions over
the origin of so-called Type 1a supernovas,
researchers said.

Astronomers have long suspected that two stars
were responsible for the explosion, with one being
a white dwarf — a compact, dying star. But
scientists weren't sure if both culprits were white
dwarf stars that crashed, or consisted of one white
dwarf that siphoned off material from a regular
companion star. Both scenarios could cause the
supernova."

23 light years across, after ~400 years... less than 0.03c from
center. All that raw power, and that is all the faster the "blast
wave" moves...

David A. Smith

If you think a speed of 9000 km/sec is "slow", that's your problem, isn't
it? Sounds pretty fast to me, and quite typical of supernova envelope
expansion speeds.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

Dear Mike Dworetsky:

On Jan 12, 3:21*pm, "Mike Dworetsky"
wrote:
dlzc wrote:
Dear Yousuf Khan:

On Jan 12, 7:45 am, Yousuf Khan wrote:
400-Year-Old Star Explosion Mystery Finally Solved |
Supernovas & White Dwarf Stars | Star Mysteries &
219th American Astronomical Society Meeting |
Space.com
snip link now broken by Google.Groups

"Call it a cosmic scene investigation. A team of
astronomer sleuths has identified the trigger for a
powerful supernova that exploded four centuries
ago, finding it to be the collision of two white dwarf
stars.

The discovery settles decades of questions over
the origin of so-called Type 1a supernovas,
researchers said.

Astronomers have long suspected that two stars
were responsible for the explosion, with one being
a white dwarf — a compact, dying star. But
scientists weren't sure if both culprits were white
dwarf stars that crashed, or consisted of one white
dwarf that siphoned off material from a regular
companion star. Both scenarios could cause the
supernova."

23 light years across, after ~400 years... less than
0.03c from center. *All that raw power, and that is all
the faster the "blast wave" moves...

If you think a speed of 9000 km/sec is "slow", that's your
problem, isn't it?

Not really.

*Sounds pretty fast to me, and quite typical of supernova
envelope expansion speeds.

People whine and complain about Relativity, like it was keeping our
butts on this planet. Here we have a relative whiff of gas, propelled
by a supernova. It would take about 143 years to get to the nearest
star had it started here, and relativistic effects wouldn't be all
that much.

I'm just trying to show some perspective here, not trying to say how
puny supernovas are.

Good to know the speeds are typical. Thanks.

Is the "glow" recombination of (primarily) outbound material, or
interaction of outbound material with interstellar medium... do you
know?

David A. Smith

dlzc wrote:
Dear Mike Dworetsky:

On Jan 12, 3:21 pm, "Mike Dworetsky"
wrote:
dlzc wrote:
Dear Yousuf Khan:

On Jan 12, 7:45 am, Yousuf Khan wrote:
400-Year-Old Star Explosion Mystery Finally Solved |
Supernovas & White Dwarf Stars | Star Mysteries &
219th American Astronomical Society Meeting |
Space.com
snip link now broken by Google.Groups

"Call it a cosmic scene investigation. A team of
astronomer sleuths has identified the trigger for a
powerful supernova that exploded four centuries
ago, finding it to be the collision of two white dwarf
stars.

The discovery settles decades of questions over
the origin of so-called Type 1a supernovas,
researchers said.

Astronomers have long suspected that two stars
were responsible for the explosion, with one being
a white dwarf — a compact, dying star. But
scientists weren't sure if both culprits were white
dwarf stars that crashed, or consisted of one white
dwarf that siphoned off material from a regular
companion star. Both scenarios could cause the
supernova."

23 light years across, after ~400 years... less than
0.03c from center. All that raw power, and that is all
the faster the "blast wave" moves...

If you think a speed of 9000 km/sec is "slow", that's your
problem, isn't it?

Not really.

Sounds pretty fast to me, and quite typical of supernova
envelope expansion speeds.

People whine and complain about Relativity, like it was keeping our
butts on this planet. Here we have a relative whiff of gas, propelled
by a supernova. It would take about 143 years to get to the nearest
star had it started here, and relativistic effects wouldn't be all
that much.

I'm just trying to show some perspective here, not trying to say how
puny supernovas are.

Good to know the speeds are typical. Thanks.

Is the "glow" recombination of (primarily) outbound material, or
interaction of outbound material with interstellar medium... do you
know?

Caveat: I didn't read this particular paper, but in general, as I recall,

The initial emission of light over a few weeks or months is governed by
energy from the decay of radioactive nuclei created during the explosion,
but after 400 years, it is mainly from the collisions of the expanding
envelope with the interstellar medium gases. The expanding envelope is
faster than the speed of sound in the tenuous gas, so it's a a shock wave.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

On 1/12/2012 11:21 AM, dlzc wrote:
23 light years across, after ~400 years... less than 0.03c from
center. All that raw power, and that is all the faster the "blast
wave" moves...

Yeah, I was thinking the same thing. One of the biggest blasts in the
universe, and that's the only catapult you get out of it.

Yousuf Khan