[Vision2020] Supernova

[Jay Borden]

Does anyone have plans to wander outside after twilight with their
binoculars/telescopes this evening?  The supernova is located by the
"panhandle" of the big dipper.

 

Jay

 

 

>From the SFGate:

 

A dying star that exploded 21 million years ago in a cataclysmic burst
of energy called a supernova has sent its light streaming across the
cosmos, leaving a pinpoint of light in the sky that Bay Area residents
with a good pair of binoculars should be able to see over the next two
nights.

The supernova, brighter than all the stars in the universe combined,
blazed from a galaxy near the constellation Big Dipper, according Peter
Nugent, an astronomer and senior scientist at the Lawrence Berkeley
National Laboratory who detected its light last week.

Despite its explosive brilliance, the light is dim at this distance. Its
faint light will reach its peak tonight and Friday night, and should be
visible in the clear night sky through a quality pair of binoculars or
with amateur telescopes of 3 inches or larger, Nugent said.

He picked up the supernova soon after the explosion became visible on
Aug. 23 in an image sent from an automated telescope at the famed
Palomar Observatory near San Diego. Astronomers haven't seen a supernova
so close to Earth in 25 years, he said - nor one as bright in more than
40 years.

While the explosion was immense, it involved a star of only modest
dimensions - a white dwarf only 1.4 times the mass of our sun, Nugent
said.

Supernovas are common, but most are more than a billion light-years away
and are too faint to be visible except through the most powerful
telescopes. So the opportunity to observe one only 21 million
light-years away has astronomers aiming their telescopes at the blast
from observatories around the world.

The Hubble Space Telescope has also been assigned to begin studying the
physics and chemistry of the explosion, NASA officials said.

This supernova is classed as Type 1a, and is catalogued under the name
PTF11kly. The exploding star was one member of a stellar pair, known as
a binary system, that had already burned away its hydrogen and helium in
thermonuclear explosions, leaving only its carbon and oxygen to fuel the
final outburst, Nugent said.

Because the light intensity of supernovas is well-known, astronomers use
them as "standard candles" to calculate the distances of far-off
galaxies, and thus to measure the rate at which the entire universe is
expanding under the mysterious influence of what is called dark energy,
Nugent explained.

Alex Filippenko, leader of a team of supernova observers at the UC Lick
Observatory, said this newest one will prove valuable in helping
astronomers to refine their distance calculations for those "standard
candles."

It should also shed new light on the exploding star's companion,
Filippenko said. For example, astronomers might be able to determine
whether the binary pair were both originally white dwarf stars, and
whether the star that exploded might have been "stealing matter from its
companion" as it built up toward its final blast, or - perhaps - whether
both stars merged to explode in a single blast.

Every explosion of a supernova sends out bursts of all the elements that
make up every bit of matter in the universe. "All the calcium in our
bones, all the iron in our blood, all the chemicals in our bodies, came
originally from supernovas that exploded even before the Earth was
formed," Nugent said.



Read more:
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2011/09/07/BABK1L0P5I.D
TL#ixzz1XO2Df85J
<http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2011/09/07/BABK1L0P5I.
DTL#ixzz1XO2Df85J> 

 

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