Andrew Yee[_1_]
June 12th 08, 02:53 PM
ESA News
http://www.esa.int
10 June 2008
Detective astronomers unearth hidden celestial gem
ESA's orbiting X-ray observatory XMM-Newton has re-discovered an ignored
celestial gem. The object in question is one of the youngest and brightest
supernova remnants in the Milky Way, the corpse of a star that exploded
around 1000 years ago.
Its shape, age and chemical composition will allow astronomers to better
understand the violent ways in which stars end their lives.
Exploding stars seed the Universe with heavy chemical elements necessary to
build planets and create life. The expanding cloud of debris that each
explosion leaves behind, known as a supernova remnant (SNR), is a bright
source of X-rays and radio waves. Generally, the debris is thought to appear
as an expanding bubble or ring.
When astronomers took the first high-resolution radio images of a celestial
object known as 'G350.1-0.3' in the 1980s, they saw an irregular knot of
gases that did not seem to meet these expectations. So it was classified as
a probable background galaxy and was quietly forgotten.
Now Bryan Gaensler and Anant Tanna, both at the University of Sydney, have
used the X-ray capabilities of XMM-Newton with their colleagues to prove
that appearances can be deceptive. G350.1-0.3 is indeed the debris of an
exploded star despite its misshapen configuration.
In fact, it turns out to be one of the youngest and brightest supernova
remnants in the Milky Way.
To explain its shape, the team looked at radio surveys and discovered that
G350.1-0.3 had exploded next to a dense cloud of gas about 15 000
light-years from Earth. The cloud prevented the blast from expanding evenly
in all directions, resulting in an example of a rare kind of misshapen
supernova remnant.
G350.1-0.3 is incredibly small and young in astronomical terms, only eight
light years across and about 1000 years old. "Only a handful of such young
supernova remnants are known. So even having one more is important," says
Tanna. That is because young supernova remnants are highly luminous, with
the newly-formed chemical elements glowing brightly, making them easier to
study.
"We're seeing these heavy elements fresh out of the oven," says Gaensler.
Young supernova remnants exhibit the newly created elements and also contain
clues about the way the original star exploded. Such information is lost in
most supernova remnants because, as they expand and age, they lose their
initial characteristics. "After 20 000 years, all sorts of explosions look
more or less the same," says Gaensler.
Astronomers now recognise that stars explode in many different ways. Some
might be just big enough for an explosion to occur, others might be much
more massive. There are differences in the chemical composition of the
exploding stars and some may have a companion star in orbit around them.
Gaensler and Tanna hope that further investigations of G350.1-0.3 will yield
clues as to exactly what kind of star exploded. "It may turn out that many
of the youngest supernova remnants have these strange shapes," says Tanna,
"The hunt to find more is now on."
Despite the light from the supernova having reached Earth during the time of
William the Conqueror, Gaensler thinks humans would not have seen it. "The
X-ray data tell us that there's a lot of dust lying between it and Earth.
Even if you'd been looking straight at it when it exploded, it would've been
invisible to the naked eye," he says.
Thankfully, XMM-Newton's sensitivity and the detective work by Gaensler and
Tanna mean that this important celestial object will never again be
forgotten.
Notes for editors:
These findings will be published today in 'The (re-)discovery of G350.10.3:
A young, luminous supernova remnant and its neutron star' by B. Gaensler, A.
Tanna, P. Slane, C. Brogan, J. Gelfand, N. McClure-Griffiths, F. Camilo, C.
Ng and J. Miller in The Astrophysical Journal Letters.
For more information:
Bryan Gaensler, School of Physics, University of Sydney
Email: Bgaensler @ usyd.edu.au
Norbert Schartel, ESA XMM-Newton Project Scientist
Email: Norbert.Schartel @ esa.int
[NOTE: Images and weblinks supporting this release are available at
http://www.esa.int/esaCP/SEM1OPUG3HF_index_1.html ]
http://www.esa.int
10 June 2008
Detective astronomers unearth hidden celestial gem
ESA's orbiting X-ray observatory XMM-Newton has re-discovered an ignored
celestial gem. The object in question is one of the youngest and brightest
supernova remnants in the Milky Way, the corpse of a star that exploded
around 1000 years ago.
Its shape, age and chemical composition will allow astronomers to better
understand the violent ways in which stars end their lives.
Exploding stars seed the Universe with heavy chemical elements necessary to
build planets and create life. The expanding cloud of debris that each
explosion leaves behind, known as a supernova remnant (SNR), is a bright
source of X-rays and radio waves. Generally, the debris is thought to appear
as an expanding bubble or ring.
When astronomers took the first high-resolution radio images of a celestial
object known as 'G350.1-0.3' in the 1980s, they saw an irregular knot of
gases that did not seem to meet these expectations. So it was classified as
a probable background galaxy and was quietly forgotten.
Now Bryan Gaensler and Anant Tanna, both at the University of Sydney, have
used the X-ray capabilities of XMM-Newton with their colleagues to prove
that appearances can be deceptive. G350.1-0.3 is indeed the debris of an
exploded star despite its misshapen configuration.
In fact, it turns out to be one of the youngest and brightest supernova
remnants in the Milky Way.
To explain its shape, the team looked at radio surveys and discovered that
G350.1-0.3 had exploded next to a dense cloud of gas about 15 000
light-years from Earth. The cloud prevented the blast from expanding evenly
in all directions, resulting in an example of a rare kind of misshapen
supernova remnant.
G350.1-0.3 is incredibly small and young in astronomical terms, only eight
light years across and about 1000 years old. "Only a handful of such young
supernova remnants are known. So even having one more is important," says
Tanna. That is because young supernova remnants are highly luminous, with
the newly-formed chemical elements glowing brightly, making them easier to
study.
"We're seeing these heavy elements fresh out of the oven," says Gaensler.
Young supernova remnants exhibit the newly created elements and also contain
clues about the way the original star exploded. Such information is lost in
most supernova remnants because, as they expand and age, they lose their
initial characteristics. "After 20 000 years, all sorts of explosions look
more or less the same," says Gaensler.
Astronomers now recognise that stars explode in many different ways. Some
might be just big enough for an explosion to occur, others might be much
more massive. There are differences in the chemical composition of the
exploding stars and some may have a companion star in orbit around them.
Gaensler and Tanna hope that further investigations of G350.1-0.3 will yield
clues as to exactly what kind of star exploded. "It may turn out that many
of the youngest supernova remnants have these strange shapes," says Tanna,
"The hunt to find more is now on."
Despite the light from the supernova having reached Earth during the time of
William the Conqueror, Gaensler thinks humans would not have seen it. "The
X-ray data tell us that there's a lot of dust lying between it and Earth.
Even if you'd been looking straight at it when it exploded, it would've been
invisible to the naked eye," he says.
Thankfully, XMM-Newton's sensitivity and the detective work by Gaensler and
Tanna mean that this important celestial object will never again be
forgotten.
Notes for editors:
These findings will be published today in 'The (re-)discovery of G350.10.3:
A young, luminous supernova remnant and its neutron star' by B. Gaensler, A.
Tanna, P. Slane, C. Brogan, J. Gelfand, N. McClure-Griffiths, F. Camilo, C.
Ng and J. Miller in The Astrophysical Journal Letters.
For more information:
Bryan Gaensler, School of Physics, University of Sydney
Email: Bgaensler @ usyd.edu.au
Norbert Schartel, ESA XMM-Newton Project Scientist
Email: Norbert.Schartel @ esa.int
[NOTE: Images and weblinks supporting this release are available at
http://www.esa.int/esaCP/SEM1OPUG3HF_index_1.html ]