Andrew Yee[_1_]
April 2nd 08, 04:47 AM
ESA News
http://www.esa.int
1 April 2008
Exploding star in nearby galaxy
The latest image from the NASA/ESA Hubble Space Telescope reveals a sharp
view of the spiral galaxy NGC 2397. It shows a rare Hubble view of the early
stages of supernova SN 2006bc, discovered in March 2006.
NGC 2397 is a classic spiral galaxy with long, prominent dust lanes along
the edges of its arms, seen as dark patches and streaks silhouetted against
the starlight. Hubble's exquisite resolution allows the study of individual
stars in nearby galaxies.
Located nearly 60 million light-years away from Earth, NGC 2397 is typical
of most spirals, with mostly older, yellow and red stars in its central
portion, while star formation continues in the outer, bluer spiral arms. The
brightest of these young, blue stars can be seen individually in this
high-resolution view from Hubble's Advanced Camera for Surveys (ACS).
One atypical feature of this Hubble image is the view of supernova SN 2006bc
taken when its brightness was on the decrease. Astronomers at Queen's
University Belfast in Northern Ireland, led by Professor of Astronomy
Stephen J. Smartt, requested the image as part of a long project studying
massive exploding stars -- supernovae. Exactly which types of stars will
explode and the lowest mass of star that can produce a supernova are not
known.
When a supernova is discovered in a nearby galaxy, the group begins a
painstaking search of earlier Hubble images of the same galaxy to locate the
star that exploded later; often one of hundreds of millions of stars in the
galaxy. This is a little like sifting through days of CCTV footage to find
one frame showing a suspect.
If the astronomers find a star at the location of the later explosion, they
may work out the mass and type of star from its brightness and colour. Only
six such stars have been identified before they exploded and Smartt's team
have discovered the nature of five of them.
In their latest work on Hubble images, to be presented at the UK National
Astronomy Meeting 2008 in Belfast, the team reveals the results of their
ten-year search for these elusive supernova precursor stars. It seems that
stars with masses as low as seven times the mass of the Sun can explode as
supernovae. The team have not found any very massive stars that exploded,
suggesting that the most massive stars may collapse to form black holes
either without producing a supernova or by producing one that is too faint
to observe. This intriguing possibility will be discussed at the meeting.
A public lecture at Queen's University Belfast showing how the Hubble Space
Telescope has built a bridge between science and art will coincide with a
presentation of the latest scientific study of Hubble galaxy images by
astronomers at the university. The images were obtained on 14 October 2006
with Hubble's Advanced Camera for Surveys (ACS) with three different colour
filters (blue, green and near-infrared).
Notes for editors:
The Hubble Space Telescope is a project of international cooperation between
NASA and ESA.
The Royal Astronomical Society National Astronomy Meeting (NAM) 2008 will
take place at Queen's University Belfast from 31 March to 4 April.
For more information:
Lars Lindberg Christensen, Hubble/ESA, Garching, Germany
E-mail: Lars @ eso.org
Prof. Stephen Smartt, Queen's University Belfast
E-mail: S.Smartt @ qub.ac.uk
[NOTE: Images and weblinks supporting this release are available at
http://www.esa.int/esaSC/SEMSPG5QGEF_index_1.html ]
http://www.esa.int
1 April 2008
Exploding star in nearby galaxy
The latest image from the NASA/ESA Hubble Space Telescope reveals a sharp
view of the spiral galaxy NGC 2397. It shows a rare Hubble view of the early
stages of supernova SN 2006bc, discovered in March 2006.
NGC 2397 is a classic spiral galaxy with long, prominent dust lanes along
the edges of its arms, seen as dark patches and streaks silhouetted against
the starlight. Hubble's exquisite resolution allows the study of individual
stars in nearby galaxies.
Located nearly 60 million light-years away from Earth, NGC 2397 is typical
of most spirals, with mostly older, yellow and red stars in its central
portion, while star formation continues in the outer, bluer spiral arms. The
brightest of these young, blue stars can be seen individually in this
high-resolution view from Hubble's Advanced Camera for Surveys (ACS).
One atypical feature of this Hubble image is the view of supernova SN 2006bc
taken when its brightness was on the decrease. Astronomers at Queen's
University Belfast in Northern Ireland, led by Professor of Astronomy
Stephen J. Smartt, requested the image as part of a long project studying
massive exploding stars -- supernovae. Exactly which types of stars will
explode and the lowest mass of star that can produce a supernova are not
known.
When a supernova is discovered in a nearby galaxy, the group begins a
painstaking search of earlier Hubble images of the same galaxy to locate the
star that exploded later; often one of hundreds of millions of stars in the
galaxy. This is a little like sifting through days of CCTV footage to find
one frame showing a suspect.
If the astronomers find a star at the location of the later explosion, they
may work out the mass and type of star from its brightness and colour. Only
six such stars have been identified before they exploded and Smartt's team
have discovered the nature of five of them.
In their latest work on Hubble images, to be presented at the UK National
Astronomy Meeting 2008 in Belfast, the team reveals the results of their
ten-year search for these elusive supernova precursor stars. It seems that
stars with masses as low as seven times the mass of the Sun can explode as
supernovae. The team have not found any very massive stars that exploded,
suggesting that the most massive stars may collapse to form black holes
either without producing a supernova or by producing one that is too faint
to observe. This intriguing possibility will be discussed at the meeting.
A public lecture at Queen's University Belfast showing how the Hubble Space
Telescope has built a bridge between science and art will coincide with a
presentation of the latest scientific study of Hubble galaxy images by
astronomers at the university. The images were obtained on 14 October 2006
with Hubble's Advanced Camera for Surveys (ACS) with three different colour
filters (blue, green and near-infrared).
Notes for editors:
The Hubble Space Telescope is a project of international cooperation between
NASA and ESA.
The Royal Astronomical Society National Astronomy Meeting (NAM) 2008 will
take place at Queen's University Belfast from 31 March to 4 April.
For more information:
Lars Lindberg Christensen, Hubble/ESA, Garching, Germany
E-mail: Lars @ eso.org
Prof. Stephen Smartt, Queen's University Belfast
E-mail: S.Smartt @ qub.ac.uk
[NOTE: Images and weblinks supporting this release are available at
http://www.esa.int/esaSC/SEMSPG5QGEF_index_1.html ]