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Astronomers based at Jodrell Bank Observatory have found
evidence that giant whirlpools form in the wake of stars as
they move through clouds in interstellar space. The
discovery will be presented by Dr Chris Wareing at the Royal
Astronomical Society’s National Astronomy Meeting in Preston
on 17th April.
ROYAL ASTRONOMICAL SOCIETY PRESS INFORMATION
NOTE:
EMBARGOED FOR 00:01 BST, TUESDAY, 17 APRIL 2007
Ref.: PN 07/14 (NAM10)
Issued by RAS Press
Officers:
AND
Robert Massey Tel: +44 (0)20 7734 4582 Mobile:
+44 (0)794 124 8035 E-mail: rm@ras.org.uk NATIONAL
ASTRONOMY MEETING PRESS ROOM (16 - 20 APRIL ONLY): Tel: +44
(0) 1772 892613 (0)1772 892475 (0)1772 892477
CONTACT DETAILS ARE LISTED AT THE END OF THIS
RELEASE.
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DYING
SUN-LIKE STARS LEAVE WHIRLPOOLS IN THEIR WAKE
Astronomers based at Jodrell Bank Observatory have
found evidence that giant whirlpools form in the wake of stars
as they move through clouds in interstellar space. The
discovery will be presented by Dr Chris Wareing at the Royal
Astronomical Society’s National Astronomy Meeting in Preston
on 17th April.
Dr Wareing and his colleagues used the COBRA
supercomputer to simulate in three-dimensions the movement of
a dying star through surrounding interstellar gas. At the end
of their life, Sun-sized stars lose their grip on their outer
layers and as much as half of their mass drifts off into
space. The computer simulation modelled the collision between
material given off by the star and the interstellar gas.
It showed that a shockwave forms ahead of the dying star and
giant eddies and whirlpools develop in the tail of material
behind the star, similar to those seen in the wake of boats on
open water. The group have now backed up these predictions
with observations of the planetary nebula Sharpless 2-188
taken as part of the IPHAS (Isaac Newton Telescope Photometric
H alpha Survey of the Northern Galactic Plane).
The central star of Sharpless 2-188 is 850 light
years away and it is travelling at 125 kilometres per second
across the sky. Observations show a strong brightening in the
direction in which the star is moving and faint material
stretching away in the opposite direction. Dr Wareing believes
that the bright structures in the arc observed ahead of
Sharpless 2-188 are the bowshock instabilities revealed in his
simulations, which will form whirlpools as they spiral past
the star downstream to the tail.
"These vortices can improve the mixing of the stellar
material back into interstellar space, benefiting the next
cycle of star formation. The turbulent whirlpools have an
inherent spin, or angular momentum, which is an essential
ingredient for the formation of the next generation of stars."
said Dr Wareing who developed the computer model during his
PhD and is now using it to understand the fate of our
Sun.
Dying stars eject both gas and dust into space. The
dust will coalesce into planets around later generations of
stars. The gas contains carbon, necessary for life and
produced inside stars. How the carbon, other gas and dust are
ejected from the dying star is not well understood. The
whirlpools in space can play an important role in mixing these
essential ingredients into the interstellar gas from which
further stars and planets will form.
FURTHER INFORMATION
IPHAS IPHAS is a major survey of the Northern
Galactic Plane being carried out with the 2.5-metre Isaac
Newton Telescope (INT) in La Palma. The IPHAS survey began
taking data with the INT Wide Field Camera in 2003 with the
goal of imaging the entire northern galactic plane in the
latitude range -5° < b < +5 degrees. Imaging of this
1800 sq. degree area should be completed by the end of
2007. http://www.iphas.org/
NOTES FOR EDITORS
Royal Astronomical Society’s National Astronomy
Meeting
The RAS National Astronomy Meeting is the UK's
premier meeting for the astronomy, solar system and space
science communities. The RAS-NAM 2007 is hosted by the
University of Central Lancashire and is joined by the UK Solar
Physics and Spring MIST meetings. It is sponsored by the Royal
Astronomical Society, the UK Science and Technology Facilities
Council and the University of Central Lancashire.
Jodrell Bank Observatory
The Jodrell Bank
Observatory is part of the School of Physics and Astronomy at
The University of Manchester. The Observatory is home to the
Lovell Radio Telescope and the MERLIN/VLBI National Facility
which is operated by the University on behalf of Science and
Technology Facilities Council. 2007 is the 50th
Anniversary of the Lovell Space Telescope. For details
of events, see:
IMAGES:
1) Sharpless 2-188, taken from the IPHAS
survey.
2) A detail of the bright arc of Sharpless
2-188.
3) A still from the computer simulation revealing the
vortex moving downstream.
MOVIES:
This movie is created from slices
through the computer simulation revealing the nature of the
vortex. The simulation is performed in the frame of reference
of the star and the interstellar gas is flowing in from the
top of the movie box.
CONTACT INFORMATION:
This work was carried out
by Dr Chris Wareing and collaborators as part of his
STFC-funded Ph.D. project at Jodrell Bank under the
supervision of Dr Tim O'Brien and as part of current
post-doctoral research position at the University of
Manchester.
Dr Chris Wareing is also the North West of England’s
Regional Co-ordinator for the Royal Institution's Science for
Schools programme.
From Monday 16th to Tuesday 17th April, Dr Wareing
can be contacted via the NAM Press Office (see details at
top).
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