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.
Issued by RAS Press Officers:
Anita Heward
Tel: +44 (0)1483-420904
Mobile: +44 (0)7756-034243
E-mail: anitaheward@btinternet.com
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
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 (link opens in a new window)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.
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 (link opens in a new window) 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
Telescope.
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 Science and Technology Facilities Council-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.
Dr Chris Wareing
School of Physics and Astronomy
The University of Manchester
Campus North
P.O. Box 88
Manchester
M60 1QD
E-mail: c.j.wareing@manchester.ac.uk
Tel: +44 (0) 7880 806 416
From Monday 16th to Tuesday 17th April, Dr Wareing can be contacted via
the
NAM Press Office (see details at top).
IPHAS: Principal Investigator and primary contact
Professor Janet Drew
Blackett Laboratory
Imperial College London
Exhibition Road
London
SW7 2AZ
E-mail: j.drew@imperial.ac.uk
Tel: 0044 (0) 207 594 7553
Fax: 0044 (0) 207 594 7541
