Researchers have discovered 122 new eclipsing binary stars and observed hundreds more variable stars in an innovative survey using NASA's two STEREO solar satellites. The survey has been carried out by team from the Open University, University of Central Lancashire and the STFC Rutherford Appleton Laboratory. Dr Danielle Bewsher will present highlights at the RAS National Astronomy Meeting in Llandudno, Wales on Tuesday 19th April.
STEREO was launched in 2006 to study the Sun in 3D and coronal mass ejections, the cause of space weather. Each STEREO spacecraft carries a Heliospheric Imager (HI), each instrument comprising two cameras (HI-1 and HI-2) built and developed at the STFC's Rutherford Appleton Laboratory and the University of Birmingham. The HI cameras are able to make such stable measurements that researchers can accurately monitor the brightness of stars in the background.
"Although STEREO is primarily a solar mission, we recognised that the stability of the HI cameras could also be used to monitor variations of the brightness of stars," said Bewsher, of the University of Central Lancashire. "To date, 893 000 stars have passed through the HI-1 field-of-view alone, producing an unexpected resource of scientific data about the variability of stars that is currently being data mined."
The lead author, Karl Wraight, an STFC PhD student at the OU, has found the 122 new eclipsing binaries during an initial analysis of the data, and expects many more to be discovered.
"STEREO's ability to sample continuously for up to 20 days, coupled with repeat viewings from the twin spacecraft during the year, makes it an invaluable resource for researching variable stars. As well as making discoveries, observations from HI are enabling us to pin down the periods of known variables with much greater accuracy," said Wraight.
In addition to studying variable stars, the team believes that HI measurements may be used for exoplanet and astroseismology research.
"Very small changes to the brightnesses of stars can be detected, which could reveal the presence of transiting exoplanets, or be used to trace a star’s internal structure by measuring their seismic activity," said Professor Glenn White (RAL and OU).
Dr Danielle Bewsher
University of Central Lancashire
Mob: 0771 889 7727
Dr Bewsher can be contacted through the NAM 2011 Press Office on Monday 18th and Tuesday 19th April.
Professor Glenn White
Rutherford Appleton Laboratory/Open University
Mob: 0771 423 4897
NAM 2011 Press Office (0900 – 1730 BST, 18-21 April only)
Venue Cymru conference centre
Tel: +44 (0)1492 873 637, +44 (0)1492 873 638
Dr Robert Massey
Royal Astronomical Society
Mob: +44 (0)794 124 8035
Royal Astronomical Society
Mob: +44 (0)7756 034 243
Images and an animation can be found at: http://www.star.uclan.ac.uk/~db/nam.html
Image caption: A STEREO/HI-1A image taken on 7th March 2010 (left) with two variable stars highlighted in the image. The varying brightness of the two stars, V837 Tau and V1129 Tau are shown (right top and bottom, respectively).
Image credit: Image produced by D. Bewsher (UCLan). Data courtesy of NASA/STEREO and the HI instrument team.
NOTES FOR EDITORS
Bringing together around 500 astronomers and space scientists, the RAS National Astronomy Meeting 2011 (NAM 2011: http://www.ras.org.uk/nam-2011) will take place from 17-21 April in Venue Cymru (http://www.venuecymru.co.uk), Llandudno, Wales. The conference is held in conjunction with the UK Solar Physics (UKSP: http://www.uksolphys.org) and Magnetosphere Ionosphere and Solar-Terrestrial Physics (MIST: http://www.mist.ac.uk) meetings. NAM 2011 is principally sponsored by the RAS and the Science and Technology Facilities Council (STFC: http://www.stfc.ac.uk).
The Royal Astronomical Society
The Royal Astronomical Society (RAS: http://www.ras.org.uk), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organizes scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 3500 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.
The Science and Technology Facilities Council
The Science and Technology Facilities Council (STFC: http://www.stfc.ac.uk) ensures the UK retains its leading place on the world stage by delivering world-class science; accessing and hosting international facilities; developing innovative technologies; and increasing the socio-economic impact of its research through effective knowledge exchange. The Council has a broad science portfolio including Astronomy, Particle Astrophysics and Space Science. In the area of astronomy it funds the UK membership of international bodies such as the European Southern Observatory.
Venue Cymru (http://www.venuecymru.co.uk) is a purpose built conference centre and theatre with modern facilities for up to 2000 delegates. Located on the Llandudno promenade with stunning sea and mountain views; Venue Cymru comprises a stunning location, outstanding quality and exceptional value: the perfect conference package.