International Journal of Astrobiology



Looking towards the detection of exoearths with SuperWASP


R.A. Street a1, D.J. Christian a1, W.I. Clarkson a2a3, A.C. Cameron a4, B. Enoch a2, A. Evans a2, A. Fitzsimmons a1, C.A. Haswell a2, C. Hellier a5, S.T. Hodgkin a6, Keith Horne a4, J. Irwin a6, F.P. Keenan a1, S.R. Kane a4a7, T.A. Lister a4a5, A.J. Norton a2, J. Osborne a9, D. Pollacco a1, R. Ryans a1, I. Skillen a8, R.G. West a9, P.J. Wheatley a9a10 and D. Wilson a5
a1 Astrophysics Research Centre, School of Mathematics and Physics, Queen's University, University Road, Belfast, BT7 1NN, UK e-mail: r.street@qub.ac.uk
a2 Department of Physics & Astronomy, The Open University, Milton Keynes, MK7 6AA, UK
a3 Space Telescope Science Institute (STScI), 3700 San Martin Drive, Baltimore, MD 21218, USA
a4 School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9SS, UK
a5 Astrophysics Group, School of Chemistry & Physics, Keele University, Staffordshire, ST5 5BG, UK
a6 Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA, UK
a7 Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055, USA
a8 Isaac Newton Group of Telescopes, Apartado de correos 321, E-38700 Santa Cruz de la Palma, Tenerife, Spain
a9 Department of Physics & Astronomy, University of Leicester, Leicester, LE1 7RH, UK
a10 Department of Physics, University of Warwick, Coventry CV4 7AL, UK

Article author query
street ra   [PubMed][Google Scholar] 
christian dj   [PubMed][Google Scholar] 
clarkson wi   [PubMed][Google Scholar] 
cameron ac   [PubMed][Google Scholar] 
enoch b   [PubMed][Google Scholar] 
evans a   [PubMed][Google Scholar] 
fitzsimmons a   [PubMed][Google Scholar] 
haswell ca   [PubMed][Google Scholar] 
hellier c   [PubMed][Google Scholar] 
hodgkin st   [PubMed][Google Scholar] 
horne k   [PubMed][Google Scholar] 
irwin j   [PubMed][Google Scholar] 
keenan fp   [PubMed][Google Scholar] 
kane sr   [PubMed][Google Scholar] 
lister ta   [PubMed][Google Scholar] 
norton aj   [PubMed][Google Scholar] 
osborne j   [PubMed][Google Scholar] 
pollacco d   [PubMed][Google Scholar] 
ryans r   [PubMed][Google Scholar] 
skillen i   [PubMed][Google Scholar] 
west rg   [PubMed][Google Scholar] 
wheatley pj   [PubMed][Google Scholar] 
wilson d   [PubMed][Google Scholar] 

Abstract

The WASP consortium is conducting an ultra-wide field survey of stars between 8–15 mag from both hemispheres. Our primary science goal is to detect extra-solar ‘hot-Jupiter’-type planets that eclipse (or transit) bright host stars and for which further detailed investigation will be possible. We summarize the design of the SuperWASP instruments and describe the first results from our northern station SW-N, sited in La Palma, Canary Islands. Our second station, which began operations this year, is located at the South African Astronomical Observatory. Between April and September, 2004, SW-N continuously observed ~6.7 million stars. The consortium's custom-written, fully automated data reduction pipeline has been used to process these data, and the information is now stored in the project archive, held by the Leicester database and archive service (LEDAS). We have applied a sophisticated, automated algorithm to identify the low-amplitude (~0.01 mag), brief (~few hours) signatures of transiting exoplanets. In addition, we have assessed each candidate in the light of all available catalogue information in order to reject data artefacts and astrophysical false positive detections. The highest priority candidates are currently being subjected to further observations in order to select the true planets. Once the exoplanets are confirmed, a host of exciting opportunities are open to us. In this paper, we describe two techniques that exploit the transits in order to detect other objects within the same system. The first involves determining precise epochs for a sequence of transit events in order to detect the small timing variations caused by the gravitational pull of other planets in the same system. The second method employs ultra-high precision photometry of the transits to detect the deviations caused by the presence of exoplanetary moons. Both of these techniques are capable of detecting objects the size of terrestrial planets.

(Published Online September 18 2006)
(Received June 26 2006)
(Accepted August 6 2006)


Key Words: Extra-solar planets; planetary transits.