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Posts: 131433
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RE: SuperWASP
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Title: Accurate spectroscopic parameters of WASP planet host stars
Authors: Amanda P. Doyle, B. Smalley, P. F. L. Maxted, D. R. Anderson, A. Collier Cameron, M. Gillon, C. Hellier, D. Pollacco, D. Queloz, A. H. M. J. Triaud, R. G. West

We have made a detailed spectral analysis of eleven Wide Angle Search for Planets (WASP) planet host stars using high signal-to-noise (S/N) HARPS spectra. Our line list was carefully selected from the spectra of the Sun and Procyon, and we made a critical evaluation of the atomic data. The spectral lines were measured using equivalent widths. The procedures were tested on the Sun and Procyon prior to be being used on the WASP stars. The effective temperature, surface gravity, microturbulent velocity and metallicity were determined for all the stars. We show that abundances derived from high S/N spectra are likely to be higher than those obtained from low S/N spectra, as noise can cause the equivalent width to be underestimated. We also show that there is a limit to the accuracy of stellar parameters that can be achieved, despite using high S/N spectra, and the average uncertainty in effective temperature, surface gravity, microturbulent velocity and metallicity is 83 K, 0.11 dex, 0.11 km/s and 0.10 dex respectively.

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Posts: 131433
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SuperWASP exoplanetary transit-search programme
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Title: Stellar rotation in the Hyades and Praesepe: gyrochronology and braking timescale
Authors: Delorme, P.; Collier Cameron , A.; Hebb, L.; Rostron, J.; Lister, T. A.; Norton, A. J.; Pollacco, D. and West, R. G.

We present the results of photometric surveys for stellar rotation in the Hyades and in Praesepe, using data obtained as part of the SuperWASP exoplanetary transit-search programme. We determined accurate rotation periods for more than 120 sources whose cluster membership was confirmed by common proper motion and colour-magnitude fits to the clusters' isochrones. This allowed us to determine the effect of magnetic braking on a wide range of spectral types for expected ages of ~600 Myr for the Hyades and Praesepe. Both clusters show a tight and nearly linear relation between J-Ks colour and rotation period in the F,G and K spectral range. This confirms that loss of angular momentum was significant enough that stars with strongly different initial rotation rates have converged to the same rotation period for a given mass, by the age of Hyades and Praesepe. In the case of the Hyades our colour-period sequence extends well into the M dwarf regime and shows a steep increase in the scatter of the colour-period relation, with identification of numerous rapid rotators from ~0.5 solar masses down to the lowest masses probed by our survey(~0.25 solar masses). This provides crucial constraints on the rotational braking timescales and further clears the way to use gyrochronology as an accurate age measurement tool for main-sequence stars.

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Posts: 131433
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WASP survey
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Title: Detection limits for close eclipsing and transiting sub-stellar and planetary companions to white dwarfs in the WASP survey
Authors: F. Faedi, R. G. West, M. R. Burleigh, M. R. Goad, L. Hebb

We have performed extensive simulations to explore the possibility of detecting eclipses and transits of close, sub-stellar and planetary companions to white dwarfs in WASP light-curves. Our simulations cover companions \sim0.3\Re< R_pl<12\Re and orbital periods 2 h<P<15 d, equivalent to orbital radii 0.003 AU < a < 0.1 AU. For Gaussian random noise WASP is sensitive to transits by companions as small as the Moon orbiting a V\simeq12 white dwarf. For fainter white dwarfs WASP is sensitive to increasingly larger radius bodies. However, in the presence of correlated noise structure in the light-curves the sensitivity drops, although Earth-sized companions remain detectable in principle even in low S/N data. Mars-sized, and even Mercury-sized bodies yield reasonable detection rates in high-quality light-curves with little residual noise. We searched for eclipses and transit signals in long-term light-curves of a sample of 194 white dwarfs resulting from a cross-correlation of the McCook & Sion catalogue and the WASP archive. No evidence for eclipsing or transiting sub-stellar and planetary companions was found. We used this non-detection and results from our simulations to place tentative upper limits to the frequency of such objects in close orbits at white dwarfs. While only weak limits can be placed on the likely frequency of Earth-sized or smaller companions, brown dwarfs and gas giants (radius \approx \Rjup) with periods <0.1-0.2~days must certainly be rare (<10%). More stringent constraints likely requires significantly larger white dwarf samples, higher observing cadence and continuous coverage. The short duration of eclipses and transits of white dwarfs compared to the cadence of WASP observations appears to be one of the main factors limiting the detection rate in a survey optimised for planetary transits of main sequence stars.

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Posts: 131433
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SuperWASP search
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Title: A SuperWASP search for additional transiting planets in 24 known systems
Authors: A. M. S. Smith, L. Hebb, A. Collier Cameron, D. R. Anderson, T. A. Lister, C. Hellier, D. Pollacco, D. Queloz, I. Skillen, R. G. West

We present results from a search for additional transiting planets in 24 systems already known to contain a transiting planet. We model the transits due to the known planet in each system and subtract these models from lightcurves obtained with the SuperWASP survey instruments. These residual lightcurves are then searched for evidence of additional periodic transit events. Although we do not find any evidence for additional planets in any of the planetary systems studied, we are able to characterise our ability to find such planets by means of Monte Carlo simulations. Artificially generated transit signals corresponding to planets with a range of sizes and orbital periods were injected into the SuperWASP photometry and the resulting lightcurves searched for planets. As a result, the detection efficiency as a function of both the radius and orbital period of any second planet, is calculated. We determine that there is a good (> 50 per cent) chance of detecting additional, Saturn-sized planets in P ~ 10 d orbits around planet-hosting stars that have several seasons of SuperWASP photometry. Additionally, we confirm previous evidence of the rotational stellar variability of WASP-10, and refine the period of rotation. We find that the period of the rotation is 11.91 ± 0.05 d, and the false alarm probability for this period is extremely low (~ 10^{-13}).

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Posts: 131433
Date:
RE: SuperWASP
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SuperWASP is one of the instruments to detect extrasolar planets for greater success in the world. With only four years of life has already discovered a total of 24 celestial objects.

Not a bird, nor a plane, SuperWASP is a small telescope designed to detect extrasolar planets orbiting bright stars.
It does not have cutting-edge technology, nor is it the most innovative. It does not draw attention for being spectacular, not even for being large, but SuperWasp has become one of the greatest discoverers of planets in the universe. Located at the Observatory del Roque de los Muchachos (ORM), on the island of La Palma, and alongside a counterpart from the South African Astronomical Observatory, it is operated continuously throughout the year tracking the visible sky in the northern and southern hemisphere. So far, this system has found a total of 24 extrasolar planets - a real success.

"Debido a su gran campo de visión, SuperWASP puede hacer una imagen de todo el cielo visible en aproximadamente 23 minutos" - Don Pollaco, Principle project investigator, Queen's University Belfast.

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Posts: 131433
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SuperWASP Astronomers Funded
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Astronomers in the Astrophysics Research Centre (ARC) of the School of Mathematics and Physics have been awarded grants totalling 3 million pounds for their research programmes.
The largest award - of 2.2 million pounds - is from the Science and Technology Facilities Council (STFC) to support a range of astronomical research programmes within ARC for the 5-year period 2008 to 2013. These include studies of our Sun and other stars, the search for planets orbiting stars other than the Sun (the so-called exoplanets), investigations of supernovae (stars which end their lives in massive explosions), the detection and study of comets and asteroids, and the investigation of chemical processes in material from which stars form.

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Posts: 131433
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RE: SuperWASP
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Recently astronomers reported the discovery of 10 extrasolar planets trillions of miles from Earth. That boosts the roster of alien planets to 287 since the first two were identified in 1996.
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The SuperWasp Factory Finds 10 New Planets In The Last 6 Months.
In the last 6 months an international team of astronomers have used two batteries of cameras, one in the Canary Islands and one in South Africa, to discover 10 new planets in orbit around other stars (commonly known as extrasolar planets). The results from the Wide Area Search for Planets (SuperWASP) will be announced by team member Dr Don Pollacco of Queens University Belfast, in his talk at the RAS National Astronomy Meeting (NAM 2008) on Tuesday 1 April.

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SuperWASP-N
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Title: SuperWASP-N Extra-solar Planet Candidates from Fields 06hr < RA < 16hr
Authors: S.R. Kane, W.I. Clarkson, R.G. West, D.M. Wilson, D.J. Christian, A. Collier Cameron, B. Enoch, T.A. Lister, R.A. Street, A. Evans, A. Fitzsimmons, C.A. Haswell, C. Hellier, S.T. Hodgkin, K. Horne, J. Irwin, F.P. Keenan, A.J. Norton, J. Osborne, N.R. Parley, D.L. Pollacco, R. Ryans, I. Skillen, P.J. Wheatley

The Wide Angle Search for Planets (WASP) survey currently operates two installations, designated SuperWASP-N and SuperWASP-S, located in the northern and southern hemispheres respectively. These installations are designed to provide high time-resolution photometry for the purpose of detecting transiting extra-solar planets, asteroids, and transient events. Here we present results from a transit-hunting observing campaign using SuperWASP-N covering a right ascension range of 06hr < RA < 16hr. This paper represents the fifth and final in the series of transit candidates released from the 2004 observing season. In total, 729,335 stars from 33 fields were monitored with 130,566 having sufficient precision to be scanned for transit signatures. Using a robust transit detection algorithm and selection criteria, 6 stars were found to have events consistent with the signature of a transiting extra-solar planet based upon the photometry, including the known transiting planet XO-1b. These transit candidates are presented here along with discussion of follow-up observations and the expected number of candidates in relation to the overall observing strategy.

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RE: SuperWASP
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Finding another Earth outside our solar system would be big news - but there are some surprising discoveries in our very own cosmic backyard. We catch up with some amazing findings in our solar system and beyond and unveil the chances of finding another earth and, possibly, life elsewhere in the Cosmos.
Adam Hart-Davis presents this programme from a spectacular location - the summit of an extinct volcano at La Palma in the Canary Islands. Its one of the worlds best places for star gazing and is home to some hugely impressive telescopes. But our story starts with an instrument that could fit in your shed at home. Although its small, its hugely powerful and holds the key to finding worlds outside our solar system.
Adam meets Dr Don Pollacco of Queens University Belfast, the astronomer who led the team who built this amazing telescope, called SuperWASP. WASP stands for Wide Angle Search for Planets. And SuperWASP here has actually found other worlds orbiting, not our sun, but other stars - the so called exoplanets. Dons telescope uses the transit method to find other worlds, measuring the dip in the light as a planet orbits its sun.

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