binaries: eclipsing; stars: individual: WASP-2; planetary systems
Abstract :
[en] ABSTRACT We present high-precision photometry of three transits of the extrasolar planetary system WASP-2, obtained by defocusing the telescopes, and achieving scatters of between 0.42 and 0.73 mmag versus the best-fitting model. These data are modelled using the JKTEBOP code, and taking into account the light from the recently discovered faint star close to the system. The physical properties of the WASP-2 system are derived using tabulated predictions from five different sets of stellar evolutionary models, allowing both statistical and systematic error bars to be specified. We find the mass and radius of the planet to be M[SUB]b[/SUB] = 0.846 +/- 0.055 +/- 0.023M[SUB]Jup[/SUB] and R[SUB]b[/SUB] = 1.043 +/- 0.029 +/- 0.015R[SUB]Jup[/SUB]. It has a low equilibrium temperature of 1281 +/- 21K, in agreement with a recent finding that it does not have an atmospheric temperature inversion. The first of our transit data sets has a scatter of only 0.42mmag with respect to the best-fitting light-curve model, which to our knowledge is a record for ground-based observations of a transiting extrasolar planetary system. Based on data collected by MiNDSTEp with the Danish 1.54-m telescope at the ESO La Silla Observatory. E-mail: jkt@astro.keele.ac.uk ‡ Royal Society University Research Fellow.
Mancini, L.; Dipartimento di Ingegneria, Università del Sannio, Corso Garibaldi 107, 82100-Benevento, Italy ; Dipartimento di Fisica `E. R. Caianiello', Università di Salerno, Via Ponte Don Melillo, 84084-Fisciano (SA), Italy ; Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Italy ; Istituto Internazionale per gli Alti Studi Scientifici (IIASS), 84019 Vietri Sul Mare (SA), Italy
Novati, S Calchi; Dipartimento di Fisica `E. R. Caianiello', Università di Salerno, Via Ponte Don Melillo, 84084-Fisciano (SA), Italy ; Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Italy ; Istituto Internazionale per gli Alti Studi Scientifici (IIASS), 84019 Vietri Sul Mare (SA), Italy
Dominik, M.; SUPA, University of St Andrews, School of Physics & Astronomy, North Haugh, St Andrews KY16 9SS
Glitrup, M.; Department of Physics & Astronomy, Aarhus University, Ny Munkegade, 8000 Aarhus C, Denmark
Hinse, T. C.; Armagh Observatory, College Hill, Armagh BT61 9DG ; Niels Bohr Institute and Centre for Star and Planet Formation, University of Copenhagen, Juliane Maries vej 30, 2100 Copenhagen Ø, Denmark
Jørgensen, U. G.; Niels Bohr Institute and Centre for Star and Planet Formation, University of Copenhagen, Juliane Maries vej 30, 2100 Copenhagen Ø, Denmark ; Centre for Star and Planet Formation, Geological Museum, Øster Voldgade 5-7, 1350 Copenhagen, Denmark
Mathiasen, M.; Niels Bohr Institute and Centre for Star and Planet Formation, University of Copenhagen, Juliane Maries vej 30, 2100 Copenhagen Ø, Denmark
Ricci, Davide ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS)
Maier, G.; Astronomisches Rechen-Institut, Zentrum für Astronomie, Universität Heidelberg, Mönchhofstraße 12-14, 69120 Heidelberg, Germany
Zimmer, F.; Astronomisches Rechen-Institut, Zentrum für Astronomie, Universität Heidelberg, Mönchhofstraße 12-14, 69120 Heidelberg, Germany
Bozza, V.; Dipartimento di Fisica `E. R. Caianiello', Università di Salerno, Via Ponte Don Melillo, 84084-Fisciano (SA), Italy ; Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Italy ; Istituto Internazionale per gli Alti Studi Scientifici (IIASS), 84019 Vietri Sul Mare (SA), Italy
Browne, P.; SUPA, University of St Andrews, School of Physics & Astronomy, North Haugh, St Andrews KY16 9SS
Bruni, I.; INAF - Osservatorio Astronomico di Bologna, Via Ranzani 1, 40127 Bologna, Italy
Burgdorf, M.; Deutsches SOFIA Institut, Universitaet Stuttgart, Pfaffenwaldring 31, 70569 Stuttgart, Germany ; Deutsches SOFIA Institut, NASA Ames Research Center, Mail Stop 211-3, Moffett Field, CA 94035, USA
Dall'Ora, M.; INAF - Osservatorio Astronomico di Capodimonte, Via Moiarello 16, 80131 Napoli, Italy
Finet, François ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS)
Harpsøe, K.; Niels Bohr Institute and Centre for Star and Planet Formation, University of Copenhagen, Juliane Maries vej 30, 2100 Copenhagen Ø, Denmark
Hundertmark, M.; Institut für Astrophysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
Liebig, C.; Astronomisches Rechen-Institut, Zentrum für Astronomie, Universität Heidelberg, Mönchhofstraße 12-14, 69120 Heidelberg, Germany
Rahvar, S.; Department of Physics, Sharif University of Technology, PO Box 11155-9161, Tehran, Iran
Scarpetta, G.; Dipartimento di Fisica `E. R. Caianiello', Università di Salerno, Via Ponte Don Melillo, 84084-Fisciano (SA), Italy ; Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Italy ; Istituto Internazionale per gli Alti Studi Scientifici (IIASS), 84019 Vietri Sul Mare (SA), Italy
Skottfelt, J.; Niels Bohr Institute and Centre for Star and Planet Formation, University of Copenhagen, Juliane Maries vej 30, 2100 Copenhagen Ø, Denmark
Snodgrass, C.; European Southern Observatory, Casilla 19001, Santiago 19, Chile ; Max-Planck-Institute for Solar System Research, Max-Planck Str. 2, 37191 Katlenburg-Lindau, Germany
Surdej, Jean ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS)
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