New parameters and transit timing studies for OGLE2-TR-L9 b*
Max Planck Institute for Astronomy,
2 Universitäts-Sternwarte München, Scheinerstr. 1, 81679 Munich, Germany
3 Institut für Astronomie, Universität Wien, Türkenschanzstr. 17, 1180 Wien, Austria
4 Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, USA
5 Observatoire de Genève, Université de Genève, 51 chemin des Maillettes, 1290 Versoix, Switzerland
6 Max Planck Institute for Extraterrestrial Physics, Giessenbachstr., 85748 Garching, Germany
Accepted: 22 June 2010
Context. Repeated observations of exoplanet transits allow us to refine the planetary parameters and probe them for any time dependent variations. In particular deviations of the period from a strictly linear ephemeris, transit timing variations (TTVs), can indicate the presence of additional bodies in the planetary system.
Aims. Our goal was to reexamine the largely unstudied OGLE2-TR-L9 system with high cadence, multi-color photometry in order to refine the planetary parameters and probe the system for TTVs.
Methods. We observed five full transits of OGLE2-TR-L9 with the GROND instrument at the ESO/MPG 2.2 m telescope at La Silla Observatory. GROND is a multichannel imager that allowed us to gather simultaneous light curves in the g′, r′, i′, and z′ filters.
Results. From our analysis we find that the semi-major axis and the inclination differ from the previously published values. With the newly observed transits, we were able to refine the ephemeris to 2454492.80008(±0.00014) + 2.48553417(±6.4 × 10-7)E. The newly derived parameters are a = 0.0418 ± 0.0015 AU, rp = 1.67 ± 0.05 Rj, and inc = 82.47° ± 0.12, differing significantly in a and inc from the previously published values. Within our data, we find indications for TTVs.
Key words: techniques: photometric / planetary systems / planets and satellites: individual: OGLE2-TR-L9 b
Photometric data are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (22.214.171.124) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/522/A29
© ESO, 2010