The transiting planet OGLE-TR-132b revisited with new spectroscopy and deconvolution photometry,
Abstract
OGLE-TR-132b transits a very metal-rich F dwarf about 2000 pc from the Sun, in the Galactic disc towards Carina. It orbits very close to its host star (a = 0.03 AU) and has an equilibrium temperature of nearly 2000 K. Using rapid-cadence transit photometry from the FORS2 camera on the VLT and SUSI2 on the NTT, and high-resolution spectroscopy with UVES on the VLT, we refine the shape of the transit light curve and the parameters of the system. In particular, we improve the planetary radius estimate, R = 1.18 ± 0.07 RJ and provide very precise ephemeris, T_tr = 2 453 142.59123 ± 0.0003 BJD and P = 1.689868 ± 0.000003 days. The obtained planetary mass is 1.14 ± 0.12 M_J. Our results give a slightly smaller and lighter star, and bigger planet, than previous values. As the VLT/FORS2 light curve obtained in this analysis with the deconvolution photometry algorithm DECPHOT shows a transit depth in disagreement with the one obtained by a previous study using the same data, we analyze them with two other reduction methods (aperture and image subtraction). The light curves obtained with the three methods are in good agreement, though deconvolution-based photometry is significantly more precise. It appears from these results that the smaller transit depth obtained in the previous study was due to a normalisation problem inherent to the reduction procedure used.
Based on data collected with the FORS2 imager at the VLT-UT4 telescope (Paranal Observatory, ESO, Chile) in the programme 273.C-5017A, with the SUSI2 imager at the NTT telescope (La Silla Observatory, ESO, Chile) in the programme 075.C-0462A, and with the UVES spectrograph at the VLT-UT2 telescope (Paranal Observatory, ESO, Chile) in the programme 076.C-0131. The reduced photometric data used in this work are available only in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/466/743- Publication:
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Astronomy and Astrophysics
- Pub Date:
- May 2007
- DOI:
- 10.1051/0004-6361:20066367
- arXiv:
- arXiv:astro-ph/0702192
- Bibcode:
- 2007A&A...466..743G
- Keywords:
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- planetary systems;
- stars: individual: OGLE-TR-132;
- techniques: photometric;
- techniques: image processing;
- methods: data analysis;
- Astrophysics
- E-Print:
- 7 pages, 6 figures. Accepted for publication in A&