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Centro de Astrofísica da Universidade do Porto

KOI-200 b and KOI-889 b: two transiting exoplanets detected and characterized with Kepler, SOPHIE and HARPS-N

G. Hébrard, J.-M. Almenara, A. Santerne, M. Deleuil, C. Damiani, A. S. Bonomo, F. Bouchy, G. Bruno, R. F. Díaz, G. Montagnier, C. Moutou

We present the detection and characterization of the two new transiting, close-in, giant extrasolar planets KOI-200 b and KOI-889 b. They were first identified by the Kepler team as promising candidates from photometry of the Kepler satellite, then we established their planetary nature thanks to the radial velocity follow-up jointly secured with the spectrographs SOPHIE and HARPS-N. Combined analyses of the whole datasets allow the two planetary systems to be characterized. The planet KOI-200 b has mass and radius of 0.68 ± 0.09 MJup and 1.32 ± 0.14 RJup; it orbits in 7.34 days a F8V host star with mass and radius of 1.40+0.14-0.11 M and 1.51 ± 0.14 R. KOI-889 b is a massive planet with mass and radius of 9.9±0.5MJup and 1.03±0.06 RJup; it orbits in 8.88 days an active G8V star with a rotation period of 19:2±0.3 days, and mass and radius of 0.88±0.06 M and 0.88±0.04 R. Both planets lie on eccentric orbits and are located just at the frontier between regimes where the tides can explain circularization and where tidal effects are negligible. The two planets are among the first ones detected and characterized thanks to observations secured with HARPS-N, the new spectrograph recently mounted at the Telescopio Nazionale Galileo. These results illustrate the benefits that could be obtained from joint studies using two spectrographs as SOPHIE and HARPS-N.

planets and satellites: detection – techniques: photometric – techniques: radial velocities – techniques: spectroscopic – stars: individual: KOI-200 (Kepler-74) – stars: individual: KOI-889 (Kepler-75)

Astronomy and Astrophysics
Volume 554, Page A114_1
June 2013

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