* Astronomy

Title: KOI-200b and KOI-889b: two transiting exoplanets detected and characterised with Kepler, SOPHIE and HARPS-N
Authors: G. Hebrard, J.-M. Almenara, A. Santerne, M. Deleuil, C. Damiani, A.S. Bonomo, F. Bouchy, G. Bruno, R.F. Diaz, G. Montagnier, C. Moutou

We present the detection and characterisation of the two new transiting, close-in, giant extrasolar planets KOI-200b and KOI-889b. 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 characterised. The planet KOI-200b has mass and radius of 0.68 ± 0.09 Jupiter masses and 1.32 ± 0.14 Jupiter radii; it orbits in 7.34 days a F8V host star with mass and radius of 1.40 (+0.14/-0.11) solar masses and 1.51 ± 0.14 solar radii. KOI-889b is a massive planet with mass and radius of 9.9 ± 0.5 Jupiter masses and 1.03 ± 0.06 Jupiter radii; 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 solar masses and 0.88 ± 0.04 solar radii. Both planets lie on eccentric orbits and are located just at the frontier between regimes where the tides can explain circularisation and where tidal effects are negligible. The two planets are among the first ones detected and characterised 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.

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