SOPHIE velocimetry of<i>Kepler</i>transit candidates

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

doi:10.1051/0004-6361/201424406

Cited by 46 publications

(35 citation statements)

References 56 publications

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“…The other two massive substellar companions in our sample (KOI-205 b (∼40 M ) and KOI-415 b (∼62 M ): Díaz et al 2013;Moutou et al 2013a) are very likely to be brown dwarfs. Finally, the case of the 78 Mcompanion to KOI-189 has been classified as a very-low-mass star by Díaz et al (2014b). This leads to a total number of bona fide EGPs in our candidate sample of 45 and 3 brown dwarfs.…”

Section: Bona Fide Planets and Brown Dwarfsmentioning

confidence: 99%

SOPHIE velocimetry ofKeplertransit candidates

Santerne

Moutou

Tsantaki

et al. 2016

A&A

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While giant extrasolar planets have been studied for more than two decades now, there are still some open questions as to their dominant formation and migration processes, as well as to their atmospheric evolution in different stellar environments. In this paper, we study a sample of giant transiting exoplanets detected by the Kepler telescope with orbital periods up to 400 days. We first defined a sample of 129 giant-planet candidates that we followed up with the SOPHIE spectrograph (OHP, France) in a 6-year radial velocity campaign. This allowed us to unveil the nature of these candidates and to measure a false-positive rate of 54.6 ± 6.5% for giant-planet candidates orbiting within 400 days of period. Based on a sample of confirmed or likely planets, we then derived the occurrence rates of giant planets in different ranges of orbital periods. The overall occurrence rate of giant planets within 400 days is 4.6 ± 0.6%. We recovered, for the first time in the Kepler data, the different populations of giant planets reported by radial velocity surveys. Comparing these rates with other yields, we find that the occurrence rate of giant planets is lower only for hot Jupiters but not for the longer-period planets. We also derive a first measurement of the occurrence rate of brown dwarfs in the brown-dwarf desert with a value of 0.29 ± 0.17%. Finally, we discuss the physical properties of the giant planets in our sample. We confirm that giant planets receiving moderate irradiation are not inflated, but we find that they are on average smaller than predicted by formation and evolution models. In this regime of low-irradiated giant planets, we find a possible correlation between their bulk density and the iron abundance of the host star, which needs more detections to be confirmed.

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Section: Bona Fide Planets and Brown Dwarfsmentioning

confidence: 99%

SOPHIE velocimetry ofKeplertransit candidates

Santerne

Moutou

Tsantaki

et al. 2016

A&A

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264

263

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“…4). ( ‡) In this case, the radius of the companion was obtained from Díaz et al (2014). (d) In Sect.…”

Section: Cafe Observations and Data Reductionmentioning

confidence: 99%

Eclipsing binaries and fast rotators in theKeplersample

Lillo-Box

Barrado

Mancini

et al. 2015

A&A

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Context. The Kepler mission has searched for planetary transits in more than two hundred thousand stars by obtaining very accurate photometric data over a long period of time. Among the thousands of detected candidates, the planetary nature of around 15% has been established or validated by different techniques. But additional data are needed to characterize the rest of the candidates and reject other possible configurations. Aims. We started a follow-up program to validate, confirm, and characterize some of the planet candidates. In this paper we present the radial velocity analysis of those that present large variations, which are compatible with being eclipsing binaries. We also study those showing high rotational velocities, which prevents us from reaching the necessary precision to detect planetary-like objects. Methods. We present new radial velocity results for 13 Kepler objects of interest (KOIs) obtained with the CAFE spectrograph at the Calar Alto Observatory and analyze their high-spatial resolution (lucky) images obtained with AstraLux and the Kepler light curves of some interesting cases. Results. We have found five spectroscopic and eclipsing binaries (group A). Among them, the case of KOI-3853 is of particular interest. This system is a new example of the so-called heartbeat stars, showing dynamic tidal distortions in the Kepler light curve. We have also detected duration and depth variations of the eclipse. We suggest possible scenarios to explain such an effect, including the presence of a third substellar body possibly detected in our radial velocity analysis. We also provide upper mass limits to the transiting companions of six other KOIs with high rotational velocities (group B). This property prevents the radial velocity method from achieving the necessary precision to detect planetary-like masses. Finally, we analyze the large radial velocity variations of two other KOIs, which are incompatible with the presence of planetary-mass objects (group C). These objects are likely to be stellar binaries. However, a longer timespan is needed to complete their characterization.

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“…Radial velocity measurements are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/608/A129 around 2 R Jup (Sato et al 2005;Anderson et al 2010), a range in size which also corresponds to late M dwarfs with masses lower than ∼0.2 M (Chabrier & Baraffe 1997;Baraffe et al 1998Baraffe et al , 2015Dotter et al 2008;Demory et al 2009;Díaz et al 2014;Hatzes & Rauer 2015;Chen & Kipping 2017). To further the comparison, gas giants, brown dwarfs, and very low-mass stars also have similar temperatures in addition to similar sizes.…”

Section: Introductionmentioning

confidence: 99%

The EBLM Project

Triaud

Martin

Ségransan

et al. 2017

A&A

125

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We present 2271 radial velocity measurements taken on 118 single-line binary stars, taken over eight years with the CORALIE spectrograph. The binaries consist of F/G/K primaries and M dwarf secondaries. They were initially discovered photometrically by the WASP planet survey, as their shallow eclipses mimic a hot Jupiter transit. The observations we present permit a precise characterisation of the binary orbital elements and mass function. With modelling of the primary star, this mass function is converted to a mass of the secondary star. In the future, this spectroscopic work will be combined with precise photometric eclipses to draw an empirical mass/radius relation for the bottom of the mass sequence. This has applications in both stellar astrophysics and the growing number of exoplanet surveys around M dwarfs. In particular, we have discovered 34 systems with a secondary mass below 0.2 M , and so we will ultimately double the number of known very low-mass stars with well-characterised masses and radii. The quality of our data combined with the amplitude of the Doppler variations mean that we are able to detect eccentricities as small as 0.001 and orbital periods to sub-second precision. Our sample can revisit some earlier work on the tidal evolution of close binaries, extending it to low mass ratios. We find some exceptional binary systems that are eccentric at orbital periods below three days, while our longest circular orbit has a period of 10.4 days. Amongst our systems, we note one remarkable architecture in J1146-42 that boasts three stars within one astronomical unit. By collating the EBLM binaries with published WASP planets and brown dwarfs, we derive a mass spectrum with twice the resolution of previous work. We compare the WASP/EBLM sample of tightly bound orbits with work in the literature on more distant companions up to 10 AU. We note that the brown dwarf desert appears wider, as it carves into the planetary domain for our short-period orbits. This would mean that a significantly reduced abundance of planets begins at ∼3 M Jup , well before the deuterium-burning limit. This may shed light on the formation and migration history of massive gas giants.

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SOPHIE velocimetry ofKeplertransit candidates

Cited by 46 publications

References 56 publications

SOPHIE velocimetry ofKeplertransit candidates

SOPHIE velocimetry ofKeplertransit candidates

Eclipsing binaries and fast rotators in theKeplersample

The EBLM Project

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