Precise masses for the transiting planetary system HD 106315 with HARPS
- Creators
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Barros, S. C. C.
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Shporer, A.
Abstract
Context. The multi-planetary system HD 106315 was recently found in K2 data. The planets have periods of P_b ~ 9.55 and P_c ~ 21.06 days, and radii of r_b = 2.44 ± 0.17 R⊕ and r_c = 4.35 ± 0.23 R⊕. The brightness of the host star (V = 9.0 mag) makes it an excellent target for transmission spectroscopy. However, to interpret transmission spectra it is crucial to measure the planetary masses. Aims. We obtained high precision radial velocities for HD 106315 to determine the mass of the two transiting planets discovered with Kepler K2. Our successful observation strategy was carefully tailored to mitigate the effect of stellar variability. Methods. We modelled the new radial velocity data together with the K2 transit photometry and a new ground-based partial transit of HD 106315c to derive system parameters. Results. We estimate the mass of HD 106315b to be 12.6 ± 3.2 M⊕ and the density to be 4.7 ± 1.7 g cm^(-3), while for HD 106315c we estimate a mass of 15.2 ± 3.7 M⊕ and a density of 1.01 ± 0.29 g cm^(-3). Hence, despite planet c having a radius almost twice as large as planet b, their masses are consistent with one another. Conclusions. We conclude that HD 106315c has a thick hydrogen-helium gaseous envelope. A detailed investigation of HD 106315b using a planetary interior model constrains the core mass fraction to be 5–29%, and the water mass fraction to be 10–50%. An alternative, not considered by our model, is that HD 106315b is composed of a large rocky core with a thick H–He envelope. Transmission spectroscopy of these planets will give insight into their atmospheric compositions and also help constrain their core compositions.
Additional Information
© 2017 ESO. Article published by EDP Sciences. Received 29 May 2017; Accepted 9 August 2017; Published online 01 December 2017. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 198.C-0168. We are grateful to the pool of HARPS observers who conducted part of the visitor-mode observations at La Silla Observatory: Romina Ibanez Bustos, Nicola Astudillo, Aurélien Wyttenbach, Esther Linder, Xavier Bonfils, Elodie Hébrard, and Alejandro Suarez. This work makes use of observations from the LCO network. This publication makes use of The Data & Analysis Center for Exoplanets (DACE), which is a facility based at the University of Geneva (CH) dedicated to extrasolar planets' data visualisation, exchange, and analysis. DACE is a platform of the Swiss National Centre of Competence in Research (NCCR) PlanetS, federating the Swiss expertise in Exoplanet research. The DACE platform is available at https://dace.unige.ch. This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This research has made use of the VizieR catalogue access tool, CDS, Strasbourg, France. The original description of the VizieR service was published in A&AS, 143, 23. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. The IA/Porto team acknowledges support from Fundação para a Ciência e a Tecnologia (FCT) through national funds and by FEDER through COMPETE2020 by these grants UID/FIS/04434/2013 & POCI-01-0145-FEDER-007672, PTDC/FIS-AST/1526/2014 & POCI-01-0145-FEDER-016886 and PTDC/FIS-AST/7073/2014 & POCI-01-0145-FEDER-016880. S.C.C.B., E.D.M. V.Zh.A., N.C.S., P.F., and S.G.S. also acknowledge support from FCT through Investigador FCT contracts IF/01312/2014/CP1215/CT000, IF/00849/2015, IF/00650/2015/CP1273/CT0001, IF/00169/2012/CP0150/CT0002, IF/01037/ 2013/CP1191/CT0001 and IF/00028/2014/CP1215/CT0002 funded by FCT (Portugal) and POPH/FSE (EC). V.Zh.A. and J.P.F. also acknowledge support from the FCT in the form of the grants SFRH/BPD/70574/2010 and SFRH/BD/93848/2013, respectively. P.F. further acknowledges support from Fundação para a Ciência e a Tecnologia (FCT) through POPH/FSE (EC) by FEDER funding through the programme "Programa Operacional de Factores de Competitividade – COMPETE" and exploratory project of reference IF/01037/2013/CP1191/CT0001. J.P.F., S.H., and J.J.N. acknowledge support by the fellowships SFRH/BD/93848/2013, PD/BD/128119/2016, and PD/BD/52700/2014, funded by FCT (Portugal) and POPH/FSE (EC). The French group acknowledges financial support from the French Programme National de Planétologie (PNP, INSU). The Swiss group acknowledges financial support the National Centre for Competence in Research "PlanetS" supported by the Swiss National Science Foundation (SNSF). DJA is funded under STFC consolidated grant reference ST/P000495/1. This work has been partly carried out thanks to support funding from Excellence Initiative of Aix-Marseille University A*MIDEX, a French "Investissements d'Avenir" programme. ACC acknowledges support from STFC consolidated grant number ST/M001296/1. X.D. is grateful to the Society in Science. The Branco Weiss Fellowship for its financial support. Part of this research has been funded by the Spanish grant ESP2015-65712-C5-1-R. We thank the anonymous referee for the careful review of this manuscript that improved its quality.Attached Files
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Additional details
- Eprint ID
- 84001
- Resolver ID
- CaltechAUTHORS:20171221-082508739
- NASA/JPL/Caltech
- NSF
- UID/FIS/04434/2013
- Fundação para a Ciência e a Tecnologia (FCT)
- POCI-01-0145-FEDER-007672
- Fundação para a Ciência e a Tecnologia (FCT)
- PTDC/FIS-AST/1526/2014
- Fundação para a Ciência e a Tecnologia (FCT)
- POCI-01-0145-FEDER-016886
- Fundação para a Ciência e a Tecnologia (FCT)
- PTDC/FIS-AST/7073/2014
- Fundação para a Ciência e a Tecnologia (FCT)
- POCI-01-0145-FEDER-016880
- Fundação para a Ciência e a Tecnologia (FCT)
- IF/01312/2014/CP1215/CT000
- Fundação para a Ciência e a Tecnologia (FCT)
- IF/00849/2015
- Fundação para a Ciência e a Tecnologia (FCT)
- IF/00650/2015/CP1273/CT0001
- Fundação para a Ciência e a Tecnologia (FCT)
- IF/00169/2012/CP0150/CT0002
- Fundação para a Ciência e a Tecnologia (FCT)
- IF/01037/ 2013/CP1191/CT0001
- Fundação para a Ciência e a Tecnologia (FCT)
- IF/00028/2014/CP1215/CT0002
- Fundação para a Ciência e a Tecnologia (FCT)
- Programa Operacional Potencial Humano (POPH)
- European Social Fund
- SFRH/BPD/70574/2010
- Fundação para a Ciência e a Tecnologia (FCT)
- SFRH/BD/93848/2013
- Fundação para a Ciência e a Tecnologia (FCT)
- Fondo Europeo de Desarrollo Regional (FEDER)
- PD/BD/128119/2016
- Fundação para a Ciência e a Tecnologia (FCT)
- PD/BD/52700/2014
- Fundação para a Ciência e a Tecnologia (FCT)
- Programme National de Planetologie (PNP)
- Institut national des sciences de l'Univers (INSU)
- Swiss National Science Foundation (SNSF)
- ST/P000495/1
- Science and Technology Facilities Council (STFC)
- Aix-Marseille University
- ST/M001296/1
- Science and Technology Facilities Council (STFC)
- Society in Science
- Branco Weiss Fellowship
- ESP2015-65712-C5-1-R
- Ministerio de Ciencia e Innovación (MCINN)
- Created
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2017-12-21Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field