The HARPS search for southern extra-solar planets: XXXIX. HD 175607, the most metal-poor G dwarf with an orbiting sub-Neptune

A. Mortier; J. P. Faria; N. C. Santos; V. Rajpaul; P. Figueira; I. Boisse; A. Collier Cameron; X. Dumusque; G. Lo Curto; C. Lovis; M. Mayor; C. Melo; F. Pepe; D. Queloz; A. Santerne; D. Ségransan; S. G. Sousa; A. Sozzetti; S. Udry

doi:10.1051/0004-6361/201526905

The HARPS search for southern extra-solar planets: XXXIX. HD 175607, the most metal-poor G dwarf with an orbiting sub-Neptune

A. Mortier, J. P. Faria, N. C. Santos, V. Rajpaul, P. Figueira, I. Boisse, A. Collier Cameron, X. Dumusque, G. Lo Curto, C. Lovis, M. Mayor, C. Melo, F. Pepe, D. Queloz, A. Santerne, D. Ségransan, S. G. Sousa, A. Sozzetti, S. Udry

Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

22 Citations (Scopus)

Abstract

Context. The presence of a small-mass planet (M_p < 0.1 M_Jup) seems, to date, not to depend on metallicity, however, theoretical simulations have shown that stars with subsolar metallicities may be favoured for harbouring smaller planets. A large, dedicated survey of metal-poor stars with the HARPS spectrograph has thus been carried out to search for Neptunes and super-Earths. Aims. In this paper, we present the analysis of HD 175607, an old G6 star with metallicity [Fe/H] =-0.62. We gathered 119 radial velocity measurements in 110 nights over a time span of more than nine years. Methods. The radial velocities were analysed using Lomb-Scargle periodograms, a genetic algorithm, a Markov chain Monte Carlo analysis, and a Gaussian processes analysis. The spectra were also used to derive stellar properties. Several activity indicators were analysed to study the effect of stellar activity on the radial velocities. Results. We find evidence for the presence of a small Neptune-mass planet (M_psini = 8.98 ± 1.10 M) orbiting this star with an orbital period P = 29.01 ± 0.02 days in a slightly eccentric orbit (e = 0.11 ± 0.08). The period of this Neptune is close to the estimated rotational period of the star. However, from a detailed analysis of the radial velocities together with the stellar activity, we conclude that the best explanation of the signal is indeed the presence of a planetary companion rather than stellar related. An additional longer period signal (P ∼ 1400 d) is present in the data, for which more measurements are needed to constrain its nature and its properties. Conclusions. HD 175607 is the most metal-poor FGK dwarf with a detected low-mass planet amongst the currently known planet hosts. This discovery may thus have important consequences for planet formation and evolution theories.

Original language	English
Article number	A135
Journal	Astronomy and Astrophysics
Volume	585
DOIs	https://doi.org/10.1051/0004-6361/201526905
Publication status	Published - 1 Jan 2016

Bibliographical note

Funding Information:
This work made use of the Simbad Database. The research leading to these results received funding from the European Union Seventh Framework Programme (FP7/20072013) under grant agreement number 313014 (ETAEARTH). JPF acknowledges support from FCT through grant reference SFRH/BD/93848/2013. This work was supported by Fundação para a Ciência e a Tecnologia (FCT) through the research grant UID/FIS/04434/2013. P.F., N.C.S., and S.G.S. also acknowledge the support from FCT through Investigador FCT contracts of reference IF/01037/2013, IF/00169/2012, and IF/00028/2014, respectively, and POPH/FSE (EC) by FEDER funding through the programme “Programa Operacional de Factores de Competitividade COMPETE”. This work results within the collaboration of the COST Action TD 1308. A.S. is supported by the European Union under a Marie Curie Intra-European Fellowship for Career Development with reference FP7-PEOPLE-2013-IEF, number 627202.

Funding Information:
This work made use of the Simbad Database. The research leading to these results received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement number 313014 (ETAEARTH). JPF acknowledges support from FCT through grant reference SFRH/BD/93848/2013. This work was supported by Fundação para a Ciência e a Tecnologia (FCT) through the research grant UID/FIS/04434/2013. P.F., N.C.S., and S.G.S. also acknowledge the support from FCT through Investigador FCT contracts of reference IF/01037/2013, IF/00169/2012, and IF/00028/2014, respectively, and POPH/FSE (EC) by FEDER funding through the programme "Programa Operacional de Factores de Competitividade - COMPETE". This work results within the collaboration of the COST Action TD 1308. A.S. is supported by the European Union under a Marie Curie Intra- European Fellowship for Career Development with reference FP7-PEOPLE- 2013-IEF, number 627202.

Publisher Copyright:
© ESO, 2016.

Keywords

Planetary systems
Stars: abundances
Stars: activity
Stars: individual: HD 175607
Stars: solar-type
Techniques: radial velocities

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.1051/0004-6361/201526905

Cite this

Mortier, A., Faria, J. P., Santos, N. C., Rajpaul, V., Figueira, P., Boisse, I., Collier Cameron, A., Dumusque, X., Lo Curto, G., Lovis, C., Mayor, M., Melo, C., Pepe, F., Queloz, D., Santerne, A., Ségransan, D., Sousa, S. G., Sozzetti, A., & Udry, S. (2016). The HARPS search for southern extra-solar planets: XXXIX. HD 175607, the most metal-poor G dwarf with an orbiting sub-Neptune. Astronomy and Astrophysics, 585, Article A135. https://doi.org/10.1051/0004-6361/201526905

@article{5f7f7e9208dd470caf304b6c06a2eb1f,

title = "The HARPS search for southern extra-solar planets: XXXIX. HD 175607, the most metal-poor G dwarf with an orbiting sub-Neptune",

abstract = "Context. The presence of a small-mass planet (Mp < 0.1 MJup) seems, to date, not to depend on metallicity, however, theoretical simulations have shown that stars with subsolar metallicities may be favoured for harbouring smaller planets. A large, dedicated survey of metal-poor stars with the HARPS spectrograph has thus been carried out to search for Neptunes and super-Earths. Aims. In this paper, we present the analysis of HD 175607, an old G6 star with metallicity [Fe/H] =-0.62. We gathered 119 radial velocity measurements in 110 nights over a time span of more than nine years. Methods. The radial velocities were analysed using Lomb-Scargle periodograms, a genetic algorithm, a Markov chain Monte Carlo analysis, and a Gaussian processes analysis. The spectra were also used to derive stellar properties. Several activity indicators were analysed to study the effect of stellar activity on the radial velocities. Results. We find evidence for the presence of a small Neptune-mass planet (Mpsini = 8.98 ± 1.10 M) orbiting this star with an orbital period P = 29.01 ± 0.02 days in a slightly eccentric orbit (e = 0.11 ± 0.08). The period of this Neptune is close to the estimated rotational period of the star. However, from a detailed analysis of the radial velocities together with the stellar activity, we conclude that the best explanation of the signal is indeed the presence of a planetary companion rather than stellar related. An additional longer period signal (P ∼ 1400 d) is present in the data, for which more measurements are needed to constrain its nature and its properties. Conclusions. HD 175607 is the most metal-poor FGK dwarf with a detected low-mass planet amongst the currently known planet hosts. This discovery may thus have important consequences for planet formation and evolution theories.",

keywords = "Planetary systems, Stars: abundances, Stars: activity, Stars: individual: HD 175607, Stars: solar-type, Techniques: radial velocities",

author = "A. Mortier and Faria, {J. P.} and Santos, {N. C.} and V. Rajpaul and P. Figueira and I. Boisse and {Collier Cameron}, A. and X. Dumusque and {Lo Curto}, G. and C. Lovis and M. Mayor and C. Melo and F. Pepe and D. Queloz and A. Santerne and D. S{\'e}gransan and Sousa, {S. G.} and A. Sozzetti and S. Udry",

note = "Funding Information: This work made use of the Simbad Database. The research leading to these results received funding from the European Union Seventh Framework Programme (FP7/20072013) under grant agreement number 313014 (ETAEARTH). JPF acknowledges support from FCT through grant reference SFRH/BD/93848/2013. This work was supported by Funda{\c c}{\~a}o para a Ci{\^e}ncia e a Tecnologia (FCT) through the research grant UID/FIS/04434/2013. P.F., N.C.S., and S.G.S. also acknowledge the support from FCT through Investigador FCT contracts of reference IF/01037/2013, IF/00169/2012, and IF/00028/2014, respectively, and POPH/FSE (EC) by FEDER funding through the programme “Programa Operacional de Factores de Competitividade COMPETE”. This work results within the collaboration of the COST Action TD 1308. A.S. is supported by the European Union under a Marie Curie Intra-European Fellowship for Career Development with reference FP7-PEOPLE-2013-IEF, number 627202. Funding Information: This work made use of the Simbad Database. The research leading to these results received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement number 313014 (ETAEARTH). JPF acknowledges support from FCT through grant reference SFRH/BD/93848/2013. This work was supported by Funda{\c c}{\~a}o para a Ci{\^e}ncia e a Tecnologia (FCT) through the research grant UID/FIS/04434/2013. P.F., N.C.S., and S.G.S. also acknowledge the support from FCT through Investigador FCT contracts of reference IF/01037/2013, IF/00169/2012, and IF/00028/2014, respectively, and POPH/FSE (EC) by FEDER funding through the programme {"}Programa Operacional de Factores de Competitividade - COMPETE{"}. This work results within the collaboration of the COST Action TD 1308. A.S. is supported by the European Union under a Marie Curie Intra- European Fellowship for Career Development with reference FP7-PEOPLE- 2013-IEF, number 627202. Publisher Copyright: {\textcopyright} ESO, 2016.",

year = "2016",

month = jan,

day = "1",

doi = "10.1051/0004-6361/201526905",

language = "English",

volume = "585",

journal = "Astronomy and Astrophysics",

issn = "0004-6361",

publisher = "EDP Sciences",

}

Mortier, A, Faria, JP, Santos, NC, Rajpaul, V, Figueira, P, Boisse, I, Collier Cameron, A, Dumusque, X, Lo Curto, G, Lovis, C, Mayor, M, Melo, C, Pepe, F, Queloz, D, Santerne, A, Ségransan, D, Sousa, SG, Sozzetti, A & Udry, S 2016, 'The HARPS search for southern extra-solar planets: XXXIX. HD 175607, the most metal-poor G dwarf with an orbiting sub-Neptune', Astronomy and Astrophysics, vol. 585, A135. https://doi.org/10.1051/0004-6361/201526905

TY - JOUR

T1 - The HARPS search for southern extra-solar planets

T2 - XXXIX. HD 175607, the most metal-poor G dwarf with an orbiting sub-Neptune

AU - Mortier, A.

AU - Faria, J. P.

AU - Santos, N. C.

AU - Rajpaul, V.

AU - Figueira, P.

AU - Boisse, I.

AU - Collier Cameron, A.

AU - Dumusque, X.

AU - Lo Curto, G.

AU - Lovis, C.

AU - Mayor, M.

AU - Melo, C.

AU - Pepe, F.

AU - Queloz, D.

AU - Santerne, A.

AU - Ségransan, D.

AU - Sousa, S. G.

AU - Sozzetti, A.

AU - Udry, S.

N1 - Funding Information: This work made use of the Simbad Database. The research leading to these results received funding from the European Union Seventh Framework Programme (FP7/20072013) under grant agreement number 313014 (ETAEARTH). JPF acknowledges support from FCT through grant reference SFRH/BD/93848/2013. This work was supported by Fundação para a Ciência e a Tecnologia (FCT) through the research grant UID/FIS/04434/2013. P.F., N.C.S., and S.G.S. also acknowledge the support from FCT through Investigador FCT contracts of reference IF/01037/2013, IF/00169/2012, and IF/00028/2014, respectively, and POPH/FSE (EC) by FEDER funding through the programme “Programa Operacional de Factores de Competitividade COMPETE”. This work results within the collaboration of the COST Action TD 1308. A.S. is supported by the European Union under a Marie Curie Intra-European Fellowship for Career Development with reference FP7-PEOPLE-2013-IEF, number 627202. Funding Information: This work made use of the Simbad Database. The research leading to these results received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement number 313014 (ETAEARTH). JPF acknowledges support from FCT through grant reference SFRH/BD/93848/2013. This work was supported by Fundação para a Ciência e a Tecnologia (FCT) through the research grant UID/FIS/04434/2013. P.F., N.C.S., and S.G.S. also acknowledge the support from FCT through Investigador FCT contracts of reference IF/01037/2013, IF/00169/2012, and IF/00028/2014, respectively, and POPH/FSE (EC) by FEDER funding through the programme "Programa Operacional de Factores de Competitividade - COMPETE". This work results within the collaboration of the COST Action TD 1308. A.S. is supported by the European Union under a Marie Curie Intra- European Fellowship for Career Development with reference FP7-PEOPLE- 2013-IEF, number 627202. Publisher Copyright: © ESO, 2016.

PY - 2016/1/1

Y1 - 2016/1/1

N2 - Context. The presence of a small-mass planet (Mp < 0.1 MJup) seems, to date, not to depend on metallicity, however, theoretical simulations have shown that stars with subsolar metallicities may be favoured for harbouring smaller planets. A large, dedicated survey of metal-poor stars with the HARPS spectrograph has thus been carried out to search for Neptunes and super-Earths. Aims. In this paper, we present the analysis of HD 175607, an old G6 star with metallicity [Fe/H] =-0.62. We gathered 119 radial velocity measurements in 110 nights over a time span of more than nine years. Methods. The radial velocities were analysed using Lomb-Scargle periodograms, a genetic algorithm, a Markov chain Monte Carlo analysis, and a Gaussian processes analysis. The spectra were also used to derive stellar properties. Several activity indicators were analysed to study the effect of stellar activity on the radial velocities. Results. We find evidence for the presence of a small Neptune-mass planet (Mpsini = 8.98 ± 1.10 M) orbiting this star with an orbital period P = 29.01 ± 0.02 days in a slightly eccentric orbit (e = 0.11 ± 0.08). The period of this Neptune is close to the estimated rotational period of the star. However, from a detailed analysis of the radial velocities together with the stellar activity, we conclude that the best explanation of the signal is indeed the presence of a planetary companion rather than stellar related. An additional longer period signal (P ∼ 1400 d) is present in the data, for which more measurements are needed to constrain its nature and its properties. Conclusions. HD 175607 is the most metal-poor FGK dwarf with a detected low-mass planet amongst the currently known planet hosts. This discovery may thus have important consequences for planet formation and evolution theories.

AB - Context. The presence of a small-mass planet (Mp < 0.1 MJup) seems, to date, not to depend on metallicity, however, theoretical simulations have shown that stars with subsolar metallicities may be favoured for harbouring smaller planets. A large, dedicated survey of metal-poor stars with the HARPS spectrograph has thus been carried out to search for Neptunes and super-Earths. Aims. In this paper, we present the analysis of HD 175607, an old G6 star with metallicity [Fe/H] =-0.62. We gathered 119 radial velocity measurements in 110 nights over a time span of more than nine years. Methods. The radial velocities were analysed using Lomb-Scargle periodograms, a genetic algorithm, a Markov chain Monte Carlo analysis, and a Gaussian processes analysis. The spectra were also used to derive stellar properties. Several activity indicators were analysed to study the effect of stellar activity on the radial velocities. Results. We find evidence for the presence of a small Neptune-mass planet (Mpsini = 8.98 ± 1.10 M) orbiting this star with an orbital period P = 29.01 ± 0.02 days in a slightly eccentric orbit (e = 0.11 ± 0.08). The period of this Neptune is close to the estimated rotational period of the star. However, from a detailed analysis of the radial velocities together with the stellar activity, we conclude that the best explanation of the signal is indeed the presence of a planetary companion rather than stellar related. An additional longer period signal (P ∼ 1400 d) is present in the data, for which more measurements are needed to constrain its nature and its properties. Conclusions. HD 175607 is the most metal-poor FGK dwarf with a detected low-mass planet amongst the currently known planet hosts. This discovery may thus have important consequences for planet formation and evolution theories.

KW - Planetary systems

KW - Stars: abundances

KW - Stars: activity

KW - Stars: individual: HD 175607

KW - Stars: solar-type

KW - Techniques: radial velocities

UR - http://www.scopus.com/inward/record.url?scp=84954271077&partnerID=8YFLogxK

U2 - 10.1051/0004-6361/201526905

DO - 10.1051/0004-6361/201526905

M3 - Article

AN - SCOPUS:84954271077

SN - 0004-6361

VL - 585

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

M1 - A135

ER -

The HARPS search for southern extra-solar planets: XXXIX. HD 175607, the most metal-poor G dwarf with an orbiting sub-Neptune

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

Fingerprint

Cite this