A Substellar Companion to the Intermediate‐Mass Giant 11 Comae

Liu, Yong-Jun; Sato, Bun’ei; Zhao, Gang; Noguchi, Kunio; Wang, H.; Kambe, Eiji; Ando, Hiroyasu; Izumiura, Hideyuki; Chen, Y.-Q.; Okada, Norio; Toyota, Eri; Omiya, Masashi; Masuda, Seiji; Takeda, Yoichi; Murata, Daisuke; Itoh, Yoichi; Yoshida, Michitoshi; Kokubo, Eiichiro; Ida, Shigeru

doi:10.1086/523297

Cited by 76 publications

(72 citation statements)

References 35 publications

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“…At the other end of the mass scale, the problems inherent to massive, early-type stars can be overcome by observing targets at a later stage of their evolution (Hatzes et al 2003;Setiawan et al 2005;Sato et al 2005;Reffert et al 2006;Johnson et al 2007b;Niedzielski et al 2007;Liu et al 2008;Döllinger et al 2009). Once stars exhaust their core hydrogen fuel sources, they move off of the main sequence, become cooler, and shed a large fraction of their primordial angular momentum (Gray & Nagar 1985;do Nascimento et al 2000).…”

Section: Introductionmentioning

confidence: 99%

Giant Planet Occurrence in the Stellar Mass-Metallicity Plane

Johnson¹,

Aller²,

Howard³

et al. 2010

PUBL ASTRON SOC PAC

767

824

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ABSTRACT. Correlations between stellar properties and the occurrence rate of exoplanets can be used to inform the target selection of future planet-search efforts and provide valuable clues about the planet-formation process. We analyze a sample of 1266 stars drawn from the California Planet Survey targets to determine the empirical functional form describing the likelihood of a star harboring a giant planet as a function of its mass and metallicity. Our stellar sample ranges from M dwarfs with masses as low as 0:2 M ⊙ to intermediate-mass subgiants with masses as high as 1:9 M ⊙ . In agreement with previous studies, our sample exhibits a planet-metallicity correlation at all stellar masses; the fraction of stars that harbor giant planets scales as f ∝ 10 1:2½Fe=H . We can rule out a flat metallicity relationship among our evolved stars (at 98% confidence), which argues that the high metallicities of stars with planets is not likely due to convective envelope "pollution." Our data also rule out a constant planet occurrence rate for ½Fe=H < 0, indicating that giant planets continue to become rarer at sub-Solar metallicities. We also find that planet occurrence increases with stellar mass (f ∝ M ⋆ ), characterized by a rise from 3% around M dwarfs (0:5 M ⊙ ) to 14% around A stars (2 M ⊙ ), at Solar metallicity. We argue that the correlation between stellar properties and giant planet occurrence is strong supporting evidence of the core-accretion model of planet formation.

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Section: Introductionmentioning

confidence: 99%

Giant Planet Occurrence in the Stellar Mass-Metallicity Plane

Johnson¹,

Aller²,

Howard³

et al. 2010

PUBL ASTRON SOC PAC

767

824

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“…For K-giant stars specifically, only four out of 72 known stars harboring planets are members of stellar multiple systems: 11 Com (Liu et al 2008), γ 1 Leo (Han et al 2010), 91 Aqr (Mitchell et al 2013), and 8 UMi (Lee et al 2015). Finding planets in multiple star systems allows us to learn more about the processes of planetary formation and evolution.…”

Section: Introductionmentioning

confidence: 99%

Precise radial velocities of giant stars

Ortiz

Reffert

Trifonov

et al. 2016

A&A

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Context. For over 12 yr, we have carried out a precise radial velocity (RV) survey of a sample of 373 G-and K-giant stars using the Hamilton Échelle Spectrograph at the Lick Observatory. There are, among others, a number of multiple planetary systems in our sample as well as several planetary candidates in stellar binaries. Aims. We aim at detecting and characterizing substellar and stellar companions to the giant star HD 59686 A (HR 2877, HIP 36616). Methods. We obtained high-precision RV measurements of the star HD 59686 A. By fitting a Keplerian model to the periodic changes in the RVs, we can assess the nature of companions in the system. To distinguish between RV variations that are due to non-radial pulsation or stellar spots, we used infrared RVs taken with the CRIRES spectrograph at the Very Large Telescope. Additionally, to characterize the system in more detail, we obtained high-resolution images with LMIRCam at the Large Binocular Telescope. Results. We report the probable discovery of a giant planet with a mass of m p sin i = 6.92 +0.18 −0.24 M Jup orbiting at a p = 1.0860 +0.0006 −0.0007 au from the giant star HD 59686 A. In addition to the planetary signal, we discovered an eccentric (e B = 0.729 +0.004 −0.003 ) binary companion with a mass of m B sin i = 0.5296 +0.0011 −0.0008 M orbiting at a close separation from the giant primary with a semi-major axis of a B = 13.56 +0.18 −0.14 au. Conclusions. The existence of the planet HD 59686 Ab in a tight eccentric binary system severely challenges standard giant planet formation theories and requires substantial improvements to such theories in tight binaries. Otherwise, alternative planet formation scenarios such as second-generation planets or dynamical interactions in an early phase of the system's lifetime need to be seriously considered to better understand the origin of this enigmatic planet.

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“…Therefore, G and K giant stars are suitable targets for detecting exoplanets with the RV technique. There are several ongoing exoplanet survey projects around giant stars (Setiawan et al 2005;Hatzes et al 2005;Sato et al 2007;Johnson et al 2007;Lovis & Mayor 2007;Niedzielski et al 2007;Liu et al 2008). Now, more Based on observations made with the BOES spectrograph at the 1.8 m telescope of BOAO, KASI RV data (Table 3) is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/509/A24 than 20 exoplanets have been detected around giant stars and from this sample some statistical studies on the planetary systems around giants have been made (Pasquini et al 2007;Hekker et al 2008;Sato et al 2008).…”

Section: Introductionmentioning

confidence: 99%

Detection of a planetary companion around the giant star γ¹Leonis

Han¹,

Lee

Kim³

et al. 2010

A&A

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Aims. Our primary goal is to search for planets around intermediate mass stars. We are also interested in studying the nature of radial velocity (RV) variations of K giant stars. Methods. We selected about 55 early K giant (K0−K4) stars brighter than fifth magnitude that were observed using BOES, a high resolution spectrograph attached to the 1.8 m telescope at BOAO (Bohyunsan Optical Astronomy Observatory). BOES is equipped with I 2 absorption cell for high precision RV measurements. Results. We detected a periodic radial velocity variations in the K0 III star γ 1 Leonis with a period of P = 429 days. An orbital fit of the observed RVs yields a period of P = 429 days, a semi-amplitude of K = 208 m s −1 , and an eccentricity of e = 0.14. To investigate the nature of the RV variations, we analyzed the photometric, Ca II λ 8662 equivalent width, and line-bisector variations of γ 1 Leonis . We conclude that the detected RV variations can be best explained by a planetary companion with an estimated mass of m sin i = 8.78 M Jupiter and a semi-major axis of a = 1.19 AU, assuming a stellar mass of 1.23 M .

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A Substellar Companion to the Intermediate‐Mass Giant 11 Comae

Cited by 76 publications

References 35 publications

Giant Planet Occurrence in the Stellar Mass-Metallicity Plane

Giant Planet Occurrence in the Stellar Mass-Metallicity Plane

Precise radial velocities of giant stars

Detection of a planetary companion around the giant star γ¹Leonis

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A Substellar Companion to the Intermediate‐Mass Giant 11 Comae

Cited by 76 publications

References 35 publications

Giant Planet Occurrence in the Stellar Mass-Metallicity Plane

Giant Planet Occurrence in the Stellar Mass-Metallicity Plane

Precise radial velocities of giant stars

Detection of a planetary companion around the giant star γ1Leonis

Contact Info

Product

Resources

About

Detection of a planetary companion around the giant star γ¹Leonis