Chromospheric activities and kinematics for solar type dwarfs and subgiants: analysis of the activity distribution and the AVR

Jenkins, James S.; Murgas, F.; Rojo, P.; Jones, H. R. A.; Day-Jones, A. C.; Jones, M. I.; Clarke, J. R. A.; Ruíz, M. T.; Pinfield, D. J.

doi:10.1051/0004-6361/201016333

Cited by 111 publications

(112 citation statements)

References 53 publications

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“…This result shows that no mechanism causing line asymmetries seems to be responsible for the observed RV signal. In addition, we computed stellar chromospheric activity, as described in Jenkins et al (2008Jenkins et al ( , 2011. The results are plotted in Fig.…”

Section: Line Profile Analysis and Stellar Photometric Variabilitymentioning

confidence: 99%

The properties of planets around giant stars

Jones

Jenkins

Bluhm

et al. 2014

A&A

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Context. More than 50 exoplanets have been found around giant stars, revealing different properties when compared to planets orbiting solar-type stars. In particular, they are super-Jupiters and are not found orbiting interior to ∼0.5 AU. Aims. We are conducting a radial velocity study of a sample of 166 giant stars aimed at studying the population of close-in planets orbiting giant stars and how their orbital and physical properties are influenced by the post-MS evolution of the host star. Methods. We have collected multiepoch spectra for all of the targets in our sample. We have computed precision radial velocities from FECH/CHIRON and FEROS spectra, using the I 2 cell technique and the simultaneous calibration method, respectively. Results. We present the discovery of a massive planet around the giant star HIP 105854. The best Keplerian fit to the data leads to an orbital distance of 0.81 ± 0.03 AU, an eccentricity of 0.02 ± 0.03 and a projected mass of 8.2 ± 0.2 M J . With the addition of this new planet discovery, we performed a detailed analysis of the orbital properties and mass distribution of the planets orbiting giant stars. We show that there is an overabundance of planets around giant stars with a ∼ 0.5−0.9 AU, which might be attributed to tidal decay. Additionally, these planets are significantly more massive than those around MS and subgiant stars, suggesting that they grow via accretion either from the stellar wind or by mass transfer from the host star. Finally, we show that planets around evolved stars have lower orbital eccentricities than those orbiting solar-type stars, which suggests that they are either formed in different conditions or that their orbits are efficiently circularized by interactions with the host star.

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Section: Line Profile Analysis and Stellar Photometric Variabilitymentioning

confidence: 99%

The properties of planets around giant stars

Jones

Jenkins

Bluhm

et al. 2014

A&A

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“…Jenkins et al (2009) detected an eccentric planet (e = 0.17 ± 0.15) with a mass of 3.12 M Jup and a orbital period larger than 1000 days around HD 143361 (Houk 1978;Jenkins et al 2011). The planet-host star is a G6V star (Houk 1978) at 65.66 ± 5.51 pc from the Sun (van Leeuwen 2007) and a of 1.26 M Jup , low eccentricity (e ∼ 0.07), and a period of ∼1300 days.…”

Section: Appendix A: Potential Moving Group Membersmentioning

confidence: 99%

Binary frequency of planet-host stars at wide separations

Lodieu

Pérez‐Garrido

Béjar

et al. 2014

A&A

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Aims. The aim of the project is to improve our knowledge on the multiplicity of planet-host stars at wide physical separations. Methods. We cross-matched approximately 6200 square degree area of the southern sky imaged by the Visible Infrared Survey Telescope for Astronomy (VISTA) Hemisphere Survey (VHS) with the Two Micron All Sky Survey (2MASS) to look for wide common proper motion companions to known planet-host stars. We complemented our astrometric search with photometric criteria. Results. We confirmed spectroscopically the co-moving nature of seven sources out of 16 companion candidates and discarded eight, while the remaining one stays as a candidate. Among these new wide companions to planet-host stars, we discovered a T4.5 dwarf companion at 6.3 arcmin (∼9000 au) from HIP 70849, a K7V star which hosts a 9 Jupiter mass planet with an eccentric orbit. We also report two new stellar M dwarf companions to one G and one metal-rich K star. We infer stellar and substellar binary frequencies for our complete sample of 37 targets of 5.4 ± 3.8% and 2.7 ± 2.7% (1σ confidence level), respectively, for projected physical separations larger than ∼60-160 au assuming the range of distances of planet-host stars (24-75 pc). These values are comparable to the frequencies of non planet-host stars. We find that the period-eccentricity trend holds with a lack of multiple systems with planets at large eccentricities (e > 0.2) for periods less than 40 days. However, the lack of planets more massive than 2.5 Jupiter masses and short periods (<40 days) orbiting single stars is not so obvious due to recent discoveries by ground-based transit surveys and space missions.

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“…We performed three tests of our data to verify if this is the case for the stars we are studying. First, we measured the change in the flux from the Ca II HK lines over time by calculating the S-index for each epoch (the process is described in Jenkins et al 2008Jenkins et al , 2011. The second test we used was the bisector analysis (Toner & Gray 1988), aimed at detecting asymmetries in the line profiles caused by intrinsic stellar phenomena.…”

Section: S-index and Bisector Velocity Spanmentioning

confidence: 99%

RAFT – I. Discovery of new planetary candidates and updated orbits from archival FEROS spectra

Soto

Jenkins

Jones

2015

Monthly Notices of the Royal Astronomical Society

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A recent reanalysis of archival data has lead several authors to arrive at strikingly different conclusions for a number of planet-hosting candidate stars. In particular, some radial velocities measured using FEROS spectra have been shown to be inaccurate, throwing some doubt on the validity of a number of planet detections. Motivated by these results, we have begun the Reanalysis of Archival FEROS specTra (RAFT) program and here we discuss the first results from this work. We have reanalyzed FEROS data for the stars HD 11977, HD 47536, HD 70573, HD 110014 and HD 122430, all of which are claimed to have at least one planetary companion. We have reduced the raw data and computed the radial velocity variations of these stars, achieving a long-term precision of ∼ 10 m s −1 on the known stable star τ Ceti, and in good agreement with the residuals to our fits. We confirm the existence of planets around HD 11977, HD 47536 and HD 110014, but with different orbital parameters than those previously published. In addition, we found no evidence of the second planet candidate around HD 47536, nor any companions orbiting HD 122430 and HD 70573. Finally, we report the discovery of a second planet around HD 110014, with a minimum mass of 3.1 M Jup and a orbital period of 130 days. Analysis of activity indicators allow us to confirm the reality of our results and also to measure the impact of magnetic activity on our radial velocity measurements. These results confirm that very metal-poor stars down to [Fe/H]∼-0.7 dex, can indeed form giant planets given the right conditions.

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Chromospheric activities and kinematics for solar type dwarfs and subgiants: analysis of the activity distribution and the AVR

Cited by 111 publications

References 53 publications

The properties of planets around giant stars

The properties of planets around giant stars

Binary frequency of planet-host stars at wide separations

RAFT – I. Discovery of new planetary candidates and updated orbits from archival FEROS spectra

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