Search for giant planets in M67 V: a warm Jupiter orbiting the turn-off star S1429

Abstract

Planets orbiting members of open or globular clusters offer a great opportunity to study exoplanet populations systematically as stars within clusters provide a mostly homogeneous sample at least in chemical composition and stellar age. However, even though there have been coordinated efforts to search for exoplanets in stellar clusters, only a small number of planets has been detected. One successful example is the seven-year radial velocity (RV) survey "Search for giant planets in M67" of 88 stars in the open cluster M67 which led to the discovery of five giant planets, including three close-in ($P<10$ days) hot-Jupiters. In this work, we continue and extend the observation of stars in M67 with the aim to search for additional planets. We conducted spectroscopic observations with the HPF, HARPS, HARPS-North, and SOPHIE spectrographs of 11 stars in M67. Six of our targets showed a variation or long-term trends in their RV during the original survey, while the other five were not observed in the original sample bringing the total number of stars to 93. An analysis of the radial velocities revealed one additional planet around the turn-off point star S1429 and gave solutions for the orbits of stellar companions around S2207 and YBP2018. S1429 b is a warm Jupiter on a likely circular orbit with a period of $77.48_{-0.19}^{+0.18}$ days and a minimum mass $\text{M}\sin i=1.80\pm 0.2$ M${}_{\text{J}}$. We update the hot-Jupiter occurrence rate in M67 to include the five new stars, deriving $4.2_{-2.3}^{+4.1}\%$ when considering all stars, and $5.4_{-3.0}^{+5.1}\%$ if binary star systems are removed.

27 pages, 20 figures. Accepted for publication in A&A

References in corpus (32)

• The K2 Mission: Characterization and Early results
• Bayes in the sky: Bayesian inference and model selection in cosmology
• APOGEE Data and Spectral Analysis from SDSS Data Release 16: Seven Years of Observations Including First Results from APOGEE-South
• Spectrum radial velocity analyser (SERVAL). High-precision radial velocities and two alternative spectral indicators
• Toward a Deterministic Model of Planetary Formation V. Accumulation Near the Ice Line
• Precise Radial Velocities of Giant Stars VII. Occurrence Rate of Giant Extrasolar Planets as a Function of Mass and Metallicity
• Planets around evolved intermediate-mass stars. I. Two substellar companions in the open clusters NGC 2423 and NGC 4349
• Hot Jupiters and Cool Stars
• Hot Jupiters from Coplanar High-eccentricity Migration
• Stellar Spectroscopy in the Near-infrared with a Laser Frequency Comb
• Four newborn planets transiting the young solar analog V1298 Tau
• The HETDEX Instrumentation: Hobby-Eberly Telescope Wide Field Upgrade and VIRUS
• Zodiacal Exoplanets in Time (ZEIT) IV: seven transiting planets in the Praesepe cluster
• Chemical Homogeneity in Collinder 261 and Implications for Chemical Tagging
• Ground-based CCD astrometry with wide field imagers. II. A star catalogue for M67: [email protected] MPG/ESO astrometry, FLAMES@VLT radial velocities
• Python Leap Second Management and Implementation of Precise Barycentric Correction (barycorrpy)
• ARIADNE: Measuring accurate and precise stellar parameters through SED fitting
• Hot Jupiters: Origins, Structure, Atmospheres
• On the Semimajor Axis Distribution of Extrasolar Gas Giant Planets: Why Hot Jupiters Are Rare Around High-Mass Stars
• K2 Discovers a Busy Bee: An Unusual Transiting Neptune Found in the Beehive Cluster
• A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) -- I. Search for exoplanets and variable stars in the field of 47 Tuc
• Giant planet occurrence within 0.2 AU of low-luminosity red giant branch stars with K2
• The eccentricity distribution of giant planets and their relation to super-Earths in the pebble accretion scenario
• Precise radial velocities of giant stars XVI. Planet occurrence rates from the combined analysis of the Lick, EXPRESS, and PPPS giant star surveys
• Hot Jupiters driven by high-eccentricity migration in globular clusters
• The CARMENES search for exoplanets around M dwarfs. Period search in H$\alpha$, Na I D, and Ca II IRT lines
• Doppler Constraints on Planetary Companions to Nearby Sun-like Stars: An Archival Radial Velocity Survey of Southern Targets for Proposed NASA Direct Imaging Missions
• Hot Jupiter and ultra-cold Saturn formation in dense star clusters
• Hot Jupiter formation in dense clusters: secular chaos in multi-planetary systems
• Occurrence rate of hot Jupiters orbiting red giant stars
• Radial-velocity search and statistical studies for short-period planets in the Pleiades open cluster
• Making hot Jupiters in stellar clusters: the importance of binary exchange