A HARPS radial velocity search for planets in the Scorpius-Centaurus association. And its combination with the HARPS and SOPHIE young nearby stars (YNS) surveys

Abstract

The Scorpius-Centaurus (Sco-Cen) young and nearby massive star-forming region is particularly well suited for extrasolar planet searches with both direct imaging and radial velocity (RV) techniques. The RV search, however, is challenging, as the stars are faster rotators on average than their older stellar counterparts of similar spectral types. Moreover, the RV time series show strong signatures of stellar variability (spots and faculae) and/or stellar pulsations. Our aim is to search for giant planets (GPs) and brown dwarfs at short orbital distances around star members of the Sco-Cen association. We also aim at using these data together with others available on young stars to estimate the GP occurrence rate for young stars for periods of up to 1000 days. We used the HARPS spectrograph on the 3.6m telescope at the La Silla Observatory to monitor 88 A-F Sco-Cen stars. To improve our statistics and analysis, we combined this survey with two previous surveys that focused on young nearby stars (YNS) to compute companion occurrence rates from a sample of 176 young A-M stars. We report the discovery of a massive hot-Jupiter candidate around HD 145467, together with the discovery of one probable short-period (P < 10 days) brown dwarf around HD 149790. In addition, we confirm the binary nature of eight single-line binaries: HD 108857, HD 108904, HD 111102, HD 114319, HD 121176, HD 126488, HD 126838, and HD 133574. From our sample, we obtain a GP ($m_c\in [1;13]M_{Jup}$) occurrence rate of $0.7_{-0.2}^{+1.6}\%$ for periods between 1 and 1000 days and a brown dwarf ($m_c\in [13;80]M_{Jup}$) occurrence rate of $0.6_{-0.2}^{+1.4}\%$, in the same period range. In addition, we report a possible lack of close ($P\in [1;1000]days$) GPs around young F-K stars compared to their older counterparts, with a confidence level of 95%.

40 pages, 28 Figures, 7 Tables

References in corpus (31)

• Basic physical parameters of a selected sample of evolved stars
• The Gemini Planet Imager Exoplanet Survey: Giant Planet and Brown Dwarf Demographics From 10-100 AU
• Two accreting protoplanets around the young star PDS 70
• TW Hydrae: evidence of stellar spots instead of a Hot Jupiter
• Direct Imaging and Spectroscopy of a Planetary Mass Candidate Companion to a Young Solar Analog
• Improved angular momentum evolution model for solar-like stars II. Exploring the mass dependence
• Search for exoplanets with the radial-velocity technique: quantitative diagnostics of stellar activity
• Discovery of a warm, dusty giant planet around HIP65426
• Four newborn planets transiting the young solar analog V1298 Tau
• Extrasolar planets and brown dwarfs around A-F type stars VI. High precision RV survey of early type dwarfs with HARPS
• Debris Disks in the Scorpius-Centaurus OB Association Resolved by ALMA
• TESS Hunt for Young and Maturing Exoplanets (THYME) II: A 17 Myr Old Transiting Hot Jupiter in the Sco-Cen Association
• Multi-order TODCOR: application to observations taken with the CORALIE echelle spectrograph
• The VLT/NaCo Large program to probe the occurrence of exoplanets and brown dwarfs in wide orbits: I- Sample definition and characterization
• Differential Radial Velocities and Stellar Parameters of Nearby Young Stars
• A new Neptune-mass planet orbiting HD 219828
• Two Directly Imaged, Wide-orbit Giant Planets around the Young, Solar Analog TYC 8998-760-1
• Formation of Hot Jupiters through Secular Chaos and Dynamical Tides
• The SPHERE infrared survey for exoplanets (SHINE)- I Sample definition and target characterization
• The magnetic field and accretion regime of CI Tau
• Discovery of Seven Companions to Intermediate Mass Stars with Extreme Mass Ratios in the Scorpius-Centaurus Association
• The Young Suns Exoplanet Survey: Detection of a wide orbit planetary mass companion to a solar-type Sco-Cen member
• Discovery of a directly imaged planet to the young solar analog YSES 2
• Extrasolar planets and brown dwarfs around AF-type stars. IX. The HARPS southern sample
• Belt(s) of debris resolved around the Sco-Cen star HIP 67497
• A HARPS RV search for planets around young nearby stars
• Exploring the Brown Dwarf Desert: New Substellar Companions from the SDSS-III MARVELS Survey
• The First Scattered Light Image of the Debris Disk around the Sco-Cen target HD 129590
• Masses of the components of SB2 binaries observed with Gaia. IV. Accurate SB2 orbits for 14 binaries, and masses of 3 binaries
• New binaries from the SHINE survey
• Masses of the components of SB2 binaries observed with Gaia. V. Accurate SB2 orbits for 10 binaries and masses of the components of 5 binaries

Cited by in corpus (8)

• The PLATO field selection process. II. Characterization of LOPS2, the first long-pointing field
• Joint Modeling of Radial Velocities and Photometry with a Gaussian Process Framework
• Planets around evolved intermediate-mass stars III. Planet candidates and long-term activity signals in six open clusters
• Characterization of debris disks observed with SPHERE
• Imaging the positron annihilation line with 20 years of INTEGRAL/SPI observations
• GPI+SPHERE detection of a 6.1 $M_{\text{Jup}}$ circumbinary planet around HD 143811
• HD 143811 AB b: A Directly Imaged Planet Orbiting a Spectroscopic Binary in Sco-Cen
• The first scattered light images of HD 112810, a faint debris disk in the Sco-Cen association