The GAPS programme at TNG. XLVI. Deep search for low-mass planets in late-dwarf systems hosting cold Jupiters

Abstract

We present the results of a high-cadence and high-precision radial velocity (RV) monitoring of 3 late-type dwarf stars hosting long-period giants with well-measured orbits, in order to search for short-period sub-Neptunes (SN, $M\sin i<30$ M${}_{\oplus }$). Building on the results and expertise of our previous studies, we carry out combined fits of our HARPS-N data with literature RVs, using MCMC analyses and Gaussian Process regression. We then use the results of our survey to estimate the frequency of sub-Neptunes in systems hosting cold-Jupiters, $f(SN|CJ)$, and compare it with the frequency around field M-dwarfs, $f(SN)$. We identify a new short-period low-mass planet orbiting GJ 328, GJ 328\,c, with $P_c=241.8_{-1.7}^{+1.3}$ d and $M_c\sin i=21.4_{-3.2}^{+3.4}$ M${}_{\oplus }$. We moreover identify and model the chromospheric activity signals and rotation periods of GJ 649 and GJ 849, around which no additional planet is found. Then, taking into account also planetary system around the previosuly-analyzed low-mass star BD-11 4672, we derive an estimate of the frequencies of inner planets in such systems. In particular $f(SN|CJ)=0.25_{-0.07}^{+0.58}$ for mini-Neptunes ($10$ M${}_{\oplus }<M\sin i<30$ M${}_{\oplus }$, $P<150$ d), marginally larger than $f(SN)$. For lower-mass planets ($M\sin i<10$ M${}_{\oplus }$) instead $f(SN|CJ)<0.69$, compatible with $f(SN)$. In light of the newly detected mini-Neptune, we find tentative evidence of a positive correlation between the presence of those planets and that of inner low-mass planets, $f(SN|CJ)>f(SN)$. This might indicate that cold Jupiters have an opposite influence in the formation of inner sub-Neptunes around late-type dwarfs as opposed to their solar-type counterparts, boosting the formation of mini-Neptunes instead of impeding it.

arXiv comment21 pages, 17 figures, 8 table. Accepted by A&A

References in corpus (48)

• emcee: The MCMC Hammer
• Gaia Data Release 3: Summary of the content and survey properties
• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• Habitable Zones Around Main-Sequence Stars: New Estimates
• The Occurrence and Architecture of Exoplanetary Systems
• Planets and Stellar Activity: Hide and Seek in the CoRoT-7 system
• The Minimum-Mass Extrasolar Nebula: In-Situ Formation of Close-In Super-Earths
• The HARPS-TERRA project I. Description of the algorithms, performance and new measurements on a few remarkable stars observed by HARPS
• The ELODIE archive
• Formation of planetary systems by pebble accretion and migration: How the radial pebble flux determines a terrestrial-planet or super-Earth growth mode
• Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program I. Comparison of activity indices
• Magnetic Cycles and Rotation Periods of Late Type Stars from photometric time series
• TESS Discovery of a Transiting Super-Earth in the $\pi$ Mensae System
• Rotation periods of late-type dwarf stars from time-series high-resolution spectroscopy of chromospheric indicators
• They are Small Worlds After All: Revised Properties of Kepler M Dwarf Stars and their Planets
• An Excess of Jupiter Analogs in Super-Earth Systems
• The Super Earth-Cold Jupiter Relations
• Observable Consequences of Planet Formation Models in Systems with Close-in Terrestrial Planets
• Challenges in Planet Formation
• The CARMENES search for exoplanets around M dwarfs -- Planet occurrence rates from a subsample of 71 stars
• Hot super-Earths and giant planet cores from different migration histories
• SOPHIE+: First results of an octagonal-section fiber for high-precision radial velocity measurements
• The GAPS programme with HARPS-N at TNG. I: Observations of the Rossiter-McLaughlin effect and characterisation of the transiting system Qatar-1
• A Long-Period Jupiter-Mass Planet Orbiting the Nearby M Dwarf GJ849
• The HARPS search for southern extra-solar planets: XIV. Gl 176b, a super-Earth rather than a Neptune, and at a different period
• TESS's first planet: a super-Earth transiting the naked-eye star $\pi$ Mensae
• Synthesizing Exoplanet Demographics from Radial Velocity and Microlensing Surveys, II: The Frequency of Planets Orbiting M Dwarfs
• Cold Jupiters and improved masses in 38 Kepler and K2 small planet systems from 3661 HARPS-N radial velocities. No excess of cold Jupiters in small planet systems
• Gas giant planets as dynamical barriers to inward-migrating super-Earths
• CARMENES input catalogue of M dwarfs IV. New rotation periods from photometric time series
• Stacked Bayesian general Lomb-Scargle periodogram: Identifying stellar activity signals
• The CARMENES search for exoplanets around M dwarfs. Guaranteed time observations Data Release 1 (2016-2020)
• HADES RV Programme with HARPS-N at TNG. VII. Rotation and activity of M-Dwarfs from time-series high-resolution spectroscopy of chromospheric indicators
• The California Planet Survey IV: A Planet Orbiting the Giant Star HD 145934 and Updates to Seven Systems with Long-Period Planets
• Tests of In-Situ Formation Scenarios for Compact Multiplanet Systems
• The HADES RV Programme with HARPS-N@TNG - GJ 3998: An early M-dwarf hosting a system of Super-Earths
• The HADES RV Programme with HARPS-N@TNG II. Data treatment and simulations
• HADES RV Programme with HARPS-N at TNG XV. Planetary occurrence rates around early-M dwarfs
• The HADES RV Programme with HARPS-N@TNG. III. Flux-flux and activity-rotation relationships of early-M dwarfs
• Exploring the realm of scaled Solar System analogs with HARPS
• The GAPS Programme with HARPS-N@TNG II: No giant planets around the metal-poor star HIP 11952
• Secretly Eccentric: The Giant Planet and Activity Cycle of GJ 328
• The HADES RV Programme with HARPS-N@TNG VIII. Gl15A: A multiple wide planetary system sculpted by binary interaction
• HADES RV program with HARPS-N at TNG. IX. A super-Earth around the M dwarf Gl686
• TOI-969: a late-K dwarf with a hot mini-Neptune in the desert and an eccentric cold Jupiter
• The HADES RV Programme with HARPS-N at TNG XI. GJ 685 b: a warm super-Earth around an active M dwarf
• Stellar masks and bisector's shape for M-type stars observed in the GAPS Programme with HARPS-N at TNG
• The GAPS Programme at TNG -- XXIV. An eccentric Neptune-mass planet near the inner edge of the BD-11 4672 habitable zone

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