A low-mass sub-Neptune planet transiting the bright active star HD 73344
arXiv:2405.17155 · doi:10.1051/0004-6361/202449559
Abstract
Context. Planets with radii of between 2-4 RE closely orbiting solar-type stars are of significant importance for studying the transition from rocky to giant planets. Aims. Our goal is to determine the mass of a transiting planet around the very bright F6 star HD 73344 . This star exhibits high activity and has a rotation period that is close to the orbital period of the planet. Methods. The transiting planet, initially a K2 candidate, is confirmed through TESS observations . We refined its parameters and rule out a false positive with Spitzer observations. We analyzed high-precision RV data from the SOPHIE and HIRES spectrographs. We conducted separate and joint analyses using the PASTIS software. We used a novel observing strategy, targeting the star at high cadence for two consecutive nights with SOPHIE to understand the short-term stellar variability. We modeled stellar noise with two Gaussian processes. Results. High-cadence RV observations provide better constraints on stellar variability and precise orbital parameters for the transiting planet. The derived mean density suggests a sub-Neptune-type composition, but uncertainties in the planet's mass prevent a detailed characterization. In addition, we find a periodic signal in the RV data that we attribute to the signature of a nontransiting exoplanet, without totally excluding the possibility of a nonplanetary origin. Dynamical analyses confirm the stability of the two-planet system and provide constraints on the inclination of the candidate planet; these findings favor a near-coplanar system. Conclusions. While the transiting planet orbits the bright star at a short period, stellar activity prevented us from precise mass measurements. Long-term RV tracking of this planet could improve this measurement, as well as our understanding of the activity of the host star.
Accepted for publication in Astronomy and Astrophysics
References in corpus (97)
- The Transiting Exoplanet Survey Satellite
- The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
- The James Webb Space Telescope
- The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
- The Dartmouth Stellar Evolution Database
- The K2 Mission: Characterization and Early results
- Accurate masses and radii of normal stars: modern results and applications
- Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
- No planet for HD 166435
- Understanding the Mass-Radius Relation for Sub-Neptunes: Radius as a Proxy for Composition
- The Occurrence and Mass Distribution of Close-in Super-Earths, Neptunes, and Jupiters
- Spectroscopic parameters for 451 stars in the HARPS GTO planet search program. Stellar [Fe/H] and the frequency of exo-Neptunes
- A Framework for Prioritizing the TESS Planetary Candidates Most Amenable to Atmospheric Characterization
- Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program.Galactic stellar populations and planets
- Planets and Stellar Activity: Hide and Seek in the CoRoT-7 system
- The California Planet Survey I. Four New Giant Exoplanets
- A Gaussian process framework for modelling stellar activity signals in radial velocity data
- Assessing statistical significance of periodogram peaks
- Spectral Properties of Cool Stars: Extended Abundance Analysis of 1617 Planet Search Stars
- Initial Characteristics of Kepler Long Cadence Data For Detecting Transiting Planets
- A new code for automatic determination of equivalent widths: Automatic Routine for line Equivalent widths in stellar Spectra (ARES)
- Stellar Spin-Orbit Misalignment in a Multiplanet System
- SWEET-Cat: A catalogue of parameters for Stars With ExoplanETs I. New atmospheric parameters and masses for 48 stars with planets
- A simple method to estimate radial velocity variations due to stellar activity using photometry
- Planetary detection limits taking into account stellar noise. I. Observational strategies to reduce stellar oscillation and granulation effects
- The connection between stellar granulation and oscillation as seen by the Kepler mission
- CoRoT reveals a magnetic activity cycle in a Sun-like star
- The orbital eccentricity of small planet systems
- Determining stellar macroturbulence using asteroseismic rotational velocities from Kepler
- EVEREST: Pixel Level Decorrelation of K2 Light curves
- Exoplanet Orbital Eccentricities Derived From LAMOST-Kepler Analysis
- Atmospheres of low-mass planets: the "boil-off"
- ARES v2 - new features and improved performance
- The cosmic shoreline: the evidence that escape determines which planets have atmospheres, and what this may mean for Proxima Centauri b
- Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program II: Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd and Eu
- PASTIS: Bayesian extrasolar planet validation. I. General framework, models, and performance
- A pair of planets around HD 202206 or a circumbinary planet?
- Transit and Eclipse Analyses of Exoplanet HD 149026b Using BLISS Mapping
- Magnetic activity of F stars observed by Kepler
- Evidence for the impact of stellar activity on the detectability of solar-like oscillations observed by Kepler
- Surface rotation and photometric activity for Kepler targets. II. G and F main-sequence stars, and cool subgiant stars
- Three years of Sun-as-a-star radial-velocity observations on the approach to solar minimum
- SOPHIE+: First results of an octagonal-section fiber for high-precision radial velocity measurements
- Surface rotation and photometric activity for Kepler targets I. M and K main-sequence stars
- AMD-stability and the classification of planetary systems
- A Model for Thermal Phase Variations of Circular and Eccentric Exoplanets
- Abundance to age ratios in the HARPS-GTO sample with Gaia DR2: Chemical clocks for a range of [Fe/H]
- Long-term planetary integration with individual time steps
- An update to the EVEREST K2 pipeline: Short cadence, saturated stars, and Kepler-like photometry down to Kp = 15
- Irradiated ocean planets bridge super-Earth and sub-Neptune populations
- Characterising stellar micro-variability for planetary transit searches
- Magnetic and Gravitational Disk-Star Interactions: An Interdependence of PMS Stellar Rotation Rates and Spin-Orbit Misalignments
- The SOPHIE search for northern extrasolar planets III. A Jupiter-mass companion around HD 109246
- Mass-radius relationships for irradiated ocean planets
- Aeronomical constraints to the minimum mass and maximum radius of hot low-mass planets
- SWEET-Cat 2.0: The Cat just got SWEETer; Higher quality spectra and precise parallaxes from GAIA eDR3
- Conclusive evidence for a population of water-worlds around M-dwarfs remains elusive
- Oxygen abundances in G- and F-type stars from HARPS
- New families of symplectic splitting methods for numerical integration in dynamical astronomy
- pyaneti II: A multidimensional Gaussian process approach to analysing spectroscopic time-series
- WASP-107b's density is even lower: a case study for the physics of planetary gas envelope accretion and orbital migration
- Filtering solar-like oscillations for exoplanet detection in radial velocity observations
- HD45364, a pair of planets in a 3:2 mean motion resonance
- WASP-8b: Characterization of a Cool and Eccentric Exoplanet with Spitzer
- Evolution of coexisting long and short period stellar activity cycles
- The SOPHIE search for northern extrasolar planets VIII. A warm Neptune orbiting HD164595
- Constraints on Super-Earths Interiors from Stellar Abundances
- Identifying the best iron-peak and -capture elements for chemical tagging: The impact of the number of lines on measured scatter
- Low False-Positive Rate of Kepler Candidates Estimated From A Combination Of Spitzer And Follow-Up Observations
- Dynamical stability analysis of the HD202206 system and constraints to the planetary orbits
- A 20-Second Cadence View of Solar-Type Stars and Their Planets with TESS: Asteroseismology of Solar Analogs and a Re-characterization of pi Men c
- Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program IV. Carbon and C/O ratios for Galactic stellar populations and planet hosts
- Revisiting the impact of stellar magnetic activity on the detectability of solar-like oscillations by Kepler
- An Overabundance of Low-density Neptune-like Planets
- HD60532, a planetary system in a 3:1 mean motion resonance
- High order symplectic integrators for planetary dynamics and their implementation in REBOUND
- Phase Curves of Hot Neptune LTT 9779b Suggest a High-Metallicity Atmosphere
- Planetary Candidates from K2 Campaign 16
- Stellar Characterization of Keck HIRES Spectra with The Cannon
- Oscillations of Relative Inclination Angles in Compact Extrasolar Planetary Systems
- TOI-3884 b: A rare 6-R planet that transits a low-mass star with a giant and likely polar spot
- Mitigating flicker noise in high-precision photometry. I -- Characterization of the noise structure, impact on the inferred transit parameters, and predictions for CHEOPS observations
- Stellar Oblateness versus Distant Giants in Exciting Kepler Planet Mutual Inclinations
- Magnetic activity evolution of solar-like stars: I. S_ph-Age relation derived from Kepler observations
- Connecting photometric and spectroscopic granulation signals with CHEOPS and ESPRESSO
- Long-term stellar activity variations and their effect on radial-velocity measurements
- Gaussian processes for radial velocity modeling Better rotation periods and planetary parameters with the quasi-periodic kernel and constrained priors
- The SOPHIE search for northern extrasolar planets-XIX. A system including a cold sub-Neptune potentially transiting a V = 6.5 star HD88986
- Water content trends in K2-138 and other low-mass multiplanetary systems
- A general stability-driven approach for the refinement of multi-planet systems
- Spitzer Infrared Observations and Independent Validation of the Transiting Super-Earth CoRoT-7b
- Analysis of the planetary mass uncertainties on the accuracy of atmospherical retrieval
- Activity time series of old stars from late F to early K VI. Exoplanet mass characterisation and detectability in radial velocity
- Correcting the effect of stellar spots on ARIEL transmission spectra
- Physical Properties and Impact Parameter Variations of Kepler Planets from Analytic Light Curve Modeling
- Detection of p-mode Oscillations in HD 35833 with NEID and TESS
- Semi-supervised standardized detection of extrasolar planets