HD 20329b: An ultra-short-period planet around a solar-type star found by TESS

Abstract

We used TESS light curves and HARPS-N spectrograph radial velocity measurements to establish the physical properties of the transiting exoplanet candidate found around the star HD 20329 (TOI-4524). We performed a joint fit of the light curves and radial velocity time series to measure the mass, radius, and orbital parameters of the candidate. We confirm and characterize HD 20329b, an ultra-short-period (USP) planet transiting a solar-type star. The host star (HD 20329, $V=8.74$ mag, $J=7.5$ mag) is characterized by its G5 spectral type with ${\mathrm{M}}_{\star }=0.90\pm 0.05$ M${}_{\odot }$, ${\mathrm{R}}_{\star }=1.13\pm 0.02$ R${}_{\odot }$, and ${\mathrm{T}}_{\mathrm{eff}}=5596\pm 50$ K; it is located at a distance $d=63.68\pm 0.29$ pc. By jointly fitting the available TESS transit light curves and follow-up radial velocity measurements, we find an orbital period of $0.9261\pm (0.5\times 10^{-4})$ days, a planetary radius of $1.72\pm 0.07$ ${\mathrm{R}}_{\oplus }$, and a mass of $7.42\pm 1.09$ ${\mathrm{M}}_{\oplus }$, implying a mean density of ${\rho }_{\mathrm{p}}=8.06\pm 1.53$ g cm${}^{-3}$. HD 20329b joins the $\sim$30 currently known USP planets with radius and Doppler mass measurements.

Accepted for publication in A&A, 26 pages

References in corpus (29)

• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• The James Webb Space Telescope
• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• The K2 Mission: Characterization and Early results
• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• Gaia Early Data Release 3: The astrometric solution
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• Growth Model Interpretation of Planet Size Distribution
• KEPLER's First Rocky Planet: Kepler-10b
• Spectrum radial velocity analyser (SERVAL). High-precision radial velocities and two alternative spectral indicators
• Radial velocity planets de-aliased. A new, short period for Super-Earth 55 Cnc e
• The Hipparcos-Gaia Catalog of Accelerations: Gaia EDR3 Edition
• Stellar Abundances in the Solar Neighborhood: The Hypatia Catalog
• The Kepler Follow-Up Observation Program. I. A Catalog of Companions to Kepler Stars from High-Resolution Imaging
• A Study of the Shortest-Period Planets Found With Kepler
• Transit Least Squares: Optimized transit detection algorithm to search for periodic transits of small planets
• PyTransit: Fast and Easy Exoplanet Transit Modelling in Python
• A Guide to Realistic Uncertainties on Fundamental Properties of Solar-Type Exoplanet Host Stars
• Atomic data for the Gaia-ESO Survey
• Transiting extrasolar planetary candidates in the Galactic bulge
• GJ 367b: A dense ultra-short period sub-Earth planet transiting a nearby red dwarf star
• Formation of Ultra-Short-Period Planets by Obliquity-Driven Tidal Runaway
• Gaia Search for stellar Companions of TESS Objects of Interest
• A study of the performance of the transit detection tool DST in space-based surveys. Application of the CoRoT pipeline to Kepler data
• TOI-674b: an oasis in the desert of exo-Neptunes transiting a nearby M dwarf
• Gaia Search for stellar Companions of TESS Objects of Interest II
• The HD 260655 system: Two rocky worlds transiting a bright M dwarf at 10 pc
• TOI-519 b: a short-period substellar object around an M dwarf validated using multicolour photometry and phase curve analysis
• A low-eccentricity migration pathway for a 13-h-period Earth analogue in a four-planet system

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