Validation of HD 183579b using archival radial velocities: a warm-neptune orbiting a bright solar analog

Abstract

As exoplanetary science matures into its third decade, we are increasingly offered the possibility of pre existing, archival observations for newly detected candidates. This is particularly poignant for the TESS mission, whose survey spans bright, nearby dwarf stars in both hemispheres, which are precisely the types of sources targeted by previous radial velocity (RV) surveys. On this basis, we investigated whether any of the TESS Objects of Interest (TOIs) coincided with such observations, from which we find 18 single planet candidate systems. Of these, one exhibits an RV signature that has the correct period and phase matching the transiting planetary candidate with a false alarm probability of less than 1 percent. After further checks, we exploit this fact to validate HD 183579b (TOI-1055b). This planet is less than 4 Earth Radii and has better than 33 percent planetary mass measurements, thus advancing the TESS primary objective of finding 50 such worlds. We find that this planet is amongst the most accessible small transiting planets for atmospheric characterization. Our work highlights that the efforts to confirm and even precisely measure the masses of new transiting planet candidates need not always depend on acquiring new observations - that in some instances these tasks can be completed with existing data.

13 pages, 4 figures, accepted to ApJL, posteriors available at https://github.com/skypalat/toi_validation

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Cited by in corpus (6)

• Resonant sub-Neptunes are puffier
• TOI-1055 b: Neptunian planet characterised with HARPS, TESS, and CHEOPS
• HD 183579b: A Warm Sub-Neptune Transiting a Solar Twin Detected by TESS
• NIGHT: a compact, near-infrared, high-resolution spectrograph to survey helium in exoplanet systems
• The Magnetically Induced Radial Velocity Variation of Gliese 341 and an Upper Limit to the Mass of Its Transiting Earth-sized Planet
• The Occurrence-weighted Median Planets Discovered by Transit Surveys Orbiting Solar-type Stars and Their Implications for Planet Formation and Evolution