TESS asteroseismology of the known planet host star lambda(2) Fornacis


Nielsen M. B. , Ball W. H. , Standing M. R. , Triaud A. H. M. J. , Buzasi D., Carboneau L., ...More

ASTRONOMY & ASTROPHYSICS, vol.641, 2020 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 641
  • Publication Date: 2020
  • Doi Number: 10.1051/0004-6361/202037461
  • Title of Journal : ASTRONOMY & ASTROPHYSICS

Abstract

Context. The Transiting Exoplanet Survey Satellite (TESS) is observing bright known planet-host stars across almost the entire sky. These stars have been subject to extensive ground-based observations, providing a large number of radial velocity measurements.Aims. The objective of this work is to use the new TESS photometric observations to characterize the star lambda (2) Fornacis, and following this to update the parameters of the orbiting planet lambda (2) For b.Methods. We measured the frequencies of the p-mode oscillations in lambda (2) For, and in combination with non-seismic parameters estimated the stellar fundamental properties using stellar models. Using the revised stellar properties and a time series of archival radial velocities from the UCLES, HIRES and HARPS instruments spanning almost 20 years, we refit the orbit of lambda (2) For b and searched the residual radial velocities for remaining variability.Results. We find that lambda (2) For has a mass of 1.160.03 M-circle dot and a radius of 1.63 +/- 0.04 R-circle dot, with an age of 6.3 +/- 0.9 Gyr. This and the updated radial velocity measurements suggest a mass of lambda (2) For b of