Researchers led by Wu Tao from the Yunnan Observatory of the Chinese Academy of Sciences and Jiang Chen from the Institute of Solar System Research. Max Planck reanalyzed the properties of the extremely eccentric planetary system HD 76920b through a detailed asteroseismic analysis of its parent star HD 76920.
The study was published on March 2, 2023 in The Astrophysical Journal.
HD 76920b is a gas giant exoplanet orbiting a K-type star. This planet has a mass of 3.93 Jupiter masses, takes 415.4 days to complete one revolution around its star, and is at a distance of 1.149 AU. from your star. Its opening was announced in 2017.
HD 76920b has an orbital eccentricity of 0.856 (comparable to Solar System bodies such as comet 2P/Encke and asteroid 3200 Phaeton), making it one of the most eccentric planets orbiting evolved stars.
Using astroseismic modeling performed by five separate international teams, the researchers improved measurements of stellar mass, radius and age, and updated the planet’s semi-major axis and mass.
With these updated characteristics of the planetary system, they confirmed that the planet is currently far enough away from the star to undergo tidal decay. And they predicted that the planet would be swallowed up by a stellar shell in about 100 million years.
Asteroseismology is best known for its ability to characterize key parameters of stars (eg mass, radius, density) with a high level of accuracy, which is a critical factor in limiting the properties of planets.
Source: Chen Jiang et al, TESS Asteroseismic Analysis of HD 76920: The Giant Star Hosting an Extremely Eccentric Exoplanet, The Astrophysical Journal (2023). DOI: 10.3847/1538-4357/acb8ac
