Asteroseismic masses of retired planet-hosting A-stars using SONG

Stello, D.; Huber, Daniel; Grundahl, Frank; Lloyd, James; Ireland, Mike; Casagrande, Luca; Fredslund, Mads; Bedding, Timothy R.; Palle, P. L.; Antoci, Victoria; Kjeldsen, Hans; Christensen-Dalsgaard, Jørgen
Bibliographical reference

Monthly Notices of the Royal Astronomical Society, Volume 472, Issue 4, p.4110-4116

Advertised on:
12
2017
Number of authors
12
IAC number of authors
1
Citations
28
Refereed citations
27
Description
To better understand how planets form, it is important to study planet occurrence rates as a function of stellar mass. However, estimating masses of field stars is often difficult. Over the past decade, a controversy has arisen about the inferred occurrence rate of gas-giant planets around evolved intermediate-mass stars - the so-called `retired A-stars'. The high masses of these red-giant planet hosts, derived using spectroscopic information and stellar evolution models, have been called into question. Here, we address the controversy by determining the masses of eight evolved planet-hosting stars using asteroseismology. We compare the masses with spectroscopic-based masses from the Exoplanet Orbit Database,which were previously adopted to infer properties of the exoplanets and their hosts. We find a significant one-sided offset between the two sets of masses for stars with spectroscopic masses above roughly 1.6 M⊙, suggestive of an average 15-20 per cent overestimate of the adopted spectroscopic-based masses. The only star in our sample well below this mass limit is also the only one not showing this offset. Finally, we note that the scatter across literature values of spectroscopic-based masses often exceeds their formal uncertainties, making it comparable to the offset we report here.
Related projects
Helio and Asteroseismology
Helio and Astero-Seismology and Exoplanets Search
The principal objectives of this project are: 1) to study the structure and dynamics of the solar interior, 2) to extend this study to other stars, 3) to search for extrasolar planets using photometric methods (primarily by transits of their host stars) and their characterization (using radial velocity information) and 4) the study of the planetary
Savita
Mathur