TY - JOUR
T1 - Asteroseismic masses of retired planet-hosting A-stars using SONG
AU - Stello, Dennis
AU - Huber, Daniel
AU - Grundahl, Frank
AU - Lloyd, James
AU - Ireland, Mike
AU - Casagrande, Luca
AU - Fredslund, Mads
AU - Bedding, Timothy R.
AU - Palle, Pere L.
AU - Antoci, Victoria
AU - Kjeldsen, Hans
AU - Christensen-Dalsgaard, Jørgen
N1 - Publisher Copyright:
© 2017 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - 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 MO˙, 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.
AB - 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 MO˙, 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.
KW - Stars: fundamental parameters
KW - Stars: interiors
KW - Stars: oscillations
KW - Techniques: radial velocities
UR - http://www.scopus.com/inward/record.url?scp=85030721725&partnerID=8YFLogxK
U2 - 10.1093/mnras/stx2295
DO - 10.1093/mnras/stx2295
M3 - Article
SN - 0035-8711
VL - 472
SP - 4110
EP - 4116
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
M1 - stx2295
ER -