J/other/Nat/586.528 Properties of exoplanet host stars (Winter+, 2020)
Stellar clustering shapes the architecture of planetary systems.
Winter A.J., Kruijssen J.M.D., Longmore S.N., Chevance M.
<Nature, 586, 528-532 (2020)>
=2020Natur.586..528W 2020Natur.586..528W (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Stars, masses ;
Stars, ages
Abstract:
Planet formation is generally described in terms of a system
containing the host star and a protoplanetary disk, of which the
internal properties (for example, mass and metallicity) determine the
properties of the resulting planetary system. However,
(proto)planetary systems are predicted and observed to be affected by
the spatially clustered stellar formation environment, through either
dynamical star-star interactions or external photoevaporation by
nearby massive stars. It is challenging to quantify how the
architecture of planetary sysems is affected by these environmental
processes, because stellar groups spatially disperse within less than
a billion years, well below the ages of most known exoplanets. Here we
identify old, co-moving stellar groups around exoplanet host stars in
the astrometric data from the Gaia satellite and demonstrate that the
architecture of planetary systems exhibits a strong dependence on
local stellar clustering in position-velocity phase space. After
controlling for host stellar age, mass, metallicity and distance from
the star, we obtain highly significant differences (with p values of
10-5 to 10-2) in planetary system properties between phase space
overdensities (composed of a greater number of co-moving stars than
unstructured space) and the field. The median semi-major axis and
orbital period of planets in phase space overdensities are 0.087
astronomical units and 9.6 days, respectively, compared to 0.81
astronomical units and 154 days, respectively, for planets around
field stars. 'Hot Jupiters' (massive, short-period exoplanets)
predominantly exist in stellar phase space overdensities, strongly
suggesting that their extreme orbits originate from environmental
perturbations rather than internal migration or planet-planet
scattering. Our findings reveal that stellar clustering is a key
factor setting the architectures of planetary systems.
Description:
Properties of exoplanet host stars with six-dimensional astrometric
data from Gaia DR2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 87 1140 Properties of exoplanet host stars with
six-dimensional astrometric data from Gaia DR2
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Host Exoplanet host star
24- 28 F5.2 Msun M* ? Stellar mass (1)
30- 34 F5.2 Msun e_M* ? Stellar mass error (1)
36- 40 F5.2 Gyr Tage ? Age (1)
42- 45 F4.2 Gyr e_Tage ? Age error (1)
48- 50 I3 --- S Number of neighbouring stars within 40pc used
to construct the relative phase space
density distribution
53- 58 F6.2 [-] logPnull Probability the local phase space densities
are consistent with a single lognormal
distribution
61- 66 F6.2 --- BIC1-2 Difference between the Bayesian information
criterion (BIC) of the one-component
lognormal fit to the phase space density
distribution and the two-component fit
69- 73 F5.2 [-] logbetaM20 Relative phase space density
75- 81 F7.2 [-] logPhigh Probability that the star occupies a phase
space overdensity
84 A1 --- HJ? [Y/N] whether the star is orbited by a
hot Jupiter
87 A1 --- Include? [Y/N] whether it is included in the final
sample after applying our selection cuts
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Note (1): as retrieved from the composite table of the NASA Exoplanet Archive.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 17-Nov-2020