J/MNRAS/490/5088 Stellar companions of exoplanet host stars (Mugrauer, 2019)
Search for stellar companions of exoplanet host stars by exploring the second
ESA-Gaia data release.
Mugrauer M.
<Mon. Not. R. Astron. Soc., 490, 5088-5102 (2019)>
=2019MNRAS.490.5088M 2019MNRAS.490.5088M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple
Keywords: techniques: high angular resolution - binaries: visual -
stars: imaging - stars: individual: HD8535B, HD118904B, HIP116454B,
Kepler-779B, WASP-98B - white dwarfs
Abstract:
A new survey is presented, which explores the second data release of
the ESA-Gaia mission, in order to search for stellar companions of
exoplanet host stars, located at distances closer than about 500pc
around the Sun. In total, 176 binaries, 27 hierarchical triples, and
one hierarchical quadruple system are detected among more than 1300
exoplanet host stars, whose multiplicity is investigated, yielding a
multiplicity rate of the exoplanet host stars of at least about 15 per
cent. The detected companions and the exoplanet host stars are
equidistant and share a common proper motion, as it is expected for
gravitationally bound stellar systems, proven with their accurate Gaia
astrometry. The companions exhibit masses in the range between about
0.078 and 1.4M☉ with a peak in their mass distribution between
0.15 and 0.3M☉_. The companions are separated from the exoplanet
host stars by about 20 up to 9100au, but are found most frequently
within a projected separation of 1000au. While most of the detected
companions are early M dwarfs, eight white dwarf companions of
exoplanet host stars are also identified in this survey, whose true
nature is revealed with their photometric properties. Hence, these
degenerated companions and the exoplanet host stars form evolved
stellar systems with exoplanets, which have survived (physically but
also dynamically) the post-main-sequence evolution of their former
primary star.
Description:
The astrometry and photometry of the exoplanet hosts stars and of
their stellar companions are summarized together with the derived
properties of the companions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 118 411 Astrometry and photometry of planet host stars
and companions
table3.dat 95 207 Relative astrometry of companions
table4.dat 74 207 Equatorial coordinates and properties of
companions
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Star Name
17 A1 --- n_Name [*] * for exoplanet host stars
19- 26 F8.4 mas Plx Gaia DR2 parallax
28- 33 F6.4 mas e_Plx Error of parallax
35- 43 F9.3 mas/yr pmRA Gaia DR2 proper motion in right ascension,
pmRA*cosDE
45- 49 F5.3 mas/yr e_pmRA Error of proper motion in right ascension
51- 59 F9.3 mas/yr pmDE Gaia DR2 proper motion in declination
61- 65 F5.3 mas/yr e_pmDE Error of proper motion in declination
67- 71 F5.3 mas epsi ? Gaia DR2 astrometric excess noise
73- 78 F6.1 --- sepsi ? Gaia DR2 significance of astrometric
excess noise
80- 86 F7.4 mag Gmag ? Gaia DR2 G-band mean magnitude
88- 93 F6.4 mag e_Gmag ? Error of Gaia DR2 G-band mean magnitude
95-100 F6.4 mag AG ? Gaia DR2 estimate of G-band extinction
102 A1 --- --- [-]
103-108 F6.4 mag e_AG ? Lower error of G-band extinction
110 A1 --- --- [+]
111-116 F6.4 mag E_AG ? Upper error of G-band extinction
118 A1 --- Note [x] x if AG is derived from AV
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Name of stellar companion (1)
17- 25 F9.5 arcsec rho Angular separation
27- 33 F7.5 arcsec e_rho Error of angular separation
35- 43 F9.5 deg PA Position angle
45- 51 F7.5 deg e_PA Error of position angle
53- 56 F4.2 mas Dplx Parallax difference
58- 61 F4.2 mas e_Dplx Error of parallax difference
63- 66 F4.1 --- sDplx Significance of parallax difference
68- 70 F3.1 --- sDplx-epsi ? Significance of parallax difference
including epsi
72- 76 F5.2 mas/yr mu-rel Differential proper motion (2)
78- 81 F4.2 mas/yr e_mu-rel Error of differential proper motion
83- 88 F6.1 --- smu-rel Significance of differential proper motion
91- 95 F5.1 --- CPM Common Proper Motion Index (3)
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Note (1): Companions which are eclipsing binaries are designated with (EB),
those which are spectroscopic binary stars with (SB).
Note (2): ifferential proper motion between the companion relative to the
exoplanet host star (murel=|muPH-mucomp|, with the proper motion of the
exoplanet host star muPH and of the companion muComp).
Note (3): the common proper motion index, which is defined as
CPM = |muPH+mucomp|/mu-rel, with the proper motion of the exoplanet host
star muPH and of the companion muComp.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Name of stellar companion
17- 31 F15.11 deg RAdeg Right Ascension (ICRS) at Ep=2015.5
33- 47 F15.11 deg DEdeg Declination (ICRS) at Ep=2015.5
49- 54 F6.3 mag GMAG Absolute magnitude in G-band
56- 59 I4 au Sep Projected separation to the exoplanet host star
61 A1 --- l_Mass [~] Limit flag on Mass
62- 66 F5.3 Msun Mass Mass
68- 71 I4 K Teff ? Effective temperature
73- 74 A2 --- Note [WD ] WD if companion is a white dwarf
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Acknowledgements:
Markus Mugrauer, markus(at)astro.uni-jena.de
(End) Patricia Vannier [CDS] 06-Oct-2020