J/MNRAS/421/2498 Stellar companions of exoplanet host stars (Ginski+, 2012)
A lucky imaging multiplicity study of exoplanet host stars.
Ginski C., Mugrauer M., Seeliger M., Eisenbeiss T.
<Mon. Not. R. Astron. Soc., 421, 2498-2509 (2012)>
=2012MNRAS.421.2498G 2012MNRAS.421.2498G
ADC_Keywords: Stars, double and multiple ; Planets
Keywords: techniques: high angular resolution - binaries: close -
stars: individual: HD 126614 - stars: individual: HD 185269
Abstract:
To understand the influence of additional wide stellar companions on
planet formation, it is necessary to determine the fraction of
multiple stellar systems amongst the known extrasolar planet
population.
We target recently discovered radial velocity exoplanetary systems
observable from the Northern hemisphere and with sufficiently high
proper motion to detect stellar companions via direct imaging. We
utilize the Calar Alto 2.2-m telescope in combination with its lucky
imaging camera AstraLux.
71 planet host stars have been observed so far, yielding one new
low-mass (0.239±0.022M☉) stellar companion, 4.5-arcsec (227 au
of projected separation) north-east of the planet host star HD 185269,
detected via astrometry with AstraLux. We also present follow-up
astrometry on three previously discovered stellar companions, showing
for the first time common proper motion of the 0.5-arcsec companion to
HD 126614. Additionally, we determined the achieved detection limits
for all targets, which allow us to characterize the detection space of
possible further companions of these stars.
Description:
Our sample consists of stars with RV planet candidates discovered
between 2008 and 2011. They are all observable from the Northern
hemisphere with declinations down to -22° and a relatively even
distribution in right ascension.
All observations were carried out with the Calar Alto 2.2-m telescope
in combination with the AstraLux instrument.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table6.dat 74 13 List of all stars with companions and companion
candidates detected
table7.dat 103 64 List of all stars with no additional stellar
components detected
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Table 5: Average absolute magnitudes and ages of all target stars in an
observation epoch.
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Epoch IMAG (mag) Age (Gyr)
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23/04/2008 4.32 4.9
11/07/2008 3.43 6.0
16/01/2009 2.93 4.6
07/09/2009 2.64 6.2
23/02/2010 3.72 2.2
14/07/2010 4.14 7.4
14/01/2011 3.67 5.4
27/07/2011 3.20 6.5
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Star Star name
11- 20 A10 "DD/MM/YYYY" ObsDate Epoch of observation
22- 26 I5 --- Nfr Number of frames (G1)
28- 32 F5.3 Msun M0.5 Minimum mass detectable at 0.5-arcsec (G2)
34- 38 F5.3 Msun e_M0.5 rms uncertainty on M0.5
40- 44 F5.3 Msun M1 Minimum mass detectable at 1-arcsec (G2)
46- 50 F5.3 Msun e_M1 rms uncertainty on M1
52- 56 F5.3 Msun M2 Minimum mass detectable at 2-arcsec (G2)
58- 62 F5.3 Msun e_M2 rms uncertainty on M2
64- 68 F5.3 Msun M5 Minimum mass detectable at 5-arcsec (G2)
70- 74 F5.3 Msun e_M5 rms uncertainty on M5
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Star Star name
11 A1 --- n_Star [a] Unresolved companion (1)
13- 14 I2 h RAh Right ascension (J2000)
16- 17 I2 min RAm Right ascension (J2000)
19- 22 F4.1 s RAs Right ascension (J2000)
24 A1 --- DE- Declination sign (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 34 F4.1 arcsec DEs Declination (J2000)
36- 45 A10 "DD/MM/YYYY" ObsDate Epoch of observation
47- 51 I5 --- Nfr Number of frames (G1)
53 A1 --- l_M0.5 Limit flag on M0.5
54- 58 F5.3 Msun M0.5 Minimum mass detectable at 0.5-arcsec (G2)
60- 64 F5.3 Msun e_M0.5 ? rms uncertainty on M0.5
66 A1 --- l_M1 Limit flag on M1
67- 71 F5.3 Msun M1 Minimum mass detectable at 1-arcsec (G2)
73- 77 F5.3 Msun e_M1 ? rms uncertainty on M1
79 A1 --- l_M2 Limit flag on M2
80- 84 F5.3 Msun M2 Minimum mass detectable at 2-arcsec (G2)
86- 90 F5.3 Msun e_M2 ? rms uncertainty on M2
92 A1 --- l_M5 Limit flag on M5
93- 97 F5.3 Msun M5 Minimum mass detectable at 5-arcsec (G2)
99-103 F5.3 Msun e_M5 ? rms uncertainty on M5
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Note (1): a : The companion candidate (Mason et al. 2009, Cat. J/AJ/137/3358)
at 0.237-arcsec separation could not be resolved.
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Global notes:
Note (G1): Numbers of frames observed, each frame with an exposure time
of 29.54ms.
Note (G2): Minimum mass detectable using the models by Baraffe et al.
(1998, Cat. J/A+A/337/403) and assuming an average age for each epoch
as listed in Table 5.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 28-Jan-2013