J/ApJ/646/523 Exoplanet systems with stellar companions (Raghavan+, 2006)
Two suns in the sky: stellar multiplicity in exoplanet systems.
Raghavan D., Henry T.J., Mason B.D., Subasavage J.P., Jao W.-C.,
Beaulieu T.D., Hambly N.C.
<Astrophys. J., 646, 523-542 (2006)>
=2006ApJ...646..523R 2006ApJ...646..523R
ADC_Keywords: Stars, double and multiple ; Planets
Keywords: binaries: general - planetary systems - surveys
Abstract:
We present results of a reconnaissance for stellar companions to all
131 radial velocity-detected candidate extrasolar planetary systems
known as of 2005 July 1. Common proper-motion companions were
investigated using the multi-epoch STScI Digitized Sky Surveys and
confirmed by matching the trigonometric parallax distances of the
primaries to companion distances estimated photometrically. We also
attempt to confirm or refute companions listed in the Washington
Double Star Catalog (I/237), in the Catalogs of Nearby Stars Series
by Gliese and Jahreiss (V/70, in Hipparcos results (I/239, and in
Duquennoy & Mayor's radial velocity survey (1991A&A...248..485D 1991A&A...248..485D). Our
findings indicate that a lower limit of 30 (23%) of the 131 exoplanet
systems have stellar companions. We report new stellar companions to
HD 38529 and HD 188015 and a new candidate companion to HD 169830. We
confirm many previously reported stellar companions, including six
stars in five systems, that are recognized for the first time as
companions to exoplanet hosts. We have found evidence that 20 entries
in the Washington Double Star Catalog are not gravitationally bound
companions. At least three (HD 178911, 16 Cyg B, and HD 219449), and
possibly five (including HD 41004 and HD 38529), of the exoplanet
systems reside in triple-star systems. Three exoplanet systems (GJ 86,
HD 41004, and Cep) have potentially close-in stellar companions, with
planets at roughly Mercury-Mars distances from the host star and
stellar companions at projected separations of 20AU, similar to the
SunUranus distance. Finally, two of the exoplanet systems contain
white dwarf companions. This comprehensive assessment of exoplanet
systems indicates that solar systems are found in a variety of stellar
multiplicity environments - singles, binaries, and triples - and that
planets survive the post-main-sequence evolution of companion stars.
Description:
Our sample includes all known exoplanet systems detected by radial
velocity techniques as of 2005 July 1.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 57 131 Sample list of exoplanet systems searched for
companions
table2.dat 140 122 Exoplanet systems with stellar companions
refs.dat 99 52 References
table3.dat 42 20 WDS entries that are not gravitationally bound
companions
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See also:
I/237 : Washington Visual Double Star Catalog, 1996.0 (Worley+ 1996)
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
V/70 : Nearby Stars, Preliminary 3rd Version (Gliese+ 1991)
J/A+A/398/363 : Statistical properties of exoplanets II (Santos+, 2003)
J/MNRAS/372/1117 : SuperWASP exoplanetary transit survey (Christian+, 2006)
J/A+A/479/865 : CoRoT exoplanet candidates (Loeillet+, 2008)
J/ApJ/646/505 : Catalog of nearby exoplanets (Butler+, 2008)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Object name
12 A1 --- n_Name Note about ρ CrB (1)
14- 18 F5.3 arcsec/yr pm Proper motion
20- 24 F5.1 deg pmPA Position angle of proper motion
26- 32 F7.2 yr Epoch1 Epoch of the 1st observation (2)
34- 40 F7.2 yr Epoch2 Epoch of the 2nd observation (2)
42- 47 F6.3 arcsec Dist Proper motion distance between Epoch1 and
Epoch2
49- 51 A3 --- pmO Proper motion detectable in the DSS
frames? (3)
53 A1 --- CPM Companions detected via Common Proper
Motion (4)
55- 57 A3 --- Other Other companions (4)
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Note (1): 1 = We conclude that this system (ρ CrB) has either a
planetary or a stellar companion, but not both. See Section 2.3
for more details.
Note (2): In fractional year (Besselian) format.
Note (3): MAR = the proper motion was marginally detectable.
Note (4): A "?" following the companion ID indicates that the source
remains a candidate, and could not be confirmed or refuted with
confidence. The absence of a question mark indicates that the
companion is confirmed.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1 A1 --- St [CU] Status of stellar candidate companions,
(C)onfirmed or (U)nconfirmed
3- 4 I2 --- Seq Sequence number
6- 11 I06 --- HD HD number
12 A1 --- m_HD Multiplicity index on HD
14- 27 A14 --- Name Object name
29 A1 --- m_Name Stellar/Planetary companion identification
31- 33 A3 --- f_Name [12356, ] Flag(s) on companion (1)
35- 36 I2 h RAh Hour of Right Ascension (J2000) (2)
38- 39 I2 min RAm Minute of Right Ascension (J2000) (2)
41- 45 F5.2 s RAs Second of Right Ascension (J2000) (2)
47 A1 --- DE- Sign of the Declination (J2000) (2)
48- 49 I2 deg DEd Degree of Declination (J2000) (2)
51- 52 I2 arcmin DEm Arcminute of Declination (J2000) (2)
54- 57 F4.1 arcsec DEs Arcsecond of Declination (J2000) (2)
59- 65 F7.5 arcsec plx ? Hipparcos trigonometric parallax
67- 70 F4.1 pc Dist ? Distance
72 I1 --- u_Dist [4]? Distance assumes equal brightness (3)
74 A1 --- n_Dist [CPT] Determination code for Dist (4)
76- 82 A7 --- SpType Spectral type
84- 89 F6.2 arcsec rho ? Stellar and exoplanet angular separation
91- 93 I3 deg PA ? Stellar and exoplanet position angle
95-101 F7.1 AU PSep ? Projected primary & secondary star spatial
separation
103-108 F6.3 jovMass Msini ? Exoplanet mass in Jupiter masses
110-115 F6.3 AU asini ? Exoplanet spatial separation
117-121 F5.3 --- e ? Eccentricity
123-126 A4 --- Src [PWCDHOI ] Source(s) used to detect companion
stars (5)
128-140 A13 --- Ref Reference(s), in refs.dat file
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Note (1): Flag on Comp as follows:
1 = Known companion, but first identification of the star as a
companion to an exoplanet host.
2 = New stellar companion reported by this work.
3 = Separation and position angle are listed with respect to
component A. A and C have been referred to as Aa and Ab,
respectively in other publications, but we follow a consistent
naming convention, using uppercase letters to represent stars
and lowercase letters to denote planets.
5 = Separation and position angle are listed with respect to component B.
6 = New candidate companion reported by this work, via Kevin Apps.
Note (2): See text for more information.
Note (3): Flag on Dist as follows:
4 = Photometry obtained is for the BC pair. Distance estimate assumes
identical binary components.
Note (4): Determination code for Dist follows:
T = trigonometric parallax
C = calculated CCD photometric distance using relations from
Henry et al. (2004AJ....128.2460H 2004AJ....128.2460H)
P = calculated plate magnitude distance from SuperCOSMOS using
relations from Hambly et al. (2004AJ....128..437H 2004AJ....128..437H). If both
plate and CCD distance estimates are available, only the more
reliable CCD distance is listed.
Note (5): Source as follows:
P = a CPM detection using the multi-epoch DSS images
W = a companion listing in the WDS catalog
H = a Hipparcos catalog companion identification
C = a companion identification in the CNS catalog
D = a companion identification in Duquennoy & Mayor (1991A&A...248..485D 1991A&A...248..485D)
I = confirmation via our recent VRI images taken to verify CPM
O = the companion was not found by any of the above means, but
reported in one or more refereed papers
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 43 A20 --- Aut Author's name
45- 99 A55 --- Com Comments
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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- 10 A10 --- WDS WDS name (1)
12- 17 I6 --- HD HD number
19- 22 A4 --- Comp Component designation (1)
24- 26 I3 deg theta Position angle (2)
28- 32 F5.1 arcsec rho Separation angle (2)
34- 37 I4 yr Epoch Epoch of most recent observation (2)
39- 40 I2 --- Number Component number (1)
42 I1 --- Notes Individual notes (3)
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Note (1): Data listed here exactly as in the WDS catalog.
Note (2): Correspond to the most recent observation.
All data are as of 2005 June 20. Certain pairs of multiple systems
omitted from this table are confirmed to be gravitationally bound
companions (01368+4124AD, 11268+0301AB, 19091+3436Aa and Aa-B,
20283+1846AB, and 231590905A-BC and BC). One omitted pair
(201400052BC) has several speckle observations (Jonckheere 1911
(MNRAS, 72, 45), 1917 (MmRAS, 61, 1), 1944 (JO, 27, 11); Vanderdonck
1911(MNRAS, 72, 45); Van Biesbroeck 1960 (Publ. Yerkes Obs., 9, Pt. 2,
1960)) and several failed attempts (van den Bos 1949 (Union Obs.
Circ., 5, 312), 1960 (Publ. Yerkes Obs., 9, Pt. 1, 1960), 1963(AJ, 68,
582); Couteau 1954JO.....37...37C 1954JO.....37...37C; Baize 1957JO.....40..165B 1957JO.....40..165B) and is
hence inconclusive.
Note (3): Notes as follows:
1 = DSS multi-epoch plates do not show CPM for WDS entry. In fact,
proper motion of the primary star causes change in separation
and position angle, indicating that the companion is a
background star.
2 = Primary star is epsilon Eri, the well-studied exoplanet system.
WDS listing is based on a single speckle measure by Blazit et
al. (1977ApJ...214L..79B 1977ApJ...214L..79B). This system has been observed 13
other times and no companion was resolved (McAlister
1978PASP...90..288M 1978PASP...90..288M; Hartkopf & McAlister 1984PASP...96..105H 1984PASP...96..105H;
Oppenheimer et al. 2001, Cat. J/AJ/121/2189).
3 = Primary's mu=0.264"/yr at 251° from Hipparcos is not
detectable in DSS plates. For the WDS companion, SuperCOSMOS
lists mu=0.013"/yr at 91°, clearly not matching the
primary's.
4 = Primary does not show detectable proper motion in DSS plates.
Planet discovery paper, Frink et al. (2002ApJ...576..478F 2002ApJ...576..478F),
refuted the WDS entry based on distance estimate to WDS entry
and proper-motion comparisons.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 02-May-2008