J/ApJ/701/1922 Radio interferometric planet search. I. (Bower+, 2009)
Radio interferometric planet search.
I. First constraints on planetary companions for nearby, low-mass stars from
radio astrometry.
Bower G.C., Bolatto A., Ford E.B., Kalas P.
<Astrophys. J., 701, 1922-1939 (2009)>
=2009ApJ...701.1922B 2009ApJ...701.1922B
ADC_Keywords: Stars, M-type ; Radio continuum ; Proper motions ;
Parallaxes, trigonometric
Keywords: astrometry - planetary systems - radio continuum: stars -
stars: activity - stars: early-type
Abstract:
Radio astrometry of nearby, low-mass stars has the potential to be a
powerful tool for the discovery and characterization of planetary
companions. We present a Very Large Array survey of 172 active
M dwarfs at distances of less than 10pc. Twenty-nine stars were
detected with flux densities greater than 100uJy. We observed seven of
these stars with the Very Long Baseline Array at milliarcsecond
resolution in three separate epochs. With a detection threshold of
500uJy in images of sensitivity 1σ∼100uJy, we detected three
stars three times (GJ 65B, GJ 896A, GJ 4247), one star twice (GJ 285),
and one star once (GJ 803). Two stars were undetected (GJ 412B and
GJ 1224). For the four stars detected in multiple epochs, residuals
from the optically determined apparent motions have an
root-mean-square deviation of ∼0.2 milliarcseconds, consistent with
statistical noise limits. Combined with previous optical astrometry,
these residuals provide acceleration upper limits that allow us to
exclude planetary companions more massive than 3-6MJup at a distance
of ∼1AU with a 99% confidence level.
Description:
Stars were drawn from two samples: active stars in the California &
Carnegie planet search (Wright 2005PASP..117..657W 2005PASP..117..657W) and X-ray selected
nearby stars which are too active for radial velocity searches
(NEXXUS; Schmitt & Liefke 2004, Cat. J/A+A/417/651). X-ray fluxes are
from the ROSAT all sky survey.
We used the VLA to observe our sample in 2005 June through September.
Observations were made at 5GHz in standard continuum mode.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 130 135 Stellar data
table2.dat 26 51 VLA detected star
table3.dat 22 134 VLA undetected star
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See also:
V/35 : CATALOGUE OF NEARBY STARS AND NEARBY STAR DATA PUBLISHED 1969-78
V/70 : Nearby Stars, Preliminary 3rd Version (Gliese+ 1991)
J/PASP/122/885 : Gliese catalog star/2MASS cross identifications (Stauffer+,
2010)
J/A+A/417/651 : NEXXUS ROSAT survey of coronal X-ray (Schmitt+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- GJ Gliese catalog identification
8- 9 I2 h RAh Hour of right ascension (J2000)
11- 12 I2 min RAm Minute of right ascension (J2000)
14- 18 F5.2 s RAs Second of right ascension (J2000)
20 A1 --- DE- Sign of declination (J2000)
21- 22 I2 deg DEd Degree of declination (J2000)
24- 25 I2 arcmin DEm Arcminute of declination (J2000)
27- 31 F5.2 arcsec DEs Arcsecond of declination (J2000)
33- 41 F9.2 mas ePos1 ? Positional error ellipse (major axis)
43- 51 F9.2 mas ePos2 ? Positional error ellipse (minor axis)
53- 55 I3 deg ePosPA ? Positional error ellipse (position angle)
57- 64 F8.2 mas/yr pmRA ? Proper motion along RA
66- 73 F8.2 mas/yr pmDE ? Proper motion along DE
75- 80 F6.2 mas/yr epm1 ? Proper motion error ellipse (major axis)
82- 87 F6.2 mas/yr epm2 ? Proper motion error ellipse (minor axis)
89- 91 I3 deg epmPA ? Proper motion error ellipse (position angle)
93- 98 F6.2 mas pi ? Annual parallax
100-104 F5.2 mas e_pi ? Annual parallax uncertainty
106-112 A7 --- SpType MK spectral type
114-118 F5.2 mag Bmag ? Apparent B-band magnitude
120-124 F5.2 mag Vmag ? Apparent V-band magnitude
126-130 F5.2 [10-7W] logLX ? Log of X-ray luminosity in erg/s
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Byte-by-byte Description of file: table2.dat table3.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- GJ Gliese catalog identification
9- 16 A8 "YYYYMMDD" Epoch Epoch of observation
18 A1 --- l_Flux Limit flag on Flux
19- 22 I4 uJy Flux Flux density at 5GHz
24- 26 I3 uJy e_Flux ? Flux density uncertainty
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 23-Sep-2011