J/ApJ/764/131 Long-term monitoring of Barnard's star velocity (Choi+, 2013)
Precise Doppler monitoring of Barnard's star.
Choi J., McCarthy C., Marcy G.W., Howard A.W., Fischer D.A., Johnson J.A.,
Isaacson H., Wright J.T.
<Astrophys. J., 764, 131 (2013)>
=2013ApJ...764..131C 2013ApJ...764..131C
ADC_Keywords: Radial velocities ; Stars, nearby ; Stars, double and multiple
Keywords: stars: individual: Gl 699; techniques: radial velocities
Abstract:
We present 248 precise Doppler measurements of Barnard's Star
(Gl 699), the second nearest star system to Earth, obtained from Lick
and Keck Observatories during the 25 years between 1987 and 2012. The
early precision was 20m/s but was 2m/s during the last 8 years,
constituting the most extensive and sensitive search for Doppler
signatures of planets around this stellar neighbor. We carefully
analyze the 136 Keck radial velocities spanning 8 years by first
applying a periodogram analysis to search for nearly circular orbits.
We find no significant periodic Doppler signals with amplitudes above
∼2m/s, setting firm upper limits on the minimum mass (Msini) of any
planets with orbital periods from 0.1 to 1000 days. Using a Monte
Carlo analysis for circular orbits, we determine that planetary
companions to Barnard's Star with masses above 2M⊕ and periods
below 10 days would have been detected. Planets with periods up to 2yr
and masses above 10M⊕ (0.03MJup) are also ruled out. A
similar analysis allowing for eccentric orbits yields comparable mass
limits. The habitable zone of Barnard's Star appears to be devoid of
roughly Earth-mass planets or larger, save for face-on orbits.
Previous claims of planets around the star by van de Kamp are strongly
refuted. The radial velocity of Barnard's Star increases with time at
4.515±0.002m/s/yr, consistent with the predicted geometrical effect,
secular acceleration, that exchanges transverse for radial components
of velocity.
Description:
We have observed Barnard's Star since 1987 at both the Lick and Keck
observatories. We obtained 40 observations of Barnard's Star from Lick
Observatory between 1987 and 2006, and 208 observations from Keck
spanning 15 years.
Objects:
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RA (ICRS) DE Designation(s) (Period)
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17 57 48.50 +04 41 36.2 Barnard's star = Gl 699 (P=3037)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 33 208 Keck radial velocities for Barnard's star
table3.dat 33 40 Lick radial velocities for Barnard's star
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See also:
J/A+A/561/A36 : The LickX Spectra library (Worthey+, 2014)
J/ApJS/210/5 : The twenty-five year Lick planet search (Fischer+, 2014)
J/AJ/147/20 : Spectroscopy of 447 nearby M dwarfs (Newton+, 2014)
J/ApJS/204/24 : Kepler planetary candidates. III. (Batalha+, 2013)
J/ApJ/750/L37 : Stellar parameters of low-mass KOIs (Muirhead+, 2012)
J/ApJ/748/93 : K-band spectra for 133 nearby M dwarfs (Rojas-Ayala+, 2012)
J/A+A/546/A61 : Radial velocities for XHIP catalogue (de Bruijne+, 2012)
J/A+A/541/A9 : M dwarfs activity & radial velocity (Gomes da Silva+, 2012)
J/ApJ/738/170 : False positive Kepler planet candidates (Morton+, 2011)
J/PASP/123/412 : Exoplanet Orbit Database (Wright+, 2011)
J/PASP/122/162 : Direct imaging of exoplanets (Beichman+, 2010)
J/MNRAS/403/1949 : UBV(RcIc)JHK photometry of HIP nearby stars (Koen+, 2010)
J/A+A/505/859 : M dwarfs radial velocities (Zechmeister+, 2009)
J/A+A/464/377 : HIP binaries with radial velocities (Frankowski+, 2007)
J/A+A/414/699 : Spectra of southern late-type dwarfs (Cincunegui+, 2004)
J/ApJS/141/503 : Radial Velocities for 889 late-type stars (Nidever+, 2002)
J/A+A/325/159 : Companions to M dwarfs within 5pc (Leinert+ 1997)
Byte-by-byte Description of file: table[23].dat
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Bytes Format Units Label Explanations
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1- 10 A10 "YYYY/MM/DD" Date UT date of observation
12- 20 F9.3 d BJD Barycentric Julian Date of observation;
BJD-2450000
22- 27 F6.2 m/s RVel [-39/26] Radial velocity
29- 33 F5.2 m/s e_RVel [2/33] The 1σ uncertainty in RVel
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 27-Oct-2014