J/ApJ/723/954 HIRES radial velocities of GJ 581 (Vogt+, 2010)
The Lick-Carnegie exoplanet survey: a 3.1 m⊕ planet in the habitable
zone of the nearby M3V star Gliese 581.
Vogt S.S., Butler R.P., Rivera E.J., Haghighipour N., Henry G.W.,
Williamson M.H.
<Astrophys. J., 723, 954-965 (2010)>
=2010ApJ...723..954V 2010ApJ...723..954V
ADC_Keywords: Radial velocities ; Stars, M-type ; Stars, double and multiple ;
Planets
Keywords: astrobiology - planetary systems -
stars: individual (GJ 581, HIP 74995)
Abstract:
We present 11 years of HIRES precision radial velocities (RVs) of the
nearby M3V star Gliese 581, combining our data set of 122 precision
RVs with an existing published 4.3-year set of 119 HARPS precision RVs
(Mayor et al., 2009, Cat. J/A+A/507/487). The velocity set now
indicates six companions in Keplerian motion around this star.
Differential photometry indicates a likely stellar rotation period of
∼94 days and reveals no significant periodic variability at any of the
Keplerian periods, supporting planetary orbital motion as the cause of
all the RV variations. The estimated equilibrium temperature of the
sixth planet, GJ 581g, is 228K, placing it squarely in the middle of
the habitable zone of the star and offering a very compelling case for
a potentially habitable planet around a very nearby star. This
detection, coupled with statistics of the incompleteness of
present-day precision RV surveys for volume-limited samples of stars
in the immediate solar neighborhood, suggests that η⊕, the
fraction of stars with potentially habitable planets, could well be on
the order of a few tens of percent.
Description:
The RVs presented herein were obtained with the HIRES spectrometer of
the Keck I telescope. For the Keck planet search program, we operate
the HIRES spectrometer at a spectral resolving power R∼70000 and
wavelength range of 3700-8000Å, though only the region
5000-6200Å (with iodine lines) is used in the present Doppler
analysis. The HIRES velocities of GJ 581 are presented in Table 1,
corrected to the solar system barycenter.
Objects:
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RA (2000) DE Designation(s)
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15 19 27.51 -07 43 19.4 GJ 581 = TYC 5594-1093-1
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 22 122 Radial velocities for GJ 581
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See also:
III/184 : 3rd Bibliog. Cat. of Stellar Radial Vel. (Barbier-Brossat+, 1994)
J/A+A/541/A9 : M dwarfs activity and radial velocity (Gomes da Silva+, 2012)
J/ApJ/709/168 : Eccentric orbits in exoplanets (Anglada-Escude+, 2010)
J/A+A/507/487 : GJ 581 radial velocity curve (Mayor+, 2009)
J/ApJ/705/1226 : Planet-bearing stars in Spitzer (Bryden+, 2009)
J/A+A/469/L43 : Radial velocities of Gl 581 (Udry+, 2007)
J/ApJ/649/1010 : Habitability of known exoplanetary systems (Jones+, 2006)
J/ApJS/141/503 : Radial Velocities for 889 late-type stars (Nidever+, 2002)
J/AJ/123/3356 : Palomar/MSU nearby star spectroscopic survey. III. (Gizis+,
2002)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 F10.5 d JD Julian Date of observation (JD-2450000)
12- 17 F6.2 m/s HRV Heliocentric radial velocity
19- 22 F4.2 m/s e_HRV Error in HRV (1)
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Note (1): The reported uncertainties reflect only one term in the overall error
budget, and result from a host of systematic errors from
characterizing and determining the PSF, detector imperfections,
optical aberrations, effects of under-sampling the Iodine lines, etc.
Two additional major sources of error are photon statistics and
stellar jitter. The former is already included in our Table 1
uncertainties. The latter varies widely from star to star (see section
2 for further explanations).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 20-Jul-2012