J/ApJ/700/1349 Radial velocities of Capella (Torres+, 2009)
Binary orbit, physical properties, and evolutionary state of capella
(α Aurigae).
Torres G., Claret A., Young P.A.
<Astrophys. J., 700, 1349-1381 (2009)>
=2009ApJ...700.1349T 2009ApJ...700.1349T
ADC_Keywords: Binaries, spectroscopic ; Radial velocities ; Interferometry
Keywords: binaries: general - binaries: spectroscopic - stars: abundances -
stars: evolution - stars: fundamental parameters -
stars: individual (Capella)
Abstract:
We report extensive radial velocity measurements of the two giant
components of the detached, 104 day period binary system of Capella.
Our highly accurate three-dimensional orbital solution based on all
existing spectroscopic and astrometric observations including our
own yields much improved masses for the primary and secondary of
2.466±0.018M☉ and 2.443±0.013M☉, with relative errors
of only 0.7% and 0.5%, respectively. The mass ratio is considerably
closer to unity than previously believed, which has an impact on
assessing the evolutionary state of the system. Improved values
are presented also for the radii (11.87±0.56R☉ and
8.75±0.32R☉), effective temperatures (4920±70K and 5680±70K),
and luminosities (79.5±4.8L☉ and 72.1±3.6L☉). The
distance is determined to be 13.042±0.028pc, based on the accurate
orbital parallax. The projected rotational velocities and individual
rotation periods are also known. Capella is unique among evolved stars
in that, in addition to all of the above, the chemical composition is
known as well.
Description:
Spectroscopic observations of Capella were conducted at the
Harvard-Smithsonian Center for Astrophysics (CfA) using the 1.5m
Wyeth reflector at the Oak Ridge Observatory (Harvard, Massachusetts),
beginning in 1996 October and continuing through 1999 November.
Objects:
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RA (2000) DE Designation(s)
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05 16 41.4 +45 59 53 NAME CAPELLA = * alf Aur
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 64 162 CfA radial velocity measurements of Capella
table3.dat 49 342 Historical radial velocity measurements of the
primary component of Capella
table4.dat 68 71 Interferometric measurements of Capella
published in polar coordinates
table5.dat 67 32 Interferometric measurements of Capella
published in Cartesian coordinates
table6.dat 68 57 Speckle and imaging measurements of Capella
table7.dat 46 41 Hipparcos measurements of Capella and
corresponding O-C residuals
refs.dat 77 44 References
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See also:
J/A+A/531/A89 : Spectroscopic orbit of Capella (Weber+, 2011)
J/A+A/422/627 : Nearby multiple stars speckle interferometry (Balega+, 2004)
J/ApJS/131/561 : Double stars with PISCO at Pic du midi (Scardia+, 2000)
J/AJ/119/3084 : ICCD speckle obs. of binary stars. XXIII. (Hartkopf+, 2000)
J/AJ/117/548 : 1997 WIYN binary stars speckle observations (Horch+, 1999)
J/AJ/106/1639 : Speckle observations of binary stars (McAlister+ 1993)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian Date
14- 21 F8.3 yr JYr Julian year of observation
23- 28 F6.2 km/s RVA Primary radial velocity
30- 35 F6.2 km/s RVB Secondary radial velocity
37- 40 F4.2 km/s e_RVA The 1σ error in RVA
42- 45 F4.2 km/s e_RVB The 1σ error in RVB
47- 51 F5.2 km/s (O-C)A Primary (O-C) residual
53- 57 F5.2 km/s (O-C)B Secondary (O-C) residual
59- 64 F6.4 --- Phase Orbital phase
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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- 12 F12.4 d HJD Heliocentric Julian Date
14- 21 F8.3 yr JYr Julian year
23- 28 F6.2 km/s RVA Primary radial velocity
30- 33 F4.2 km/s e_RVA The 1σ error in RVA
35- 39 F5.2 km/s (O-C)A Primary (O-C) residual
41- 46 F6.4 --- Phase Orbital phase
48- 49 I2 --- Ref Source reference (see refs.dat file)
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Byte-by-byte Description of file: table[46].dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian Date
14- 21 F8.3 yr JYr Julian year
23- 28 F6.2 deg theta ? Position angle
30- 34 F5.2 mas rho ? Angular separation
36- 40 F5.2 deg e_theta ? The 1σ error in theta
42- 45 F4.2 mas e_rho ? The 1σ error in rho
47- 52 F6.2 deg (O-C)t ? The position angle (O-C) residual
54- 58 F5.2 mas (O-C)r ? The angular separation (O-C) residual
60- 65 F6.4 --- Phase Orbital phase
67- 68 I2 --- Ref Source reference (see refs.dat file)
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian Date
14- 21 F8.3 yr JYr Julian year
23- 28 F6.2 mas DelX Relative X separation
30- 35 F6.2 mas DelY Relative Y separation
37- 40 F4.2 mas e_DelX The 1σ error in DelX
42- 45 F4.2 mas e_DelY The 1σ error in DelY
47- 51 F5.2 --- (O-C)X Relative X separation (O-C) residual
53- 57 F5.2 --- (O-C)Y Relative Y separation (O-C) residual
59- 64 F6.4 --- Phase Orbital phase
66- 67 I2 --- Ref Source reference (see refs.dat file)
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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- 12 F12.4 d HJD Heliocentric Julian Date
14- 21 F8.3 yr JYr Julian year
23- 27 F5.2 mas DelV Abscissa residual measurement
29- 33 F5.2 mas e_DelV The 1σ error in DelV
35- 39 F5.2 mas (O-C)V Abscissa residual (O-C) residual
41- 46 F6.4 --- Phase Orbital phase
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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- 42 A19 --- Aut Author's name(s)
44- 77 A34 --- Comm Comment
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 28-Jul-2011