J/ApJ/682/L117 A spectroscopic orbit for Regulus (Gies+, 2008)
A spectroscopic orbit for Regulus.
Gies D.R., Dieterich S., Richardson N.D., Riedel A.R., Team B.L.,
McAlister H.A., Bagnuolo W.G.Jr, Grundstrom E.D., Stefl S., Rivinius T.,
Baade D.
<Astrophys. J., 682, L117-L120 (2008)>
=2008ApJ...682L.117G 2008ApJ...682L.117G
ADC_Keywords: Binaries, spectroscopic ; Stars, B-type ; Radial velocities
Keywords: binaries: spectroscopic - stars: early-type -
stars: individual (Regulus, α Leonis)
Abstract:
We present a radial velocity study of the rapidly rotating B star
Regulus that indicates the star is a single-lined spectroscopic
binary. The orbital period (40.11 days) and probable semimajor axis
(0.35AU) are large enough that the system is not interacting at
present. However, the mass function suggests that the secondary has a
low mass (M2>0.30M☉), and we argue that the companion may be a
white dwarf. Such a star would be the remnant of a former mass donor
that was the source of the large spin angular momentum of Regulus
itself.
Description:
Table 1 lists the sources and properties of the spectra of Regulus
used to measure radial velocity. The spectra from run numbers 1-8 were
made by us and have moderate resolving power and good S/N (usually
better than 100 per pixel). Other spectra are from online archives.
Objects:
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RA (2000) DE Designation(s)
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10 08 22.3 +11 58 02 NAME REGULUS = * alf Leo = HIP 49669
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 71 15 Journal of spectroscopy
table2.dat 35 168 Radial velocity measurements
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See also:
III/252 : Pulkovo radial velocities for 35493 HIP stars (Gontcharov, 2006)
III/190 : WEB Catalog of Radial Velocities (Duflot+ 1995)
J/MNRAS/389/869 : Multiplicity among bright stellar systems (Eggleton+, 2008)
J/AJ/133/889 : Faint companions of Hipparcos stars (Lepine+, 2007)
J/ApJ/663/960 : Radial velocities of Leo I stars (Sohn+, 2007)
J/AJ/126/2048 : NStars project: the Northern Sample. I. (Gray+, 2003)
J/A+A/379/162 : Binaries with post-T Tauri secondaries (Gerbaldi+, 2001)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq Running sequence number
4- 9 F6.1 yr Date1 Date of observation in Besselian year (first)
10 A1 --- --- [-]
11- 16 F6.1 yr Date2 ? Date of last observation in Besselian year
18- 36 A19 0.1nm Range Range in Angstrom
38- 43 I6 --- Power Resolving power (λ/Δλ)
45- 46 I2 --- Nsp Number of observed spectra
48- 71 A24 --- Tel Observatory/Telescope/Spectrograph
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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- 11 F11.3 d Date HJD
13- 17 F5.3 -- Phase Orbital phase from ascending node
19- 22 F4.1 km/s HRV Heliocentric radial velocity
24- 27 F4.1 km/s e_HRV Mean error on HRV
29- 32 F4.1 km/s O-C Observed minus calculated residual
34- 35 I2 -- Seq Running sequence number from Table 1
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 04-Nov-2010