J/AJ/148/118 Radial velocity curves of LMC ellipsoidal variables (Nie+, 2014)
Radial velocity curves of ellipsoidal red giant binaries in the Large Magellanic
Cloud.
Nie J.D., Wood P.R.
<Astron. J., 148, 118 (2014)>
=2014AJ....148..118N 2014AJ....148..118N
ADC_Keywords: Magellanic Clouds ; Stars, double and multiple ; Stars, giant ;
Radial velocities
Keywords: binaries: close - Magellanic Clouds - stars: AGB and post-AGB
Abstract:
Ellipsoidal red giant binaries are close binary systems where an
unseen, relatively close companion distorts the red giant, leading to
light variations as the red giant moves around its orbit. These
binaries are likely to be the immediate evolutionary precursors of
close binary planetary nebula and post-asymptotic giant branch and
post-red giant branch stars. Due to the MACHO and OGLE photometric
monitoring projects, the light variability nature of these ellipsoidal
variables has been well studied. However, due to the lack of radial
velocity curves, the nature of their masses, separations, and other
orbital details has so far remained largely unknown. In order to
improve this situation, we have carried out spectral monitoring
observations of a large sample of 80 ellipsoidal variables in the
Large Magellanic Cloud and we have derived radial velocity curves. At
least 12 radial velocity points with good quality were obtained for
most of the ellipsoidal variables. The radial velocity data are
provided with this paper. Combining the photometric and radial
velocity data, we present some statistical results related to the
binary properties of these ellipsoidal variables.
Description:
We initially selected 86 sequence E candidates from those given in
Soszynski et al. 2004 (cat. J/AcA/54/347).
The radial velocity observations were taken using the Wide Field
Spectrograph (WiFeS) mounted on the Australian National University
2.3m telescope at Siding Spring Observatory. WiFes has six gratings.
For our observations, the gratings B7000 (wavelength coverage of
4184-5580Å) and I7000 (wavelength coverage of 6832-9120Å) were
chosen for the blue and red CCD, respectively. These two gratings give
a two-pixel resolution R=7000.
We carried out 18 weeks of radial velocity monitoring, from 2010
September to 2012 March.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 45 1077 Radial velocities Vr and 1σ errors
σVr in km/s
table2.dat 97 86 Properties of the observed ellipsoidal variables
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See also:
II/247 : Variable Stars in the Large Magellanic Clouds (MACHO, 2001)
I/244 : OGLE General Catalog of Stars. I. (Szymanski+ 1996)
J/MNRAS/421/2616 : LMC eccentric ellipsoidal red giant binaries
(Nicholls+, 2012)
J/MNRAS/405/1770 : LMC red giants in E sequence (Nicholls+, 2010)
J/MNRAS/399/2063 : LMC red giants in D sequence (Nicholls+, 2009)
J/AJ/136/1242 : LMC long-period variables from MACHO (Fraser+, 2008)
J/A+A/439/559 : OGLE eclipsing binaries (Groenewegen+, 2005)
J/MNRAS/353/705 : OGLE Variables in Magellanic Clouds (Ita+, 2004)
J/MNRAS/348/1439 : OGLE II Galactic center proper motions (Sumi+, 2004)
J/AcA/53/1 : OGLE eclipsing binaries in LMC (Wyrzykowski+, 2003)
J/AcA/52/129 : DIA OGLE2 candidate variable stars catalog (Wozniak+, 2002)
J/AcA/49/223 : BVI photometry of OGLE LMC Cepheids (Udalski+, 1999)
http://macho.anu.edu.au/ : MACHO Home Page
http://ogle.astrouw.edu.pl/ : OGLE Home Page
ftp://ftp.astrouw.edu.pl/ogle/ogle2 : OGLE-II
ftp://ftp.astrouw.edu.pl/ogle/ogle3 : OGLE-III
ftp://ftp.astrouw.edu.pl/ogle/ogle4 : OGLE-IV
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [OGLE]
5- 22 A18 --- OGLEII OGLE II designation (HHMMSS.ss+DDMMSS.s, J2000)
24- 33 F10.5 d HJD Heliocentric Julian date (HJD-2450000)
35- 40 F6.2 km/s HRV Heliocentric radial velocity
42- 45 F4.2 km/s e_HRV 1σ error in HRV
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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- 4 A4 --- --- [OGLE]
5- 22 A18 --- OGLEII OGLE II designation (HHMMSS.ss+DDMMSS.s, J2000)
24- 29 F6.2 d Per [72/642] Orbital period
31- 35 F5.2 mag <Imag> Mean magnitude in I band
37- 41 F5.2 mag <Vmag> ? Mean magnitude in V band
43- 47 F5.2 mag <Bmag> ? Mean magnitude in MACHO blue band
49- 53 F5.2 mag <Rmag> ? Mean magnitude in MACHO red band
55- 59 F5.2 mag <Kmag> Mean magnitude in 2MASS Ks band
61- 65 F5.3 mag <Iamp> Mean amplitude of light variability in the I band
67- 69 I3 km/s DHRV [5/120]? Full radial velocity amplitude
71- 74 I4 Lsun Lum Luminosity
76- 79 I4 K Teff Effective temperature
81- 83 I3 Rsun <Rad> [40/156] Mean radius
85 I1 --- Loc [1/2] Location of the star on the Imag-logPeriod
and W-logPeriod planes (Figure1 in the paper) (1)
87- 91 A5 --- Type [e +sr,] Binary type (2)
93- 97 A5 --- LC Object which has OGLE III light curve data
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Note (1): Location of the ellipsoidal variable candidate in Figure1:
1 = Star below the blue line in Figure1. The blue line is a line parallel
to the main part of sequence E;
2 = Star above the blue line (star brighter than normal for their period and
expected to be intermediate-mass star).
Note (2): Binary type defined as:
e = eccentric;
+sr = binary whose red giant shows semi-regular variability as well as
ellipsoidal variability.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 10-Dec-2014