J/ApJ/783/3 Radial velocities of 1 Gem (Lane+, 2014)
The orbits of the triple-star system 1 Geminorum from phases differential
astrometry and spectroscopy.
Lane B.F., Muterspaugh M.W., Griffin R.F., Scarfe C.D., Fekel F.C.,
Williamson M.H., Eaton J.A., Shao M., Colavita M.M., Konacki M.
<Astrophys. J., 783, 3 (2014)>
=2014ApJ...783....3L 2014ApJ...783....3L (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, spectroscopic ; Radial velocities
Keywords: binaries: spectroscopic - stars: fundamental parameters -
stars: individual: 1 Gem - techniques: interferometric
Abstract:
We have used precise differential astrometry from the Palomar
High-precision Astrometric Search for Exoplanet Systems project and
radial-velocity measurements covering a time span of 40yr to determine
the orbital parameters of the 1 Geminorum triple system. We present
the first detection of the spectral lines of the third component of
the system, together with precise mass (0.5%) and distance (0.15%)
determinations for this system. In addition, our astrometry allows us
to make the first determination of the mutual inclination of the
orbits.
Description:
Extensive radial-velocity measurements of the 1 Gem system have been
obtained in four separate campaigns spanning 40yr, including data from
eight different instruments.
Between 1969 and 2009 R.F.G. acquired a total of 128 observations of 1
Gem using the original radial-velocity spectrometer at Cambridge; a
second-generation, computerized instrument at Palomar; the CORAVEL
spectrometer at Haute Provence Observatory (OHP), and most recently,
the Cambridge CORAVEL. The "Cambridge CORAVEL" operates at the Coude
focus of the 36inch reflector on the home site of the Cambridge
Observatories, Madingley Road, Cambridge, England. The Cambridge and
Palomar data are referred to as data set A, while the OHP data are
labeled set B. The data for components A and Ba are provided in
Table1.
A series of observations of 1 Gem has been obtained by C.D.S. with the
Dominion Astrophysical Observatory (DAO) radial-velocity spectrometer.
Observations were begun early in 1980 and continued until the end of
2003. The DAO velocities of components A and Ba are listed in Table2.
The total number of acceptable velocities from DAO radial-velocity
scanner observations is 123 of the primary star and 107 of the
brighter component of the close pair. The third component was not
detectable in the DAO traces. We identify the DAO observations as data
set C.
From 1983 through 2009 F.C.F. obtained observations at the Kitt Peak
National Observatory (KPNO) with the 0.9m coude feed telescope, coude
spectrograph, and several different CCD detectors. All of the
spectrograms were acquired with a Texas Instruments (TI) CCD except
for five that were obtained in 1983 with an RCA CCD and a single
observation in 2008 September with a Tektronix CCD. All those
observations were centered near 6430Å and had typical
signal-to-noise ratios of about 250. The numerous TI CCD spectra have
a wavelength range of just 84Å and a resolution of 0.21Å. The 86
velocities of component A and 80 of component Ba are listed in Table3.
They are identified as data set D.
From 2003 through 2009 J.A.E. acquired 522 spectrograms with the
Tennessee State University 2m Automatic Spectroscopic Telescope (AST)
situated at Fairborn Observatory near Washington Camp in the Patagonia
Mountains of southeastern Arizona, fiber-fed echelle spectrograph, and
a 2048*4096 SITe ST-002A CCD. The echelle spectrograms have 21 orders,
covering the wavelength range 4920-7100Å with an average resolution
of 0.17Å. The typical signal-to-noise ratio is ∼50. The AST spectra
are referred to as data set E (see Table4).
Objects:
--------------------------------------------------------------
RA (ICRS) DE Designation(s) (Period)
--------------------------------------------------------------
06 04 07.22 +23 15 48.0 1 Geminorum = HR 2134 (P=4877.6)
--------------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 64 128 1 Gem radial-velocity data sets A and B
(Palomar, OHP, and Cambridge)
table2.dat 64 123 1 Gem radial-velocity data set C (DAO)
table3.dat 64 86 1 Gem radial-velocity data set D (KPNO)
table4.dat 64 522 1 Gem radial-velocity data set E (AST)
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See also:
J/AJ/140/1579 : PHASES astrometry data archive (Muterspaugh+, 2010)
J/MNRAS/389/925 : Triple and quadruple stars (Tokovinin, 2008)
J/ApJ/636/1020 : kappa Peg astrometry and velocities (Muterspaugh+, 2006)
J/AJ/130/2866 : Differential astrometry of δ Equ (Muterspaugh+, 2005)
J/A+A/384/1030 : Orientation of orbits in triple stars (Sterzik+, 2002)
J/A+AS/124/75 : Multiple star catalogue (MSC) (Tokovinin 1997-1999)
Byte-by-byte Description of file: table[1234].dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 d HJD Heliocentric Julian Date (HJD-2400000.5)
12- 15 F4.1 km/s RVA ? Radial velocity of A component
17- 20 F4.2 km/s e_RVA ? The 1σ uncertainty in RVA
22- 26 F5.2 km/s O-CA ? The O-C fit residual for A component
28- 32 F5.1 km/s RVBa ? Radial velocity of Ba component
34- 37 F4.2 km/s e_RVBa ? The 1σ uncertainty in RVBa
39- 43 F5.2 km/s O-CBa ? The O-C fit residual for Ba component
45- 49 F5.1 km/s RVBb ? Radial velocity of Bb component
51- 54 F4.2 km/s e_RVBb ? The 1σ uncertainty in RVBb
56- 60 F5.2 km/s O-CBb ? The O-C fit residual for Bb component
62- 64 I3 --- Obs ? Source code (213, 218, 312, 313, or 412) (1)
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Note (1): Number of data set defined as:
213 = "old Cambridge";
218 = Palomar;
313 = CORAVEL at Haute Provence Observatory (OHP);
312 = pre-2005 Cambridge CORAVEL;
412 = post-2005 Cambridge CORAVEL.
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 25-May-2016