J/AJ/149/83 Radial velocity curves of HD 207651 (Fekel+, 2015)
HD 207651: a composite spectrum triple system.
Fekel F.C.
<Astron. J., 149, 83 (2015)>
=2015AJ....149...83F 2015AJ....149...83F
ADC_Keywords: Binaries, spectroscopic ; Radial velocities
Keywords: binaries: spectroscopic - stars: early-type - stars: late-type -
stars: fundamental parameters - stars: individual: HD 207651
Abstract:
From numerous radial velocities obtained at KPNO and Fairborn
Observatory, we have determined the orbital elements of the composite
spectrum triple system HD 207651. This system consists of a
broad-lined A8 V star and an unseen M dwarf companion in a
1.470739days orbit. Variations of the center-of-mass velocity of this
short-period system and velocity variations of a narrow-lined F7: V
star have an orbital period of 724.1days or 1.98yr and an eccentricity
of 0.39. The revised Hipparcos parallax, corresponding to a distance
of 255pc, appears to be too small to yield consistent properties.
Instead, we adopt a distance of 150pc.
Description:
We began our observation of HD 207651 at the Kitt Peak National
Observatory (KPNO) in 2000 July and continued through 2012 May. At
KPNO we used the coude feed telescope, coude spectrograph, and several
different detectors to acquire 51 spectrograms. We obtained the vast
majority with a Texas Instruments (TI) CCD. Those spectra are centered
primarily in the red at 6430Å, cover a wavelength range of just
84Å, and have a resolution of 0.21Å or a resolving power of
about 30000. Two of the spectrograms are centered at a blue wavelength
of 4500Å and have the same wavelength range and resolution,
producing a resolving power of 21000. In 2008 September the TI CCD was
unavailable, and so we acquired a single spectrum of HD 207651 with a
Tektronics CCD, identified as T1KA. That spectrum was centered at
6400Å with the wavelength coverage increased to 172Å, but the
resolving power decreased to 19000. After the TI CCD was retired in
2010 September, we obtained spectra with a CCD made by Semiconductor
Technology Associates, designated STA2, which consists of a 2600*4000
array of 12µm pixels. The increased array size produced a
wavelength range of 336Å for spectra centered at 6430Å. The
resolution was the same as our red wavelength TI CCD spectra, but
there is some worsening of the resolution at both ends of these recent
STA2 spectra. The spectra have typical signal-to-noise ratios (S/N) of
about 150.
From 2009 October through 2014 October, we acquired 83 useful
observations of HD 207651 with the Tennessee State University 2m
telescope, fiber-fed echelle spectrograph, and a CCD detector at
Fairborn Observatory in southeastern Arizona. Initially, the detector
was a 2048*4096 SITe ST-002A CCD with 15µm pixels. The echelle
spectrograms have 21 orders that cover the wavelength range
4920-7100Å with an average resolution of 0.17Å, corresponding to
a resolving power of 35000 at 6000Å. While a typical S/N value for
these spectra is 60, large temperature variations of the dewar caused
reduced S/N of some spectra. During the summer of 2011, the SITe CCD
and its dewar were replaced with a Fairchild 486 CCD that has a
4096*4096 array of 15µm pixels and a new dewar. The expanded
wavelength coverage enabled by the new CCD ranges from 3800 to
8600Å, and the resolution of these echelle spectra is 0.24Å or a
resolving power of 25000 at 6000Å. This new combination produced
improved S/N generally ranging from 100 to 150.
Objects:
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RA (ICRS) DE Designation(s) (Period)
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21 50 08.23 +19 25 26.4 HD 207651 = HIP 107786 (P=1.4707386)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 51 134 Radial velocities of HD 207651
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See also:
B/sb9 : 9th Catalogue of Spectroscopic Binary Orbits (Pourbaix+ 2004-2014)
J/AJ/149/63 : Radial velocities of HD 54371, HR 2692, 16 UMa (Fekel+, 2015)
J/AJ/145/111 : Radial velocities of five spectroscopic binaries (Fekel+, 2013)
J/AJ/132/1910 : HD 131861 radial velocities and VRI light curves (Fekel+, 2006)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 d HJD Heliocentric Julian Date
11 A1 --- f_HJD [a] Indicates a 4500Å region
13- 17 F5.3 --- LPhase [0/1] Phase in the long-period orbit
19- 23 F5.1 km/s RVB [-24.6/15.2] Radial velocity of the narrow-lined
component B
25- 28 F4.1 km/s O-CB Residual to the orbit of component B (O-C)B
30- 34 F5.1 km/s RVAa [-49/17.1] Radial velocity of the broad-lined
component Aa
36- 40 F5.2 km/s O-CAa Residual of component Aa (1)
42- 46 F5.3 --- SPhase [0/1] Phase in the short-period orbit
48- 51 A4 --- Obs Observatory (Fair or KPNO) (2)
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Note (1): Residual to the combined fit of the short- and long-period velocity
variations.
Note (2): Observatory codes defined as below:
Fair = Fairborn Observatory;
KPNO = Kitt Peak National Observatory.
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History:
From electronic version of the journal
(End) Sylvain Guehenneux [CDS] 02-Mar-2015