J/AJ/151/26 Spectroscopy of five γ Dor variables (Fekel+, 2016)
The spectroscopic orbits of five γ Doradus stars.
Fekel F.C., Henry G.W., Pourbaix D.
<Astron. J., 151, 26 (2016)>
=2016AJ....151...26F 2016AJ....151...26F (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, spectroscopic ; Binaries, orbits ; Stars, variable ;
Radial velocities
Keywords: binaries: spectroscopic - stars: oscillations
Abstract:
We have determined the spectroscopic orbits of five γ Dor
variables, HD776, HD6568, HD17310, HD19684, and HD62196. Their orbital
periods range from 27.8 to 1163days and their eccentricities from 0.01
to 0.65. Of the five systems, only HD19684 shows lines of its binary
companion, but those lines are always so weak and blended with the
lines of the primary that we were unable to measure them
satisfactorily. The velocity residuals of the orbital fits were
searched for periodicities associated with pulsation. No clear,
convincing case for velocity periodicities in the residuals was found
in four of the five stars. However, for HD17310 we identified a period
of 2.13434days, a value in agreement with the largest amplitude period
previously found photometrically for that star. The velocity residuals
of HD62196 have a long-term trend suggesting that it is a triple
system.
Description:
From 2001 through 2011 we obtained observations at the Kitt Peak
National Observatory (KPNO) with the coude feed telescope and coude
spectrograph. The vast majority were acquired with a TI CCD detector,
and those spectrograms are centered at 6430Å, cover a wavelength
range of 84Å and have a resolution of 0.21Å. In 2004 September
and October three spectra (one for HD17310 and two for HD19684) were
obtained in the blue, centered at 4500Å. They cover the same
wavelength range and have the same resolution as the red wavelength
spectra. The TI CCD was unavailable in 2008 September, so a Tektronics
CCD, designated T1KA, was used instead. With that CCD the spectrum was
centered at 6400Å. Although the wavelength range covered by the
chip increased to 172Å, the resolution decreased to 0.35Å.
Beginning in 2010 September we acquired spectra with a CCD, consisting
of a 2600*4000 array of 12µm pixels, that was made by Semiconductor
Technology Associates and designated STA2. With STA2 the spectrum was
once again centered at 6430Å, and the much larger size of the
detector produced a wavelength range of 336Å. The spectrograph slit
was set so that the STA2 spectra have the same resolution as those
acquired with the TI CCD although there is some worsening of the
resolution at both ends of the STA2 spectra. Our KPNO spectra have
signal-to-noise ratios (S/N) of 50-100.
Starting in 2006, we collected additional spectrograms with the
Tennessee State University (TSU) 2m Automatic Spectroscopic Telescope
(AST) and a fiber-fed echelle spectrograph, situated at Fairborn
Observatory near Washington Camp in the Patagonia Mountains of
southeastern Arizona. Through 2011 June the detector was a 2048*4096
SITe ST-002A CCD with 15µm pixels. These AST echelle spectrograms
have 21 orders that cover the wavelength range 4920-7100Å, and most
have an average resolution of 0.17Å, although a few have a slightly
lower resolution of 0.24Å. The S/N ranged from 30 to 50 at
6000Å. In the summer of 2011 the SITe CCD detector and its dewar
were replaced by a Fairchild 486 CCD with 4K*4K 15µm pixels and a
new dewar. This larger CCD results in echelle spectrograms that have
48 orders that span the wavelength range 3800-8260Å. Because
different diameter fibers were used at various times, the resolution
for these spectra was either 0.24 or 0.4Å, which resulted in S/N
that ranged from 60 to 100 at 6000Å.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 48 5 Basic properties
table2.dat 125 5 Orbital elements and related parameters
table3.dat 32 42 Radial velocities of HD 776
table4.dat 32 106 Radial velocities of HD 6286
table5.dat 32 205 Radial velocities of HD 17310
table6.dat 32 101 Radial velocities of HD 19684
table7.dat 32 124 Radial velocities of HD 62196
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See also:
B/sb9 : 9th Catalogue of Spectroscopic Binary Orbits (Pourbaix+ 2004-2014)
J/AJ/149/83 : Radial velocity curves of HD 207651 (Fekel+, 2015)
J/AJ/145/111 : Radial velocities of five spectroscopic binaries (Fekel+, 2013)
J/AJ/142/39 : Sample of 114 γ Doradus candidates (Henry+, 2011)
J/AJ/133/1421 : BV differential photometry of 11 gamma Dor stars (Henry+, 2007)
J/AJ/132/1910 : HD 131861 radial velocities and VRI light curves (Fekel+, 2006)
J/AJ/129/1001 : Radial velocities of HD 166181 (Fekel+, 2005)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- HD HD identifier
7- 11 I5 --- HIP [986/37802] HIP number
13- 23 A11 --- SpT Spectral type
25- 28 F4.2 mag Vmag [6.9/7.8] V band magnitude (1)
30- 34 F5.3 mag B-V [0.3/0.38] B-V color index (1)
36- 40 F5.2 mas plx [9/14.8] Parallax (2)
42- 45 F4.2 mas e_plx [0.5/1.7] Uncertainty in plx
47- 48 I2 km/s vsini [6/64] Rotational velocity
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Note (1): From HIP (Perryman & ESA 1997, Cat. I/239).
Note (2): From HIP2 (van Leeuwen 2007, Cat. I/311).
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- HD HD identifier
7- 15 F9.4 d Per [27.8/1163.4] Period
17- 22 F6.4 d e_Per [0.001/1.6] Uncertainty in Per
24- 33 F10.2 d T Heliocentric Julian date of periastron
passage
35- 39 F5.2 d e_T [0.4/72.2] Uncertainty in T
41- 46 F6.4 --- e [0.01/0.7] Eccentricity
48- 53 F6.4 --- e_e [0.005/0.02] Uncertainty in e
55- 59 F5.1 deg omega [21.7/332.8] Longitude of periastron ω
61- 64 F4.1 deg e_omega [2.5/22.3] Uncertainty in omega
66- 71 F6.3 km/s K [7.1/22.6] Velocity semiamplitude
73- 77 F5.3 km/s e_K [0.03/0.3] Uncertainty in K
79- 85 F7.3 km/s gamma [-28.4/22.1] Center-of-mass velocity γ
87- 91 F5.3 km/s e_gamma [0.02/0.2] Uncertainty in gamma
93- 95 F3.1 km/s rms [0.3/2.2] Radial velocity rms residual to the
computed orbit (3)
97-103 F7.3 Gm asini [4.9/151.8] Minimum semimajor axis of the
primary (in units of 106km) (4)
105-109 F5.3 Gm e_asini [0.08/1.9] Uncertainty in asini
111-117 F7.5 Msun f(m) [0.002/0.3] Mass function (4)
119-125 F7.5 Msun e_f(m) [0.00024/0.011] Uncertainty in f(m)
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Note (3): Provides an indication of how strongly the velocities are affected by
pulsation.
Note (4): Computed from the orbital elements.
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Byte-by-byte Description of file: table[34567].dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 d HJD [52013/57190] Heliocentric Julian Date (HJD-2400000)
12- 16 F5.3 --- Phase [0/1] Fractional phase
18- 22 F5.1 km/s RV [-34.1/45.5] Radial velocity of primary
24- 27 F4.1 km/s O-C [-5.9/6.1] Velocity residual of primary
29- 32 A4 --- Obs Observatory (KPNO=Kitt Peak National Observatory,
or Fair=Fairborn observatory)
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 03-Oct-2016