J/AJ/156/231 Radial velocities of 2 VY Sculptoris-type CV stars (Weil+, 2018)
An optical study of two VY Sculptoris-type cataclysmic binary stars: V704 And
and RX J2338+431.
Weil K.E., Thorstensen J.R., Haberl F.
<Astron. J., 156, 231 (2018)>
=2018AJ....156..231W 2018AJ....156..231W (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, cataclysmic ; Stars, variable ; Radial velocities ;
Photometry, infrared ; Photometry, SDSS
Keywords: novae, cataclysmic variables
Abstract:
We report observations of the known cataclysmic variable star (CV)
V704 And, and also confirm that the optical counterpart of the ROSAT
Galactic Plane Survey source RX J2338+431 is a heretofore-neglected CV.
Photometric and spectroscopic observations from MDM Observatory show both
systems to be nova-like variables that exhibit dips of 4-5 mag from their
mean brightnesses, establishing them as members of the VY Scl subclass.
From high-state emission-line radial velocities, we determine orbital
periods of 0.151424(3) days (3.63 hr) for V704 And and 0.130400(1) days
(3.13 hr) for RX J2338+431. In V704 And, we find that the Hα
emission-line measures cluster into distinct regions on a plot of
equivalent width versus full width at half-maximum, which evidently
correspond to high, intermediate, and low photometric states. This allows
us to assign spectra to photometric states when contemporaneous photometry
is not available, an apparently novel method that may be useful in studies
of other novalikes. Our low-state spectra of RX J2338+431 show features
of an M-type secondary star, from which we estimate a distance of
890±200 pc, in good agreement with the Gaia DR2 (Cat. I/345) parallax.
Description:
The spectral observations reported here are from the 2.4 m Hiltner
telescope and the 1.3 m McGraw-Hill telescope at MDM Observatory on
Kitt Peak, Arizona. At both telescopes, nearly all observations were
taken with the "modspec" spectrograph with a 1.1" slit and "Echelle"
detector, a SITe 20482 CCD giving a dispersion of 2Å/pixel between
4210 and 7500Å, with declining throughput toward the ends of the
spectral range. When Echelle was unavailable a similar 10242 SITe
detector ("Templeton") was used, which covered from 4660 to 6730Å.
For a few spectra we used the Mark III grism spectrograph, which covered
4580 to 6850Å at 2.3Å/pixel resolution. We used an incandescent
lamp for a flat field, derived the wavelength calibration from
observations of Hg, Ne, and Xe lamps, and observed flux standard stars
in twilight when the weather was clear.
Spectral observations for V704 And were taken between 2001 January and
2016 June, and for RX J2338+431 between 1999 October and 2002 October.
Tables 3 and 4 list the times of observation. Exposure were typically
480 s, but varied from 180 to 1200 s.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 112 2 Object properties
table3.dat 21 162 V704 And radial velocities
table4.dat 21 154 RX J2338+431 radial velocities
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See also:
V/110 : Catalog of Cataclysmic Variables (Downes+ 2001)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/PASP/122/1285 : Radial-velocities of 20 cataclysmic var. (Thorstensen+, 2010)
J/AJ/146/107 : Velocity curves of 10 cataclysmic binaries
(Thorstensen+, 2013)
J/AJ/149/128 : Radial velocities of 29 cataclysmic variables
(Thorstensen+, 2015)
J/AJ/150/170 : Radial velocities of 7 cataclysmic binaries (Halpern+, 2015)
J/AJ/152/226 : Radial velocities of 35 cataclysmic variables
(Thorstensen+, 2016)
J/A+A/617/A16 : VY Scl reduced spectra + radial velocities
(Schmidtobreick+, 2018)
J/AJ/155/247 : Radial velocities of 6 X-ray cataclysmic binaries
(Halpern+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Star Star name (V704 And or RX J2338+431)
14- 15 I2 h RAh Hour of Right Ascension (J2000) (1)
17- 18 I2 min RAm Minute of Right Ascension (J2000) (1)
20- 26 F7.4 s RAs Second of Right Ascension (J2000) (1)
28 A1 --- DE- Sign of the Declination (J2000) (1)
29- 30 I2 deg DEd Degree of Declination (J2000) (1)
32- 33 I2 arcmin DEm Arcminute of Declination (J2000) (1)
35- 41 F7.4 arcsec DEs Arcsecond of Declination (J2000) (1)
42- 47 F6.3 mag Jmag [12.892/15.366] 2MASS J band magnitude
(Cat. II/246)
49- 54 F6.3 mag Hmag [12.714/15.244] 2MASS H band magnitude
56- 61 F6.3 mag Ksmag [12.579/14.824] 2MASS Ks band magnitude
63- 67 F5.2 mag gmag [16.1]? g band magnitude from SDSS DR12
(Cat. V/147)
68 A1 --- n_gmag [e] Note on gmag (2)
70- 74 F5.2 mag u-g [-0.07]? u-g color index from SDSS DR12
75 A1 --- n_u-g [e] Note on u-g (2)
77- 80 F4.2 mag g-i [0.08]? g-i color index from SDSS DR12
81 A1 --- n_g-i [e] Note on g-i (2)
83- 86 F4.2 mag r-i [0.09]? r-i color index from SDSS DR12
87 A1 --- n_r-i [e] Note on r-i (2)
89- 92 F4.2 mag i-z [0.08]? i-z color index from SDSS DR12
93 A1 --- n_i-z [e] Note on i-z (2)
95- 98 F4.2 ct/s CR [0.03/0.06] Count rate from the ROSAT Bright
Source Catalog (Voges et al.
1996IAUC.6420....2V 1996IAUC.6420....2V)
100-103 F4.2 ct/s e_CR [0.01/0.02] Uncertainty in CR
105-112 F8.6 d Per [0.154124/0.1604] Orbital period in the high
state (from Table 5 of this paper)
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Note (1): Positions are from Gaia DR2 (Gaia Collaboration et al. Cat. I/345).
They are referred to the ICRS (equivalent to the J2000 equinox).
Note (2): Note as follows:
e = SDSS observed V704 And, but the data were flagged as unreliable.
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Byte-by-byte Description of file: table3.dat table4.dat
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Bytes Format Units Label Explanations
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1- 11 F11.5 d Time Barycentric Julian Date of mid-integration
(BJD-2400000)
13- 16 I4 km/s RV [-176/164] Barycentric radial velocity of Hα
18- 19 I2 km/s e_RV [2/45] Counting-statistics uncertainty in RV
21 A1 --- State [HLM] Photometric state (H=high, M=medium, L=low)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine pouvreau [CDS] 10-Apr-2019