J/MNRAS/494/4110 DW Cnc Hα and HeI RV curves (Segura Montero+, 2020)
New observations of DW Cnc: where is the 38 min signal?
Segura Montero O., Ramirez S.H., Echevarria J.
<Mon. Not. R. Astron. Soc., 494, 4110-4118 (2020)>
=2020MNRAS.494.4110S 2020MNRAS.494.4110S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Binaries, cataclysmic ; Radial velocities
Keywords: stars: dwarf novae - stars: individual: DW Cnc - novae -
cataclysmic variables - white dwarfs
Abstract:
We present extensive radial velocity observations of the intermediate
polar DW Cnc during its 2018-2019 low state. We show that the 86 min
signal associated with the orbital period is strong in our radial
velocity analysis, power spectrum search, and in our Doppler
tomography. However, we find that the velocity modulation associated
with the 70 min beat period and the 38 min spin cycle is
dramatically weaker than that previously observed. We put forward two
interpretations for this change. The first is that a sudden drop into
a low state detected in 2018-2019 caused an episode of low mass
transfer from the companion, thus inhibiting the lighthouse effect
produced by the rebound emission. The second is that this is a
consequence of a rare outburst detected in 2007 by Crawford et al.
(2008, J. Am. Assoc. Var. Star Obs., 36, 60). We find this
post-outburst hypothesis to be less likely. If the first scenario is
correct, we predict that DW Cnc will recover its intermediate polar
characteristics. A new ephemeris is presented by combining Patterson
et al. (2004PASP..116..516P 2004PASP..116..516P) radial velocities with ours.
Description:
Spectra were obtained with the 2.1m telescope of the Observatorio
Astronomico Nacional at San Pedro Martir, using the Boller and Chivens
spectrograph and an e2V CCD detector in the 5400-6600Å range
(resolution ∼1200), on the nights of 2017 October 12 and 2018 January
19 and 21-25.
Objects:
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RA (2000) DE Designation(s)
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07 58 53.04 +16 16 45.2 DW Cnc = V* DW Cnc
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
ha40.dat 20 679 Radial velocities of the Hα emission line
he5876.dat 20 465 Radial velocities of the HeI5876Å emission line
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Byte-by-byte Description of file: ha40.dat he5876.dat
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Bytes Format Units Label Explanations
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1- 11 F11.5 d JD Julian date (JD-2400000)
13- 20 F8.3 km/s RV Radial velocity
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 23-Jul-2020