J/A+A/524/A86 Light curves of SDSS J003941.06+005427.5 (Southworth+, 2010)
Orbital periods of cataclysmic variables identified by the SDSS.
VIII. A slingshot prominence in SDSS J003941.06+005427.5?
Southworth J., Marsh T.R., Gansicke B.T., Steeghs D., Copperwheat C.M.
<Astron. Astrophys. 524, A86 (2010)>
=2010A&A...524A..86S 2010A&A...524A..86S
ADC_Keywords: Binaries, cataclysmic ; Photometry, CCD ; Spectroscopy
Keywords: stars: dwarf novae - binaries: spectroscopic -
novae, cataclysmic variables
Abstract:
We present VLT spectroscopy and NTT photometry of the faint
cataclysmic binary SDSS J003941.06+005427.5. This object shows
triple-peaked Hα emission with all three peaks variable in both
strength and velocity. We measure an orbital period of
91.395±0.093min from the velocity variations of the wings of the
Halpha emission line. Using the GALEX and SDSS photometry of this
object, we determine a white dwarf temperature of 15000K and a very
late (≥L2) spectral type for the companion star. These measurements,
plus the relatively long orbital period, suggest that SDSS
J003941.06+005427.5 may be a post-bounce cataclysmic variable. Doppler
maps of the Hα and HeI 6678Å emission features show an
accretion disc with a non-uniform brightness and departures from
Keplerian flow. The third emission peak is detected only in Hα
and at a relatively low velocity amplitude of 202±3km/s. We are
unable to explain this emission as arising from either the white
dwarf, the secondary star, or the accretion disc. We tentatively
attribute this mysterious central peak to a coronal loop anchored at
the secondary star. If confirmed, this would be the first example of a
slingshot prominence in a CV with a low mass-transfer rate and/or a
fully convective secondary star.
Description:
Long-slit spectroscopy (29 spectra obtained over two nights) and
differential photometry (167 datapoints obtained over two nights) are
presented for the cataclysmic variable SDSS J003941.06+005427.5.
Objects:
----------------------------------------------------------------------------
RA (2000) DE Designation(s)
----------------------------------------------------------------------------
00 39 41.1 +00 54 28 SDSS J003941.06+005427.5 = SDSS J003941.06+005427.5
----------------------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
lc.dat 28 166 Photometry of SDSS J003941.06+005427.5
obs.dat 33 29 Spectroscopic observations
sp/* . 29 FITS files with spectra
--------------------------------------------------------------------------------
See also:
J/MNRAS/373/687 : Spectra of 5 cataclysmic variables (Southworth+, 2006)
J/A+A/507/929 : Light curves of SDSS J100658.40+233724.4 (Southworth+, 2009)
J/A+A/510/A100 : Four new SDSS eclipsing systems (Southworth+, 2010)
Byte-by-byte Description of file: lc.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.5 d HJD Heliocentric Julian Date (UTC timescale) of
the exposure midpoint
16- 21 F6.3 mag mag Apparent magnitude of SDSS J003941.06+005427.5
24- 28 F5.3 mag e_mag Measurement error in the apparent magnitude
--------------------------------------------------------------------------------
Byte-by-byte Description of file: obs.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 F17.9 d HJD Heliocentric Julian Date of observation
19- 33 A15 --- FileName Name of the fits file in sp subdirectory
--------------------------------------------------------------------------------
Acknowledgements:
John Southworth, jkt(at)astro.keele.ac.uk
References:
Southworth et al., Paper I 2007MNRAS.378..635S 2007MNRAS.378..635S
Southworth et al., Paper II 2007MNRAS.382.1145S 2007MNRAS.382.1145S
Dillon et al., Paper III 2008MNRAS.386.1568D 2008MNRAS.386.1568D
Southworth et al., Paper IV 2008MNRAS.388..709S 2008MNRAS.388..709S
Southworth et al., Paper V 2008MNRAS.391..591S 2008MNRAS.391..591S
Southworth et al., Paper VI 2009A&A...507..929S 2009A&A...507..929S, Cat. J/A+A/507/929
Southworth et al., Paper VII 2010A&A...510A.100S 2010A&A...510A.100S, Cat. J/A+A/510/A100
(End) Patricia Vannier [CDS] 28-Sep-2010