J/A+A/507/929 Light curves of SDSS J100658.40+233724.4 (Southworth+, 2009) ================================================================================ Orbital periods of cataclysmic variables identified by the SDSS. VI. The 4.5-hr period eclipsing system SDSS J100658.40+233724. Southworth J., Hickman R.D.G., Marsh T.R., Rebassa-Mansergas A., Gansicke B.T., Copperwheat C.M., Rodriguez-Gil P. =2009A&A...507..929S ================================================================================ ADC_Keywords: Binaries, cataclysmic ; Photometry, CCD ; Spectroscopy Keywords: stars: dwarf novae - stars: novae, cataclysmic variables - stars: binaries: eclipsing - stars: binaries: spectroscopic - stars: white dwarfs - stars: individual: SDSS J100658.40+233724 Abstract: We present time-resolved spectroscopy and photometry of SDSS J100658.40+233724.4, which we have discovered to be an eclipsing cataclysmic variable with an orbital period of 0.18591324 days (267.71507min). The observed velocity amplitude of the secondary star is 276+/-7km/s, which an irradiation correction reduces to 258+/-12km/s. Doppler tomography of emission lines from the infrared calcium triplet supports this measurement. We have modelled the light curve using the LCURVE code and Markov Chain Monte Carlo simulations, finding a mass ratio of 0.51+/-0.08. From the velocity amplitude and the light curve analysis we find the mass of the white dwarf to be 0.78+/-0.12M_{sun}_ and the masses and radii of the secondary star to be 0.40+/-0.10M_{sun}_ and 0.466+/-0.036R_{sun}_, respectively. The secondary component is less dense than a normal main sequence star but its properties are in good agreement with the expected values for a CV of this orbital period. By modelling the spectral energy distribution of the system we find a distance of 676+/-40pc and estimate a white dwarf effective temperature of 16500+/-2000K. Description: We present the discovery and follow-up observations of eclipses of the cataclysmic variable star SDSS J100658.40+233724.4, fom which we determine the orbital period and the masses and radii of the two stellar components. Time-resolved optical spectroscopic observations covering the full orbital period were obtained on three consecutive nights. Time-resolved photometry of four eclipses was obtained between 2008 February and December. Objects: --------------------------------------------------------------------------- RA (2000) DE Designation(s) --------------------------------------------------------------------------- 10 06 58.4 +23 37 24 SDSS J100658.40+233724.4 = SDSS J100658.41+233724.4 --------------------------------------------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file caha.dat 29 784 White-light photometry from Calar Alto 2.2m not.dat 29 559 Wide-V-filter photometry from the NOT 2.5m obs.dat 34 157 Spectroscopic observations sp/* . 157 FITS files of red and blue spectra -------------------------------------------------------------------------------- See also: http://www.sdss.org : SDSS Home Page J/MNRAS/373/687 : Spectra of 5 faint cataclysmic variables (Southworth+, 2006) Byte-by-byte Description of file: caha.dat not.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 14 F14.6 d HJD Heliocentric Julian Date of exposure midpoint 17- 22 F6.3 mag mag Apparent magnitude of SDSS J100658.40+233724.4 25- 29 F5.3 mag e_mag Measurement error in 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- 22 A4 --- Band [red blue] Red or blue 24- 34 A11 --- FileName Name of the fits file in sp subdirectory -------------------------------------------------------------------------------- Acknowledgements: John Southworth, jkt(at)astro.keele.ac.uk References: Southworth et al., Paper I 2006MNRAS.373..687S, Cat. Southworth et al., Paper II 2007MNRAS.382.1145S Dillon et al., Paper III 2008MNRAS.386.1568D Southworth et al., Paper IV 2008MNRAS.388..709S Southworth et al., Paper V 2008MNRAS.391..591S ================================================================================ (End) John Southworth [Warwick, UK], Patricia Vannier [CDS] 18-Sep-2009