Spectroscopy and Component Masses of the Eclipsing Dwarf Nova HS0907+1902

Abstract

HS0907+1902 was recently discovered to be one of a handful of deeply eclipsing dwarf novae with periods longward of the 2 -- 3 hr `gap'. This paper presents orbit-resolved spectra and time series photometry of an eclipse. The apparent velocity amplitude of the M-dwarf secondary is K_2 = 297 +- 15 km/s. The phase of the radial velocities of the H-alpha emission line wings agrees accurately (for once) with the phase of the white-dwarf motion deduced from the eclipse, and an estimate of the emission-line velocity amplitude yields K1 = 115 +- 7 km/s. The eclipse width is delta-phi = 0.060 +- 0.005. At face value, these measurements yield mass estimates of M1 = 0.99 +- 0.12 solar masses for the white dwarf and M2 = 0.38 +- 0.06 solar masses for the secondary. The eclipse width and nominal mass ratio constrain the binary inclination to be 77.3 +- 0.9 degree. The influence of systematic uncertainties on these values is discussed; the conclusion that the white dwarf is somewhat more massive than typical field white dwarfs appears to be robust. The H-alpha emission line profile out of eclipse is only slightly double-peaked, but the line shows a strong rotational disturbance in eclipse. Models of the line profile through eclipse using a flat, Keplerian disk do not give a good quantitative match to the observations.

One tex file, and 7 figures Replaced because of typo in abstract (should be M2=0.38+-0.06)

References in corpus (3)

• RVSAO 2.0: Digital Redshifts and Radial Velocities
• LS Peg: A Low-Inclination SW Sextantis-Type Cataclysmic Binary with High-Velocity Balmer Emission Line Wings
• On the nature of SW Sex

Cited by in corpus (18)

• Post-common-envelope binaries from SDSS. XI: The white dwarf mass distributions of CVs and pre-CVs
• Superhumps in Cataclysmic Binaries. XXV. q_crit, epsilon(q), and Mass-Radius
• Adiabatic Mass Loss in Binary Stars. II. From Zero-Age Main Sequence to the Base of the Giant Branch
• Variable Star Network: World Center for Transient Object Astronomy and Variable Stars
• The evolutionary status of Cataclysmic Variables: Eclipse modelling of 15 systems
• VLT/FORS spectroscopy of faint cataclysmic variables discovered by the Sloan Digital Sky Survey
• CSS100603:112253-111037: A helium-rich dwarf nova with a 65 minute orbital period
• A Far-Ultraviolet Survey of 47 Tucanae.II The Long-Period Cataclysmic Variable AKO 9
• ULTRACAM photometry of the eclipsing cataclysmic variables GY Cnc, IR Com and HT Cas
• Hunting For Eclipses: High Speed Observations of Cataclysmic Variables
• Orbital periods of cataclysmic variables identified by the SDSS. VI. The 4.5-hr period eclipsing system SDSS J100658.40+233724.4
• Orbital periods of cataclysmic variables identified by the SDSS. V. VLT, NTT and Magellan observations of nine equatorial systems
• Constraining modified gravity from tidal phenomena in binary stars
• Outburst Photometry of the Eclipsing Dwarf Nova GY Cancri
• HS 2325+8205 - an ideal laboratory for accretion disk physics
• A stellar constraint on Eddington-inspired Born-Infeld gravity from cataclysmic variable binaries
• Robust Models for Phase Shifts in Accreting Binary Stars
• Orbital periods of cataclysmic variables identified by the SDSS. VIII. A slingshot prominence in SDSS J003941.06+005427.5?