Binary Stars among Cataclysmic Variables. I. U Geminorum Stars (dwarf Novae).

1962 ◽  
Vol 135 ◽  
pp. 408 ◽  
Author(s):  
Robert P. Kraft
Keyword(s):  
Binary Stars ◽  
Cataclysmic Variables ◽  
Dwarf Novae

scholarly journals Ultraviolet Observations of Cataclysmic Variables

1987 ◽  
Vol 93 ◽  
pp. 205-205 ◽  
Author(s):  
F. Verbunt
Keyword(s):  
Orbital Period ◽  
Cataclysmic Variables ◽  
Type Systems ◽  
Terminal Velocity ◽  
Dwarf Novae ◽  
Preliminary Results ◽  
System Type ◽  
International Ultraviolet Explorer ◽  
Flux Level ◽  
Ultraviolet Observations

AbstractThe preliminary results of the analysis of more than 1000 spectra of cataclysmic variables in the archive of the International Ultraviolet Explorer were presented at the meeting. To characterize the slope of the spectra I use F = log(f1460Å/f2880Å). For most spectra F lies between 0.2 and 0.7. No correlation of F with orbital period, inclination, system type or (for dwarf novae) length of the interoutburst interval are found, apart from somewhat lower values of F for DQ Her type systems. Out of 16 dwarf novae for which spectra both at outburst maximum and minimum are available 11 show no large difference in F between maximum and minimum, and in 5 F declines with the flux level. Out of 6 dwarf novae 5 show very red spectra during the rise to maximum, and 1 shows slopes during rise similar to those during decline.In the ultraviolet resonance lines, due to a wind from the disc, no correlation is found between inclination and terminal velocity.

scholarly journals A Fuse Survey of Disk-Accreting Cataclysmic Variables

2004 ◽  
Vol 194 ◽  
pp. 251-251
Author(s):  
C. S. Froning ◽  
K. S. Long ◽  
P. Szkody ◽  
B. T. Gänsicke
Keyword(s):  
Cataclysmic Variables ◽  
Dwarf Novae ◽  
X Ray ◽  
Intermediate Polars ◽  
Far Ultraviolet ◽  
X Ray Binaries ◽  
Initial Results

We present initial results of a survey of the FUV spectra of disk-accreting cataclysmic variables obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE).FUSE covers the 905 - 1188 Å range at spectral resolutions ≃0.1 Å. To date, FUSE has observed more than 65 cataclysmic variables (CVs). Publicly-available data include observations of 11 dwarf novae (DN), 15 non-magnetic novalikes (NLs), 7 intermediate polars and DQ Her stars, at least 15 polars, and 4 super-soft X-ray binaries.

scholarly journals Physical Interpretation of Dwarf Nova Primary Effective Temperatures

2004 ◽  
Vol 194 ◽  
pp. 192-193
Author(s):  
Dean M. Townsley ◽  
Lars Bildsten
Keyword(s):  
Gravitational Radiation ◽  
Accretion Rate ◽  
Thermal State ◽  
Cataclysmic Variables ◽  
Theoretical Work ◽  
Dwarf Novae ◽  
Radiation Losses ◽  
Accretion Rates ◽  
The Masses ◽  
The Impact

AbstractWe have undertaken a theoretical study of the impact of the accumulating envelopes on the thermal state of the underlying white dwarf (WD). This has allowed us to find the equilibrium WD core temperatures, the classical nova ignition masses and the thermal luminosities for WDs accreting at rates of 10–11 – 10–8M⊙ yr–1. These accretion rates are most, appropriate to WDs in cataclysmic variables (CVs) of (Porb ≲ 7 hr), many of which accrete sporadically as Dwarf Novae. Over twenty Dwarf Novae have been observed in quiescence, when the accretion rate is low and the WD photosphere is detected and Teff measured. Comparing our theoretical work to these observations allows us to constrain the WD mass and the time averaged accretion rate, ⟨Ṁ⟩. If ⟨Ṁ⟩ is that given by gravitational radiation losses alone, then the WD masses are > 0.8 M⊙. An alternative conclusion is that the masses are closer to 0.6M⊙ and ⟨Ṁ⟩ is 3-4 times larger than that expected from gravitational radiation losses.

scholarly journals Pulsating white dwarfs in cataclysmic variables: The marriage of ZZ Cet and dwarf nova

2004 ◽  
Vol 193 ◽  
pp. 382-386 ◽  
Author(s):  
Brian Warner ◽  
Patrick A. Woudt
Keyword(s):  
White Dwarf ◽  
Large Amplitude ◽  
White Dwarfs ◽  
Cataclysmic Variables ◽  
Sloan Digital Sky Survey ◽  
Dwarf Novae ◽  
Dwarf Nova ◽  
Sky Survey

AbstractThere are now four dwarf novae known with white dwarf primaries that show large amplitude non-radial oscillations of the kind seen in ZZ Cet stars. We compare the properties of these stars and point out that by the end of the Sloan Digital Sky Survey more than 30 should be known.

scholarly journals Winds from Disks

1990 ◽  
Vol 122 ◽  
pp. 228-235
Author(s):  
J.E. Drew
Keyword(s):  
Magnetic Field ◽  
Numerical Modelling ◽  
Mass Loss ◽  
Weak Magnetic Field ◽  
Cataclysmic Variables ◽  
Dwarf Novae ◽  
Loss Mechanism ◽  
Fundamental Cause ◽  
Magnetic Cataclysmic Variables ◽  
Thermonuclear Runaway

The disks referred to in the title of this paper are specifically those present in cataclysmic variables in which the accreting white dwarf has a relatively weak magnetic field (≪ 1 MG). Such systems are classified either as nova-like variables or as dwarf novae, and are of interest here because they are believed to be novae in quiescence (Ritter and Livio discuss this point elsewhere in this volume).This review aims to do two things: i) to summarise what has been learned about the winds associated with non-magnetic cataclysmic variables both from observation and from numerical modelling, and ii) to outline ideas about the nature of the mass loss mechanism. By contrast with the certainty that nova outflows are the consequence of thermonuclear runaway, it shall be seen that the fundamental cause of mass loss from cataclysmic variables remains obscure. An earlier review of this subject is by Cordova and Howarth (1986). Also of interest are some sections of the monograph on dwarf novae and nova-like variables by LaDous (1989).

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