Accession Number : ADA514123


Title :   The White Dwarf in EM Cygni: Beyond the Veil


Descriptive Note : Journal article


Corporate Author : VILLANOVA UNIV PA DEPT OF ASTRONOMY AND ASTROPHYSICS


Personal Author(s) : Godon, Patrick ; Sion, Edward M. ; Barrett, Paul E. ; Linnell, Albert P.


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA514123


Report Date : 10 JUL 2009


Pagination or Media Count : 14


Abstract : Dwarf novae (DNe) are a class of nonmagnetic cataclysmic variables (CVs) in which a white dwarf (WD) accretes matter from a main-sequence star (the secondary) filling its Roche lobe by means of an accretion disk. DN systems are characterized mainly by their brightness variations, due to a periodic change in the accretion rate. Ongoing accretion at a low rate (quiescence) is interrupted every few weeks to months by intense accretion (outburst) of days to weeks which increases the luminosity of the system (Hack & La Dous 1993; Warner 1995). This outburst is believed to be due to an instability in the disk (the disk instability model (DIM; Cannizzo 1998)), and it is known as a dwarf nova accretion event (or dwarf nova outburst).


Descriptors :   *DWARF STARS , REPRINTS , FLUX(RATE) , NOVAE , DISKS , FAR ULTRAVIOLET RADIATION , ORBITS , ULTRAVIOLET SPECTROSCOPY


Subject Categories : ASTRONOMY


Distribution Statement : APPROVED FOR PUBLIC RELEASE