Properties of the quasi-coherent oscillations in the extreme ultraviolet flux of the dwarf nova SS Cygni are described. Rapid periodic oscillations are observed in the optical and soft X-ray flux of high accretion rate cataclysmic variables (CVs; nova-like variables and dwarf novae in outburst). These so-called `dwarf nova oscillations` (DNOS) have high coherence (Q {approx} 10{sup 4}-10{sup 6}), periods of {approx} 10-30 s, and amplitudes of @ 10-30% in soft X-rays and @ 0.5% in the optical. DNOs have never been detected in dwarf novae in quiescence, despite extensive searches; they appear on the rising branch of the dwarf nova, ...
continued below
Publisher Info:
Lawrence Livermore National Lab., CA (United States)
Place of Publication:
California
Provided By
UNT Libraries Government Documents Department
Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.
Descriptive information to help identify this article.
Follow the links below to find similar items on the Digital Library.
Description
Properties of the quasi-coherent oscillations in the extreme ultraviolet flux of the dwarf nova SS Cygni are described. Rapid periodic oscillations are observed in the optical and soft X-ray flux of high accretion rate cataclysmic variables (CVs; nova-like variables and dwarf novae in outburst). These so-called `dwarf nova oscillations` (DNOS) have high coherence (Q {approx} 10{sup 4}-10{sup 6}), periods of {approx} 10-30 s, and amplitudes of @ 10-30% in soft X-rays and @ 0.5% in the optical. DNOs have never been detected in dwarf novae in quiescence, despite extensive searches; they appear on the rising branch of the dwarf nova, outburst, typically persist through maximum, and disappear on the declining branch of the outburst. The period of the oscillation also correlates with outburst state, decreasing on the rising branch and increasing on the declining branch. 2048 The dwarf nova SS Cygni routinely exhibits DNOs during outburst. Optical oscillations have been detected at various times with periods ranging from 7.3 s to 10.9 s. At soft X-ray energies, oscillations have been detected in {ital HEAO 1} LED 1 data at periods of @ 9 s and 11 s and in EXOSAT LE data at periods between 7.4 s and 10.4 s. Here, we describe the properties of the oscillations in the extreme ultraviolet (EUV) flux detected with the {ital Extreme Ultraviolet Explorer} (EUVE) Deep Survey (DS) photometer and Short Wavelength (SW) spectrometer during target-of-opportunity observations of SS Cyg in out- burst in 1993 August and 1994 June/July.
This article is part of the following collection of related materials.
Office of Scientific & Technical Information Technical Reports
Reports, articles and other documents harvested from the Office of Scientific and Technical Information.
Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.
Mauche, C.W.The quasi-coherent oscillations of SS Cygni,
article,
August 1, 1996;
California.
(digital.library.unt.edu/ark:/67531/metadc679275/:
accessed February 17, 2019),
University of North Texas Libraries, Digital Library, digital.library.unt.edu;
crediting UNT Libraries Government Documents Department.