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Ultraviolet continuum variability and visual flickering in the peculiar object MWC 560High-speed U-band photometry of the peculiar emission object MWC 560 obtained with the ground-based instrumentation, and V-band photometry obtained with the International Ultraviolet Explorer-Fine Error Sensor indicates irregular brightness variations are quasi-periodic. Multiple peaks of relative brightness power indicate statistically significant quasi periods existing in a range of 3-35 minutes, that are superposed on slower hourly varying components. We present a preliminary model that explains the minute and hourly time-scale variations in MWC 560 in terms of a velocity-shear instability that arises because a white dwarf magnetosphere impinges on an accretion disk. We also find evidence for Fe II multiplet pseudocontinuum absorption opacity in far-UV spectra of CH Cygni which is also present in MWC 560. Both CH Cyg and MWC 560 may be in an evolutionary stage that is characterized by strong UV continuum opacity which changes significantly during outburst, occurring before they permanently enter the symbiotic nebular emission phase.
Document ID
19930054484
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Michalitsianos, A. G. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Perez, M. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Shore, S. N. (Computer Sciences Corp.; NASA, Goddard Space Flight Center Greenbelt, MD, United States)
Maran, S. P. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Karovska, M. (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Sonneborn, G. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Webb, J. R. (Florida International Univ. Miami, United States)
Barnes, Thomas G., III (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Frueh, Marian L. (McDonald Observatory Austin, TX, United States)
Oliversen, R. J. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 16, 2013
Publication Date
June 1, 1993
Publication Information
Publication: Astrophysical Journal, Part 2 - Letters
Volume: 409
Issue: 2
ISSN: 0004-637X
Subject Category
ASTROPHYSICS
Distribution Limits
Public
Copyright
Other