Open AccessA boundary layer origin for dwarf nova oscillations
Author(s) -
Popham Robert
Publication year - 1999
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1999.02782.x
Subject(s) - physics , dwarf nova , nova (rocket) , astrophysics , white dwarf , boundary layer , astronomy , boundary (topology) , stars , mechanics , aerospace engineering , mathematical analysis , mathematics , engineering
Dwarf nova oscillations (DNOs) have been observed in a number of cataclysmic variables. I propose that these oscillations could be produced by a non‐axisymmetric bulge at the transition between the optically thick disc and the optically thin boundary layer region. This would naturally explain the observed oscillation periods and the dependence of the oscillation amplitude on photon energy. The transition radius moves inward and outward with changing mass accretion rate, which explains the correlation between period and flux, and the time‐scale for period variations. The underlying cause of the non‐axisymmetry that produces the oscillations is not known, so it is not possible to predict the oscillation amplitude from first principles.