AAS 201st Meeting, January, 2003
Session 40. Normal and Dwarf Novae
Poster, Tuesday, January 7, 2003, 9:20am-6:30pm, Exhibit Hall AB

## [40.04] Evidence of an accreting white dwarf during the 2002 optical outburst of the old nova GK Per(2001)

A. Bianchini (WIRO, Dept. of Physics & Astronomy, University of Wyoming, Laramie WY), C. Garcia (Concordia College, Moorhead MN), R. Canterna (WIRO, Dept. of Physics & Astronomy, University of Wyoming, Laramie WY)

The old nova GK Per (1901) is known to be an intermediate polar and to present dwarf nova-like optical outbursts. We have obtained two VHP holographic spectra (\lambda\lambda4500,8000, 2 Å resolution) of the nova with the 1.82 m telescope of the Asiago Observatory, during the rise and at the the light maximum of its 2002 optical outburst. The first spectrum shows a rather flat continuum while that of light maximum suggests a distribution law F\lambda \propto \lambda-1.3, which is much less steeper that that of a typical accretion disk ( \propto \lambda -2.3). The intensities of HI and HeI lines increased by a factor 3.5, while those of HeII became 4.5 times as much stronger. However, both the equivalent widths and line widths appeared roughly the same or slightly smaller. At light maximum, at the base of the H\alpha emission profile, we can see an asymmetric broad emission component that we interpret as the blue- and red-shifted emission from the rapidly rotating accretion curtains. We conclude that during the optical outburst, GK Per did not develope a standard'' accretion disc and that accretion onto the the magnetic WD reached a maximum at light maximum.

This work has been supported by NSF REU site grant AST 0097356.

Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.