AAS 201st Meeting, January, 2003
Session 120. Cataclysmic Variables
Poster, Thursday, January 9, 2003, 9:20am-4:00pm, Exhibit Hall AB

## [120.02U] An Observation of XY Arietis with Chandra

A.D. Salinas (University of Texas at Austin), Eric M. Schlegel (Harvard-Smithsonian CfA)

Chandra has observed the intermediate polar cataclysmic variable (CV), XY Arietis (H0253+193), in two observations separated by approximately a month. XY Ari is a fully eclipsing CV (80\circ \circ) with a spin period, \omega, of 206.298 sec and an orbital period, \Omega, of 6.02 hours. The two separate continuous observations of this CV allow for the study of phase resolved spectra for this system. Spectra have been extracted for certain phase ranges in both observations in the spin folded light curves. The iron K\alpha emission lines have been studied in this system and show a change in the relative strengths of the 6.4 keV, 6.7 keV, and 7.0 keV lines as well as a change in the equivalent widths of certain iron emission lines from phase to phase. The 6.4 keV fluorescent line is only visible for 60% of the first observation, and only 20% in the second observation (to the 95% confidence level). Previous studies of this system assumed that the presence of the iron emission lines do not change significantly over the spin period. This observation of XY Ari shows that there are changes in the strengths of the lines over a single observation. Changes also occur in the percentage of broad iron lines, suggesting changes in the system itself from observation to observation.

This work was supported in part by NSF grant AST-9731923 to the SAO Summer Intern program.