Spectral and photometric behavior of SU UMa during quiescence and outburst states

Abstract We report the results of spectral and photometric observations of SU UMa. Available spectra from International Ultraviolet Explorer (IUE) and CCD photometry of five nights were used. Some profiles revealing the variations of some spectral lines at different times are presented. There is variation with time for photometric observations and the brightness of SU UMa is changed from 12.9 mag. to 15.6 mag in 5 nights with clear display of burst. The ultraviolet luminosity for emitting region is in the range of (6.9*10 30  erg s −1 ). The mass accretion rate is in the range of (9.8*10 − 13  M ⊙ yr −1 ). The line flux modulations at different times can be explained in terms of the mass transfer instability model (Bath 1973).