Two-Color VR CCD Photometry of Old Nova V603 Aquilae

Abstract

Results of 6 nights of CCD VR photometry of the nova-like variable V603 Aquilae (Nova Aquilae 1918) obtained at the Mallorcian 35-cm telescope in July 2004 are reported. The ephemeris for the superhump maximum is Max.HJD=2453213.60546(96) +0.14813(10)E. The waves with 3.9d, 1.4d, 0.135d are statistically significant, which may be interpreted as the negative superhump-orbital, the beat periods (negative superhump - positive superhump) and the negative superhump with low amplitude, respectively. Another possible time-scale is 0.8d, which has no coincidence with the beat periods. Quasi-periodic oscillations with an effective period of 18 minutes have been detected, which are close to 15.6 minutes reported by some authors. Their effective semi-amplitudes are 0.045m and 0.051m for V and R, respectively. This corresponds to the 0.12 mag excess in the color index V-R as compared with the mean color, which can be understood as the pulsed emission in the hotter inner parts of the accretion disk, similar to that observed in TT Ari and MV Lyr.

Keywords

• variable stars
• cataclysmic variables
• novae
• CCD photometry
• V603 Aql.