Nova V4743 Sagittarii 2002: An Intermediate Polar Candidate

We present the results of 11 nights of CCD unfiltered photometry of V4743 Sgr (Nova Sgr 2002 No. 3) from 2003 and 2005. We find two periods of 0.2799 days (≈6.7 hr) and 0.01642 days (≈24 minutes) in the 2005 data. The long period is also present in the 2003 data, but only weak evidence of the shorter period is found in this year. The 24 minute period is somewhat longer than the 22 minute period that was detected from X-ray observations. We suggest that the 6.7 hr periodicity represents the orbital period of the underlying binary system and that the 24 minute period is the beat periodicity between the orbital period and the X-ray period, which is presumably the spin period of the white dwarf. Thus, V4743 Sgr should be classified as an intermediate polar (DQ Her star). About 6 months after the nova outburst, the optical light curve of V4743 Sgr seemed to show quasi-periodic oscillations, which are typical of the transient phase in classical novae. Therefore, our results support the previous suggestion that the transition phase in novae may be related to intermediate polars.