V4633 Sgr - a probable second asynchronous polar classical nova

Photometric observations of V4633 Sgr (Nova Sagittarii 1998) during 1998–2005 reveal the presence of a stable photometric periodicity at P1= 180.8 min which is probably the orbital period of the underlying binary system. A second period was present in the light curve of the object for 6 yr. Shortly after the nova eruption it was measured as P2= 185.6 min. It has decreased monotonically in the foll...