Photometric observations of V597 Pup made in 2008 , 9.1 mag below maximum , 4 months after eruption , showed no certain orbital modulation but exhibited a quintuplet of oscillations centred on a period 261.9 s and uniform splitting at a frequency \sim 2.68 h ^ { -1 } .
One year later the system had fallen in brightness by a further 2.5 mag , showed deep eclipses with a period of 2.6687 h , and the 261.9 s modulation at a reduced amplitude .
There is often power near the ‘ subharmonic ’ at 524 s , showing that the shorter periods observed are actually first harmonics .

V597 Pup is thus an intermediate polar and is in the ‘ orbital period gap ’ .
Furthermore it is the first to show a prominent secondary eclipse , caused by passage of the optically thick disc in front of the irradiated side of the secondary star .