The eclipsing Intermediate Polar V597 Pup (Nova Puppis 2007)

TL;DR

This study presents photometric observations of V597 Pup, revealing its classification as an intermediate polar within the orbital period gap, with unique eclipsing features and complex oscillation patterns that evolve over time.

Contribution

First detailed analysis of V597 Pup showing its intermediate polar nature, orbital period gap status, and discovery of the first prominent secondary eclipse in such systems.

Findings

Detected a quintuplet of oscillations centered on 261.9 s

Observed deep eclipses with a 2.6687 h period

Identified the first prominent secondary eclipse in an intermediate polar

Abstract

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 ~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.