Investigating AM Her Cataclysmic Variables with OPTIMA

TL;DR

This paper presents high-time resolution photometry observations of two magnetic cataclysmic variables, HU Aqr and DQ Her, revealing orbital variations that suggest the presence of a giant planet or distant companion.

Contribution

It reports new OPTIMA observations of CVs, confirming orbital variations consistent with planetary or sub-stellar companions, advancing understanding of binary system dynamics.

Findings

Orbital variations in HU Aqr suggest a Jupiter-like planet.

High-time resolution photometry enables detection of subtle orbital changes.

Observations support the existence of a distant companion in the system.

Abstract

We focus on short--period eclipsing binaries that belong to a class of Cataclysmic Variables (CVs). They are known as polars and intermediate polars, closely resembling their prototype AM Herculis. These binaries consist of a red dwarf and a strongly magnetic white dwarf, having orbital periods of only a few hours. Monitoring eclipses of these typically faint sources demands high-time resolution photometry. We describe the very recent results obtained for two CVs, HU Aqr and DQ Her, which were observed with the Optical Pulsar Timing Analyzer (OPTIMA). The new observations of HU Aqr confirm that the O--C (Observed minus Calculated) diagrams exhibit variations known for this binary which can be explained by a single, massive Jupiter--like planet, possibly accompanied by a very distant companion.