# On the orbital period of the magnetic Cataclysmic Variable HS 0922+1333

## TL;DR

This study clarifies the orbital period of the magnetic Cataclysmic Variable HS 0922+1333, confirming it as a synchronous system with a 4.04-hour period through extensive spectroscopic and photometric observations.

## Contribution

The paper provides the first definitive measurement of the orbital period of HS 0922+1333, resolving previous ambiguities caused by emission line components.

## Key findings

- HS 0922+1333 has an orbital and spin period of 4.04 hours.
- Previous observations were confused by high velocity emission components.
- The system is confirmed to be a synchronous polar.

## Abstract

Context: The object HS 0922+1333 was visited briefly in 2002 in a mini survey of low accretion rate polars (LARPs) in order to test if they undergo high luminosity states similar to ordinary polars. On the basis of that short observation the suspicion arose that the object might be an asynchronous polar (Tovmassian et al. 2004). The disparity between the presumed orbital and spin period appeared to be quite unusual. Aims: We performed follow-up observations of the object to resolve the problem. Methods: New simultaneous spectroscopic and photometric observations spanning several years allowed measurements of radial velocities of emission and absorption lines from the secondary star and brightness variations due to synchrotron emission from the primary. Results: New observations show that the object is actually synchronous and its orbital and spin period are equal to 4.04 hours. Conclusions: We identify the source of confusion of previous observations to be a high velocity component of emission line arousing from the stream of matter leaving L1 point.