New Photometry and Spectroscopy of DW Cnc

TL;DR

This study presents new photometric and spectroscopic observations of DW Cnc, revealing its spin and orbital modulations post-low state, and suggests the system is partially recovering with some original signals still absent.

Contribution

First detailed post-low state analysis of DW Cnc combining photometry, spectroscopy, and Doppler tomography to understand its recovery process.

Findings

Detected 38 min spin period in photometry

Identified disc structure and hot spot in Doppler maps

Observed partial recovery with missing original signals

Abstract

We present new observations of the cataclysmic variable DW Cancri, after the system recovered from a low state. We performed a power spectrum analysis that reveals a clear signal of the 38 min spin period in our photometric data. Our spectroscopic power spectrum search was consistent with studies performed before the low state, showing the orbital and spin modulations. We also conducted a Doppler Tomography study which exhibits a disc structure and an enhanced emission region, possibly related to a hot spot component. Through a wavelet transform analysis we also found evidence of the 70 min spin-orbit beat period. We interpret these results as indication of a partial recovery of the system. Nonetheless, DW Cnc does not yet show all the original photometric modulations reported in 2004, before experiencing the low state. Namely, these signals are a 38 min spin period, an 86 min orbital period, a 70 min beat period between the latter modulations, and an unresolved 110 min period. Even though our photometry shows a spin cycle modulation and a long 108 min period, it lacks the beat and orbital period signals. Thus, we propose further observations of DW Cancri, to elucidate if the mechanisms giving rise to the signatures observed prior to the low state, require more time to reactivate.