Photometric Analysis of TCP J20171288$+$1156589 -- WZ Sge Type Dwarf Nova with Delayed Ordinary Superhumps Emergence

TL;DR

This study analyzes the photometric evolution of the WZ Sge-type dwarf nova TCP J20171288+1156589, revealing an atypical superoutburst with delayed ordinary superhumps and estimating key system parameters.

Contribution

It provides the first detailed photometric analysis of this object, highlighting the unusual delay in superhump emergence and deriving system parameters.

Findings

Early superhumps with period 0.0611 days observed

Ordinary superhumps emerged after ~11 days with period 0.0616 days

System parameters estimated: mass ratio 0.06, distance ~850 pc

Abstract

We present the results of photometric analysis of WZ Sge type dwarf nova TCP J20171288$+$1156589. This object exhibited an outburst with a large amplitude of $>7.9$ magnitudes and was observed for over a month. The photometric evolution of the superoutburst was atypical for WZ Sge-type dwarf novae. Periodogram analisys reveals early superhumps with the most probable period of $0.0611\pm0.0001$ days during the initial decline. After a plateau phase of approximately 11 days, ordinary superhumps (likely stage B) emerged with a period of $0.0616\pm0.0001$ days, corresponding to a superhump excess of $\epsilon=0.008$ correspondingly. This delay in the onset of ordinary superhumps is an unusual feature among WZ Sge stars. We evaluated the main parameters of the system: mass ratio $q=M_{RD}/M_{WD}=0.06\pm0.005$, yielding component masses of $M_{WD}\sim1.0\pm0.15M_{\odot}$ for the white dwarf and $M_{RD}=0.06\pm0.01M_{\odot}$ for the donor. The estimated distance to the system is $\sim850$ pc, and the binary separation is $a=0.67\pm0.03R_{\odot}$.