Investigating orbital periodicity in HS 2231+2441 with extended observations

We present a comprehensive photometric study of the HW Vir-type eclipsing binary HS 2231 + 2441 based on new observations from 2014 to 2024. Our work combines high-precision ground-based data from the TUG T100 and ATA50 telescopes in Turkey with space-based TESS observations and archival measurements from the AAVSO and BAAVSS databases. The light curves obtained from the TUG T100 and ATA50 telescopes show an average rms of 0.009 mag, demonstrating the high reliability of our eclipse timing and light curve models. A total of 1394 mid-eclipse times were collected, allowing us to extend the O C diagram to a 20-year period and derive an updated linear ephemeris with an orbital period of 0.1105878581 days. Attempts to fit a quadratic ephemeris did not improve the fit, suggesting that any period variation is extremely subtle or absent. An extensive periodicity search was performed using both the Lomb Scargle periodogram and the Weighted Wavelet Z-transform with a one percent false alarm threshold. Although a transient signal was detected over a limited cycle range, it was not consistent across the data set and has not been independently confirmed. The overall scatter in the O C diagram, measured at 35.13 s for the full dataset and reduced to 19.90 and 13.86 sin refined subsets, likely reflects both the intrinsic dynamics of the system and the limitations of current observational techniques. This study not only improves the precision of eclipse timing for HS 2231 + 2441, but also underscores the critical importance of long-term, high-quality observations to probe subtle dynamical processes in compact binary systems. (c) 2025 COSPAR. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Journal

ADVANCES IN SPACE RESEARCH

Year

2025

Volume

76

Issue

2

Pages

1204-1212

ISSN

0273-1177

eISSN

1879-1948

DOI

10.1016/j.asr.2025.05.009

WoS UID

WOS:001523513600030