Detailed Investigation of a W UMa Contact Binary with an Ultralow Mass Ratio and a Third-Body as a Potential Merger Candidate

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Poro, Atila, Paki, Ehsan, Alicavus, Fahri, Michel, Raul
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911350016442368
author Poro, Atila
Paki, Ehsan
Alicavus, Fahri
Michel, Raul
author_facet Poro, Atila
Paki, Ehsan
Alicavus, Fahri
Michel, Raul
contents The lower limit of the mass ratio in contact binaries remains uncertain, with observations suggesting systems exist below theoretical predictions. The stability of such very low mass ratio systems is still debated. Based on our review of systems within the mass ratio cutoff range, we reanalyzed TYC 3801-1529-1 and found it to have the lowest known mass ratio, q=0.024_{-(1)}^{+(2)}, among analyzed contact binaries. The reanalysis of this target was carried out using the BSN application and the MCMC method. We then compared our light curve solution obtained from TESS observations with the results of a previous study. We studied the period variations of this system and identified a cyclic trend over the past six years. After the third-body contribution has been removed, the system's period variations can be described either by a linear trend with a negative slope or by a quadratic trend with a downward curvature. These results indicate that it is still not possible to definitively determine whether the orbital period is increasing or decreasing, underscoring the importance of future observations. By considering the challenges of detecting the faint secondary in extremely low mass ratio systems, we estimated the absolute parameters of the target. Based on our analysis, the secondary component of the binary is likely a brown dwarf, while the third body appears to be a low-mass M-type dwarf. According to our analysis, TYC 3801-1529-1 is dynamically unstable and thus represents a remarkable candidate for a binary merger.
format Preprint
id arxiv_https___arxiv_org_abs_2601_00232
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Detailed Investigation of a W UMa Contact Binary with an Ultralow Mass Ratio and a Third-Body as a Potential Merger Candidate
Poro, Atila
Paki, Ehsan
Alicavus, Fahri
Michel, Raul
Solar and Stellar Astrophysics
The lower limit of the mass ratio in contact binaries remains uncertain, with observations suggesting systems exist below theoretical predictions. The stability of such very low mass ratio systems is still debated. Based on our review of systems within the mass ratio cutoff range, we reanalyzed TYC 3801-1529-1 and found it to have the lowest known mass ratio, q=0.024_{-(1)}^{+(2)}, among analyzed contact binaries. The reanalysis of this target was carried out using the BSN application and the MCMC method. We then compared our light curve solution obtained from TESS observations with the results of a previous study. We studied the period variations of this system and identified a cyclic trend over the past six years. After the third-body contribution has been removed, the system's period variations can be described either by a linear trend with a negative slope or by a quadratic trend with a downward curvature. These results indicate that it is still not possible to definitively determine whether the orbital period is increasing or decreasing, underscoring the importance of future observations. By considering the challenges of detecting the faint secondary in extremely low mass ratio systems, we estimated the absolute parameters of the target. Based on our analysis, the secondary component of the binary is likely a brown dwarf, while the third body appears to be a low-mass M-type dwarf. According to our analysis, TYC 3801-1529-1 is dynamically unstable and thus represents a remarkable candidate for a binary merger.
title Detailed Investigation of a W UMa Contact Binary with an Ultralow Mass Ratio and a Third-Body as a Potential Merger Candidate
topic Solar and Stellar Astrophysics
url https://arxiv.org/abs/2601.00232