# A photometric study of the high-mass-ratio contact binary AV Puppis

## TL;DR

This study presents multi-color photometric analysis of AV Puppis, revealing it as a high-mass-ratio contact binary with increasing orbital period due to mass transfer, using Wilson-Devinney modeling.

## Contribution

It provides the first detailed photometric solution and orbital period analysis of AV Puppis, highlighting its peculiar high mass ratio and period increase.

## Key findings

- AV Puppis is a high-mass-ratio contact binary with q=0.896.
- The orbital period of AV Puppis is increasing at 4.83×10⁻⁷ days/year.
- The period increase is caused by mass transfer from the less to the more massive component.

## Abstract

The multi-color photometric light curves for a contact binary AV Puppis (AV Pup) in $VR_cI_c$ bandpasses are presented, and they are analyzed by using of the 2013 version of the Wilson-Devinney (W-D) code. The solutions suggest that AV Pup is a peculiar A-subtype W UMa contact binary with a high mass ratio ($q=m_2/m_1= 0.896$) and a fill-out factor ($f=10\%$). Combining with our newly determined times of minimum with those collected from literatures, the orbital period changes of this system are investigated. The $O-C$ analysis shows that the orbital period of AV Pup is increasing at a rate of $\mathrm{d}P/\mathrm{d}t=4.83 \times 10^{-7} \ \mathrm{days \ yr^{-1}}$, which can be explained by mass transfer from the less massive component to the more massive one.