Spectroscopic binaries among AGB stars from HERMES/Mercator: the case of V Hya

TL;DR

This study investigates spectroscopic binaries among AGB stars using HERMES/Mercator, highlighting V Hya as a binary with disc features, contributing to understanding binary interactions in evolved stars.

Contribution

It presents new evidence of binarity in AGB stars, especially V Hya, using radial velocity monitoring with the HERMES spectrograph, emphasizing the binary nature of RV Tau stars.

Findings

Detected binarity in V Hya and other AGB stars.

V Hya exhibits characteristics of RV Tau binaries with discs.

Confirmed the presence of spectroscopic binaries among AGB stars.

Abstract

We report on our search for spectroscopic binaries among a sample of AGB stars. Observations were carried out in the framework of the monitoring of radial velocities of (candidate) binary stars performed at the Mercator 1.2m telescope, using the HERMES spectrograph. We found evidence for duplicity in UV Cam, TU Tau, BL Ori, VZ Per, T Dra, and V Hya. This short communication focus on V Hya, found to behave like RV Tau of the b subtype, which are binaries surrounded by a disc.