RACE-OC Project: Rotation and variability in the epsilon Chamaeleontis, Octans, and Argus stellar associations

TL;DR

This study measures the rotation periods of young stars in several stellar associations to better understand how stellar angular momentum evolves during early stellar development.

Contribution

It extends previous research by providing rotation periods for stars in three additional young associations, covering ages from 6 to 40 million years.

Findings

Rotation periods for 241 stars were determined.

The data enhances understanding of stellar angular momentum evolution.

The study completes rotational analysis for known young associations in the solar neighborhood.

Abstract

We aim at determining the rotational and magnetic-related activity properties of stars at different stages of evolution. We focus our attention primarily on members of young stellar associations of known ages. Specifically, we extend our previous analysis in Paper I (Messina et al. 2010, A&A 520, A15) to 3 additional young stellar associations beyond 100 pc and with ages in the range 6-40 Myr: epsilon Chamaeleontis (~6 Myr), Octans (~20 Myr), and Argus (~40 Myr). Additional rotational data of eta Chamaeleontis and IC2391 clusters are also considered. Rotational periods were determined from photometric time-series data obtained by the All Sky Automated Survey (ASAS) and the Wide Angle Search for Planets (SuperWASP) archives. With the present study we have completed the analysis of the rotational properties of the late-type members of all known young loose associations in the solar neighborhood. Considering also the results of Paper I, we have derived the rotation periods of 241 targets: 171 confirmed, 44 likely, 26 uncertain. The period of the remaining 50 stars known to be part of loose associations still remains unknown. This rotation period catalogue, and specifically the new information presented in this paper at ~6, 20, and 40 Myr, contributes significantly to a better observational description of the angular momentum evolution of young stars.