Hunting for Stellar Coronal Mass Ejections

TL;DR

This study investigates the occurrence and detection of stellar coronal mass ejections in young open clusters using spectroscopic observations, aiming to understand their frequency and properties across different stellar ages and types.

Contribution

The paper presents new spectroscopic data from multiple open clusters and archival sources to analyze stellar CME occurrence rates across various ages and spectral types.

Findings

Initial detection of stellar CMEs in young clusters

Correlation between stellar activity and CME frequency

Data suggests higher CME rates in younger, active stars

Abstract

Coronal mass ejections (CMEs) are explosive events that occur basically daily on the Sun. It is thought that these events play a crucial role in the angular momentum and mass loss of late-type stars, and also shape the environment in which planets form and live. Stellar CMEs can be detected in optical spectra in the Balmer lines, especially in Halpha, as blue-shifted extra emission/absorption. To increase the detection probability one can monitor young open clusters, in which the stars are due to their youth still rapid rotators, and thus magnetically active and likely to exhibit a large number of CMEs. Using ESO facilities and the Nordic Optical Telescope we have obtained time series of multi-object spectroscopic observations of late-type stars in six open clusters with ages ranging from 15 Myrs to 300 Myrs. Additionally, we have studied archival data of numerous active stars. These observations will allow us to obtain information on the occurrence rate of CMEs in late-type stars with different ages and spectral types. Here we report on the preliminary outcome of our studies.