Searching for stellar CMEs in the Praesepe and Pleiades clusters

TL;DR

This study used ground-based spectroscopy alongside TESS data to search for stellar CMEs and flares in young clusters, but found no clear signs of such events during the observation period.

Contribution

It provides the first coordinated spectroscopic and photometric search for CMEs in young stellar clusters, establishing observational constraints.

Findings

No clear CME signatures detected during observations.

Flares and CMEs may be less frequent or less detectable in these clusters.

Sets upper limits on CME occurrence in young stellar populations.

Abstract

On the Sun, the energetic, erupting phenomena of flares and coronal mass ejections (CMEs) often occur together. While space-based photometry has revealed frequent white-light flares for vast numbers of stars, only a handful of coronal mass ejections have been detected. Space-based photometry reveals the timing and detailed structure of flares. To detect CME signatures, however, optical spectroscopy is essential, as the ejected plasma can be detected by Doppler-shifted emission bumps in the Balmer-regions. We present a dedicated ground-based multi-object spectroscopic observations of the young, nearby Praesepe (600 Myr) and Pleiades (135 Myr) clusters to detect CMEs and flares parallel with the observations of Praesepe by the TESS satellite. During the 10 days of overlapping observations, we did not find any obvious signs of CMEs or flares in the H$\alpha$ region.