Detailed cool star flare morphology with CHEOPS and TESS
Year: 2024
Type: article
Abstract: White-light stellar flares are proxies for some of the most energetic types of flares, and can inform us about the high-energy irradiation environment that exoplanets live in. We used 3-s cadence CHEOPS and 20-s cadence TESS light curves to study the morphology of white-light flares in a sample of 130 late K and M stars, particularly by resolving the components of multi-peak outbursts. To do this, we developed a software which is now becoming a part of the flare-finding search algorithm in the data analysis pipeline for the PLATO mission. Our findings suggest that high-impulse flares are more frequent than suspected from lower-cadence data, so that the highest flux values hitting close-in exoplanets might be more time-limited than expected. We found significant differences in the duration distributions of single and complex flare components, but not in their peak luminosity. A statistical analysis of the flare parameter distributions provides marginal support for their description with a log-normal instead of a power-law function, leaving the door open to several flare formation scenarios. We also present preliminary results for a parallel search for stellar granulation signals – still undetected in late K and M dwarfs - in the same stellar sample, using exquisite CHEOPS photometry. Theme(s): The Sun and Cool Stars in the Time Domain, Cool Stars as Stellar Systems
Author: Bruno, Giovanni
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W6949290199