Searching for stellar flares from low-mass stars using ASKAP and TESS

Abstract

Solar radio emission at low frequencies (<1 GHz) can provide valuable information on processes driving flares and coronal mass ejections (CMEs). Radio emission has been detected from active M dwarf stars, suggestive of much higher levels of activity than previously thought. Observations of active M dwarfs at low frequencies can provide information on the emission mechanism for high energy flares and possible stellar CMEs. Here, we conducted two observations with the Australian Square Kilometre Pathfinder Telescope (ASKAP) totalling 26 hours and scheduled to overlap with the Transiting Exoplanet Survey Satellite (TESS) Sector 36 field, utilising the wide fields of view of both telescopes to search for multiple M dwarfs. We detected variable radio emission in Stokes I centered at 888 MHz from four known active M dwarfs. Two of these sources were also detected with Stokes V circular polarisation. When examining the detected radio emission characteristics, we were not able distinguish between the models for either electron cyclotron maser or gyrosynchrotron emission. These detections add to the growing number of M dwarfs observed with variable low frequency emission.

Photometric Observations of Flares on AD Leo from GWAC-F30 and TESS

“…Cumulative flare frequency distribution (FFD) presents the relationship of energies and burst rates of flares (Gershberg 1972;Lacy et al 1976;Hunt-Walker et al 2012;Paudel et al 2018). To determine the bolometric flare energies, we assume the flare temperature is about 12,000 K (Rigney et al 2022). The fraction of the flux that falls within the B band is calculated as about 0.15, and for the TESS band is about 0.14 which is the same that was applied in previous research (Schmitt et al 2019;Rigney et al 2022) 2).…”

“…To determine the bolometric flare energies, we assume the flare temperature is about 12,000 K (Rigney et al 2022). The fraction of the flux that falls within the B band is calculated as about 0.15, and for the TESS band is about 0.14 which is the same that was applied in previous research (Schmitt et al 2019;Rigney et al 2022) 2).…”

Evolutionary Map of the Universe (EMU): A pilot search for diffuse, non-thermal radio emission in galaxy clusters with the Australian SKA Pathfinder

“…Figure 2 shows the distribution of clusters and selected observations across the sky, and Table 2 summarises the 71 clusters. The selected SBIDs include observations from the EMU Pilot Survey (Norris et al, 2021), Gravitational wave follow-up observations, SWAG-X, TESS follow-up observations (Rigney et al, 2022), a POSSUM observation that is commensal with EMU, and various other EMU early science and commissioning observations (e.g. Brüggen et al, 2021;Gürkan et al, 2022;Quici et al, 2021).…”