| 23rd of April 2021 |
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| A flare from Proxima Centauri |
| by MacGregor et al. |
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MacGregor et al. have reported
the discovery of an extreme flaring event from
the star Proxima Centauri
by the Australian Square Kilometre Array Pathfinder (ASKAP), Atacama
Large Millimeter/submillimeter Array (ALMA), Hubble Space Telescope
(HST), Transiting Exoplanet Survey Satellite (TESS), and the du Pont
Telescope. In the millimeter and far-ultraviolet bands, this
flare is the brightest ever detected, brightening by a factor of >1000
and >14,000 as seen by ALMA and HST, respectively.
The ASKAP observations show faint, ∼ 50% circularly-polarized emission throughout the entire 14-hour observation, including a slowly-declining flux component that is not seen on any other day of the campaign. But no radio burst counterpart was detected by ASKAP. This apparent lack of correlation between low-frequency (< 1 GHz) and higher frequency activity is commonly observed from active M-dwarf stars, and may indicate that the physical driver for low-frequency activity is independent of the processes driving flaring activity observed in higher-frequency wavebands The results of the study were reported this week in The Astrophysical Journal Letters. (Image credit: S. Dagnello, NRAO/AUI/NSF) |