An imagined superflare from a low-mass L dwarf star, an enormous explosion like one detected in 2017 that was 10 times more powerful than any in the Sun’s recorded history. Image: University of Warwick/Mark Garlick
A small, borderline star about the size of Jupiter some 250 light years from Earth has been caught in the act of emitting an enormous superflare, releasing the equivalent of 80 billion tons of TNT while triggering a 10,000-fold increase in brightness.
The flare was 10 times more powerful than any known outburst from the Sun, including the Carrington event in 1859 that disrupted telegraph services around the world and caused strong, widespread auroral displays.
“The activity of low mass stars decreases as you go to lower and lower masses, and we expect the chromosphere (where flares originate) to get cooler or weaker,” said James Jackman, a doctoral student at the University of Warwick and lead author of a paper about the eruption.
“The fact that we’ve observed this incredibly low mass star, where the chromosphere should be almost at its weakest, but we have a white-light flare occurring shows that strong magnetic activity can still persist down to this level.”
The star in question ...