Per flare of a supercold star known as SDSS J013333.08 + 003223.7.
Ultra-cold dwarfs (UCDs) are stellar or substellar objects of spectral class M with masses of no more than 0.3 solar masses. They have weak chromospheric emission and dim light in X-rays, but sometimes they show explosive activity at different wavelengths.
The discovery of new UCD flares and their detailed study is necessary to understand better these events’ origin and their interaction between ultracold stars’ magnetic fields and surfaces.
One tool that can help detect new outbreaks on UCDs in the GWAC. It is one of the main ground targets of the planned Space Variable Objects Monitor (SVOM) satellite, a joint Sino-French satellite mission dedicated to detecting and studying gamma-ray bursts (GRB).
Now a group of astronomers led by Li-Ping Xin of the National Astronomical Observatory of the Chinese Academy of Sciences (CAS) is reporting the discovery of a powerful flare on SDSS J013333.08 + 003223.7 – a UCD of spectral type M9. It was spotted 471 light-years away. The flash was found to be more powerful than the typical flashes usually recorded on UCD.
According to the study, the superflare’s bolometric energy ranged from 55.6 to 92.5 decillion erg, making it one of the most powerful flares on ultracold stars. Its magnetic strength was estimated at 3.6-4.7 kGs. The total duration of the flow from the beginning to the resting level was about 14,465 seconds.