An ESA observatory has captured a tiny star, measuring about eight percent of the Sun‘s mass, spewing a massive ‘super flare’ of X-rays. Throughout a few minutes only, the cosmic object emitted more than ten times the energy even the most powerful bursts spewed by the Sun contain.
The striking eruption raises an issue to astronomers, who did not think it is possible for such tiny cosmic bodies to eject such explosions of X-rays.
The star, known as J0331-27, is an L dwarf, which means that it is so tiny that it can barely be named a star. If it had any less mass, it would not be able to produce its own energy, the European Space Agency (ESA) said. Researchers observed the flare in data captured about 12 years ago by the European Photon Imaging Camera (EPIC), attached to ESA’s XMM-Newton X-ray observatory.
New and Unique Phenomenon
Flares are triggered when the magnetic field in a star’s atmosphere becomes volatile and crashes, emitting an explosive mass of stored energy that generates a dramatic brightening.
“This is the most interesting scientific part of the discovery because we did not expect L-dwarf stars to store enough energy in their magnetic fields to give rise to such outbursts,” according to Beate Stelzer, from the University of Tübingen’s Institute for Astronomy and Astrophysics in Germany and the National Institute for Astrophysics (INAF) in Italy.
Energy can be located in a star’s magnetic field by charged particles generated in high-temperature conditions, the ESA explained. The tiny J0331-27, though, has a low surface temperature for a star. The question that comes next is, how is a super flare even possible on such an object?
“We just don’t know—nobody knows,” Stelzer said.
Learning this new and unique event on the L dwarf has become the main focus for astronomers, who are now searching for more such instances.
“There is still much to be discovered in the XMM-Newton archive,” project leader Andrea De Luca of INAF said in a statement. “In a sense, I think it is only the tip of the iceberg.”
The study has been published this month in the journal Astronomy & Astrophysics.