Experiment

MAXI detects a "fireball," succeeds in observing a nova explosion.

Monitor of All-sky X-ray Image (MAXI) onboard the International Space Station (ISS) had detected a nova, after named as MAXI J0158-744, in a direction of the Small Magellanic Cloud which emits extraordinary luminous soft X-ray (low energy X-ray) transient with 100 times larger than those of normal nova explosions.

Combining Swift satellite's observation data, the transient was confirmed that it was the huge luminosity emitted by a "fireball" dwarf, an early explosion phase of a massive white dwarf. Observing soft X-ray transient of a "fireball" is the world's first. MAXI enabled this detection because it monitors burst events in all-sky within the soft X-ray wavelength.

Meanwhile, MAXI's Solid-state Slit Camera (SSC) had detected ionized neon X-ray emission line in the transient.

The phenomenon affects the nova explosion theory as it is unable to explain by the existing theory. In addition, expected mass of white dwarfs exceed the existing theoretical prediction, it also may affect wide scope of astronomy.

The result was published on Astrophysical Journal, Volume 779, Number 2, 2013 December 20.

*All times are Japan Standard Time (JST)