Luminous red nova

A luminous red nova (LRN) is an explosion in space. It is probably caused when two stars merge to become one. Their red colour is distinctive. The light curve near the star stays in the infared. Luminous red novae are different from normal novae. Those are explosions on the surface of white dwarf stars.

History and discovery
The first luminous red nova found was in the Messier 85 galaxy. It was discovered when people working at the Rickett Observatory were searching for supernovas. Astronomers from U.C. Berkeley and Caltech investigated it. They found that it was different from normal novae and thermal pulses. Afterwards, they announced that luminous red novae are a new type of star explosion.

More luminous red novae were found after the discovery. Researchers found V1309 Scorpii in 2008. The star system was a contact binary. Researchers were studying it for six years before it merged and exploded. In 2015, two different luminous red novae were found. One was in the Andromeda galaxy, and the other was in the Pinwheel galaxy. Astronomers think that in 2022, KIC 9832227 will merge and become a new luminous red nova. This star system is 1800 light years away from the Sun. A team from Calvin College found that the orbital period of the star system was slowing down and that the stars were coming closer to each other.

Traits
Luminous red novae have these traits:
 The luminosity of the explosion is between that of a supernova and that of a nova.
 The light of the explosion stays for a few weeks or a few months. It gradually becomes darker.
 These stars may not be as hot as normal stars.

References

Other websites
 Press release by Caltech "Caltech and Berkeley Astronomers Identify a New Class of Cosmic Explosions"

Category:Astronomical phenomena
Category:Variable stars