An amateur astronomer in the city of Toyama has found his 13th supernova.

Masakatsu Aoki, 59, who runs a kimono store by day, takes to his telescope by night to hunt for supernovas. A supernova is the collapse of a supermassive star, an event that results in the biggest known explosion. Its precise mechanism is unclear.

Aoki made his latest discovery in his personal observatory in January. He reported it to the International Astronomical Union, an internationally recognized authority for assigning designations to celestial bodies. The supernova's existence has since been confirmed by other observatories and has been named SN2016C.

"I would be happy if this contributes to resolving the mysteries of supernova explosions," Aoki said.

Finding supernovas involves painstaking work as observers must choose from a vast number of galaxies what to shoot and must compare images taken at different times. Aoki spends hours examining hundreds of images every night.

Aoki says he first got interested in space in his 20s. At first he only focused on taking pictures, but he gradually felt he wanted to contribute to the study of the universe itself.

With advances in technology, equipment became affordable for amateur astronomers, Aoki says. He started observing space on his own in 1995 and spotted his first supernova the following year.

Toyama, as with the rest of the Hokuriku region, is not the best place to see stars, as the weather tends to be cloudy. Aoki has opened an observatory in Takayama, Gifu Prefecture, which he monitors remotely.