Photo/IllutrationAn artist’s rendition of a supernova at the moment of explosion, wherein a white dwarf star is surrounded by a blue layer of helium, whose pressure has triggered a nuclear fusion reaction in the central part of the star (Provided by a team of University of Tokyo researchers)

Researchers have reported successfully capturing the image of a supernova only half a day after an explosion of a white dwarf star, which is believed to occur only once in 100 years per galaxy.

Mamoru Doi, a professor of astronomy with the University of Tokyo, and his colleagues said that the white dwarf likely drew component helium from another star, whose weight triggered a nuclear fusion reaction. They said their finding will help elucidate the mechanisms of supernova explosions, which occur when stars of large masses come to the end of their lives.

The scientists on the team used a wide-field camera mounted on the National Astronomical Observatory of Japan’s Subaru Telescope in Hawaii, which can record high-precision images of multiple galaxies at a time. In April last year, they discovered a supernova within a short time of an explosion, at a distance of about 1.8 billion light years in the direction of the Virgo constellation, out of more than 100 supernovae they had been able to observe.

Analysis of light wavelengths and other considerations indicated that the characteristics of the observed light can be explained by the hypothesis that a large amount of helium surrounded a white dwarf and a nuclear fusion reaction occurred in the central part of the star.

One of the available hypotheses about the process of white dwarf explosions into supernovae has been confirmed for the first time by observation, the scientists said.

Their research results were published online on Oct. 4 in Nature, the British science journal.