• Chunichi Shimbun


Two sisters from Mukaiyama Elementary School in Ichinomiya, Aichi Prefecture, have discovered a supernova, becoming rising stars in Japan’s astronomical society.

In December, 12-year-old Koto Tomita and her 9-year-old sister, Rino, spotted the stellar explosion together.

“We do not keep a record of the discoverer’s age, but (Rino is) probably the youngest in Japan,” said a representative of the National Astronomical Observatory of Japan, based in Mitaka, Tokyo.

Over 300 new supernovas are discovered annually around the world, with a few dozen reported from Japan.

In 2011, a 10-year-old Canadian girl made headlines for discovering a supernova, but to do so at the age of 9 is considered rare.

The supernova discovered by the girls is in the constellation of Cetus, which is about 900 million light-years away.

The sisters are volunteers in the Kiso Supernova Survey (KISS) project managed by Kiso Observatory from the Institute of Astronomy at the University of Tokyo.

They spotted the supernova from images taken on Dec. 19. It was later confirmed by two other KISS volunteers before it was reported to the International Astronomical Union headquartered in Paris.

On Jan. 23, the star was officially registered as “SN2014dy.”

This is the second find for Koto, who also contributed to a discovery made last August in the constellation of Pegasus.

“We cannot predict when a supernova will occur. It takes real interest and patience to find one,” said Hitoshi Yamaoka, an assistant professor from the Department of Physics at Kyushu University who has known the sisters for a few years.

“It’s a pleasure to watch their interest grow in the field. I hope the girls will become an inspiration to the next generation,” he added.

Koto received her first telescope on her seventh birthday because she “wanted to see the rabbits living on the moon,” and began observing the night sky.

When she was 9, she met the adviser for the Ichinomiya High School Earth science society and started joining the club’s activities five days a week.

She has been researching the brightness of the evening and night skies and sharing the data with the high school students.

In 2012, Koto became the youngest attendant to give a presentation in a meet organized by the Astronomical Society of Japan for high school students and joined the KISS project in 2013.

“I like observing the stars, but I’m better at analyzing,” she said.

Rino, her younger sister, became interested and joined her in February last year after watching her sister check through the vast volume of images at home in search of a supernova.

“It’s difficult. My eyes would get very tired. I want to be like my sister to quickly go through the images,” Rino said.

Commenting on their recent discovery, Rino said with a laugh: “I’m happy because it was the first time for me, but next time I want to find one by myself.”

This section, appearing Saturdays, features topics and issues from the Chubu region covered by the Chunichi Shimbun. The original article was published on March 4.

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