Subaru Telescope Detects Most Distant and Ancient Supernovae in the Young Universe

A team of Japanese, Israeli, and U.S. astronomers used the Subaru Telescope to assemble the largest sample ever found of the most distant exploding stars called supernovae, which emitted their light about ten billion years ago, long before the Earth was formed.

The researchers used this sample of ancient supernovae to determine how frequently such explosions of stars occurred in the young universe.

Supernovae have substantial importance in astrophysics. They are nature's element factories: essentially all of the elements in the periodic table that are heavier than oxygen were formed through nuclear reactions immediately preceding and during these colossal explosions.

The explosions fling these elements into interstellar space, where they serve as raw materials for new generations of stars and planets.

Thus, the atoms in our bodies, like the calcium atoms in our bones or the iron atoms in our blood, were created in supernovae.

By tracking the frequency and types of supernova explosions back through cosmic time, astronomers can reconstruct the universe's history of element creation, from the plain mix of hydrogen and helium that existed for the first billion years or so after the Big Bang, up to the elemental richness we see today.

However, looking back in time requires looking out to great distances, which means that even these bright explosions are exceedingly faint and difficult to spot.

To overcome this obstacle, the team took advantage of a combination of the Subaru Telescope's assets: the huge light-collecting power of its large 8.2 meter primary mirror; the sharpness of its images, and the wide field of view of its prime focus camera (Suprime-Cam).

On four separate occasions, they pointed the telescope toward one single field called the Subaru Deep Field, which spans an area of the sky similar to that covered by the full moon and had previously been studied in great detail by Subaru scientists.

By "staring" with the telescope at this single field, they let the faint light from the most distant galaxies and supernovae accumulate over several nights at a time, thus forming a very long and deep exposure of the field.

Read more at the Subaru Telescope portal