Building the Universe: Most Ancient Supernovas Discovered

Supernovas are the astrophysical equivalent of early Black Flag records. They are short, violent bursts whose aftereffects endure long after the initial explosion has quieted. A group of astronomers at Tel Aviv University has thus found the equivalent of a box of long-lost seven-inches: a section of the universe with a record-breaking density of supernovas, including some of the oldest ever discovered.

In real terms, a supernova is a massive explosion that serves as the final gasp of a dying star. In astronomical terms, their short life makes them hard to capture. The only way to see a really old supernova is to find one really far away. Of course, finding objects of interest gets increasingly difficult with distance as the limits of telescopes are reached. Plus, there’s the simple fact that, the farther away you look, the more there is too look at.

The research team, led by Professor Dan Maoz, Dr. Dovi Poznanski and Or Graur of TAU’s Department of Astrophysics, headed a project looking at the Subaru Deep Field, a patch of sky that contains about 150,000 galaxies. The end result was a total of 150 observed supernovas, including 12 that are some of the most distant and most ancient ever discovered. The team said getting such a vast grouping of new supernovas to ogle helps advance our knowledge of how they work.

That they’re kick-ass thermonuclear fireworks aside, why the big fuss over supernovas? Well, we can thank them for pretty much everything that exists. Supernovas are basically the element factories of the universe.

The early universe, and stars themselves, was and are mostly composed of the lightest elements, with helium and hydrogen making up the vast majority of everything in existence. The incredible element-fusing power of supernovas created a vast portion of the universe’s building blocks. Those heavier elements have since swirled together to create all celestial bodies, including Earth.

According to the team’s research, thermonuclear supernovas were about five times more frequent 10 billion years ago than they are today. These Type-Ia supernovas are responsible for creating and propelling much of the iron scattered about the universe. The TAU team’s work, conducted using the Japanese Subaru Telescope on Mauna Kea in Hawaii, has helped expand the small base of knowledge of how supernovas actually work. This provides valuable background for research into the role of dark matter in our expanding universe, like the work that won this year’s Nobel Prize in physics.