Physics + Math

01
Nov

Can We Spot a Milky Way Supernova from Earth?

A supernova in our home galaxy might be visible from Earth within the next 50 years.

While scientists are able to observe supernovae outside our galaxy every few days, they’ve never been able to detect one fast enough to get meaningful data on it. Given the right equipment, though, the heat signature from a Milky Way supernova could be visible from Earth as long as we locate it quickly enough—and, it could tell astronomers what happens at the very beginning of a star’s death.

supernova-1987
Supernova 1987A was the closest exploding star seen in modern times.

Cosmic soot can obscure optical light from stars by a factor of nearly a trillion by the time it reaches Earth. Infrared light, though, is less affected by dust and fades by a factor of 20, so a team led by Scott Adams of Ohio State University explains in a new study that scientists would have to use a specialized infrared telescope to see the supernova. Here’s Elizabeth Howell writing for Universe Today:

To jump on the supernova as it is happening, the scientists propose having a network in place to send out neutrino alerts when these particles, which would arrive at Earth first after an explosion, are detected on Earth. The key is to figure out the difference between neutrinos from space and neutrinos from other sources, such as nuclear reactors, the sun or even spurious glitches.

“When a neutrino from a Milky Way supernova enters the tank, it can collide with the water molecules and release energy, along with some neutrons,” Ohio State added. ”Gadolinium has a great affinity for neutrons, and will absorb them and then re-emit energy of its own. The result would be one detection signal followed by another a tiny fraction of a second later—a “heartbeat” signal inside the tank for each detected neutrino.”

This network, coupled with the potency of an infrared telescope, could allow scientists to see a Milky Way supernova. The chances of spotting one with the naked eye, though, are lower and depend on the viewer’s latitude. Here’s Brett Smith writing for RedOrbit:

Adams determined between a 20 and 50 percent chance of seeing a galactic supernova with the unaided eye from somewhere on Earth within the next 50 years. Observers in the southern hemisphere would get the best chance because they can see more of the Milky Way in their night sky. As latitude of the observer increases, the chance of seeing a supernova drops, to as low as 10 percent in Ohio, for example.

In 1604, when Johannes Kepler famously spotted a supernova about 20,000 light years away, he was in northern Italy at the time. Adams said the odds Ohioans would see a similar dazzling supernova is only around 5 percent.

Very large supernovae sometimes turn into black holes. Does a black hole lurk in the center of our galaxy? Watch “Monster of the Milky Way” to find out:

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