When giant stars die in impressive supernova blasts, about 99% of the energy released goes into producing a flood of neutrinos. These tiny, ghostly particles slip through tons of matter like it’s not even there. But a new generation of detectors will be able to catch them, telling us of the inner machinations of the deaths of stars.
In 1987 the astronomy world witnessed the closest supernova explosion seen in centuries, a blast set off from within the Large Magellanic Cloud, a mere 168,000 lightyears away. One of biggest surprises and delights of that explosion was the clear detection of neutrinos from the event.
Neutrinos are subatomic particles that barely even acknowledge the rest of the particles in the universe. They are produced in all kinds of nuclear reactions (everywhere from nuclear power plants to giant stars exploding), and trillions of them are flying through your body right now. But since they hardly ever interact with normal matter, you don’t even notice them.
The detection of neutrinos in 1987 was a big deal because it taught us that supernovae can create a tremendous amount of neutrinos. Indeed, less than 1% of the total energy of a supernova explosion goes into light. And given the fact that a single supernova can outshine entire galaxies, it’s amazing to contemplate the sheer number of neutrinos produced with the other 99% of the available energy.
Unfortunately, a combination of extreme distance and the ninja-like stealthiness of neutrinos means that our Earthbound detectors caught only a handful of neutrinos from the 1987 event.
But this time it will be different.
A collaboration of scientists from around the world is currently constructing DUNE, the Deep Underground Neutrino Experiment. This experiment will mainly detect neutrinos produced at Fermilab using a giant tank of liquid argon at the Sanford Underground Research Facility in South Dakota. But the facility is also capable of detecting neutrinos from cosmic sources, and Betelgeuse is a prime candidate.
Betelgeuse is a red giant star in the constellation Orion, about 548 lightyears away from us. This star is near the end of its life, and is due to go supernova any day now. Of course, in astronomy terms “any day now” means “within the next 100,000 years or so”.
But it could also mean…literally any day now. If Betelgeuse goes supernova, it will be visible during the daytime and produce enough light to cast shadows at night. And it will also generate an enormous flood of neutrinos, giving astronomers at DUNE an unprecedented front-seat view to the heart of a giant star in the last moments of its life.