In the galaxy M82 (pictured), a mere 12 million light years from Earth, an enormous but invisible supernova has disturbed its local volume with massive shockwaves. The supernova, the closest to Earth in the past five years, can only be detected via radio waves.
In other words, it is emitting only radio waves, and at last astronomers have access to a powerful radio wave detector - the Allen Telescope Array (pictured below) - which allows them to see these previously difficult-to-find astronomical objects.
UC Berkeley astronomer Geoffry Bower, whose paper on the discovery will appear next month in Astronomy and Astrophysics, said:
This supernova is the nearest supernova in five years, yet is completely obscured in optical, ultraviolet and X-rays due to the dense medium of the galaxy.This just popped out; in the future, we want to go from discovery of radio supernovas by accident to specifically looking for them . . . The ATA can detect objects at least 10 times fainter than this radio supernova, which pushes our survey an order of magnitude deeper than other radio surveys with more attention to transient and variable sources. Radio supernovas are a really strong aspect of that survey. This [new radio supernova] is the kind of discovery that we would like to make with the Allen Telescope Array.
The supernova erupted last year in the heart of the M82 galaxy, and has sent out a ring-shaped shockwave that is disturbing the interstellar medium - that ring is about 2,000 astronomical units across. The research team ruled out the possibility that this explosion might be something other than a supernova after examining the ring, and looking back at previous surveys of the galaxy, which revealed that the region had been much brighter last year, and slowly faded in a pattern indicative of a massive explosion.
Using the ATA, scientists hope to detect more of these mysterious, invisible supernovas throughout the universe.
Rare Radio Supernova via Eurekalert!
M82 Image Credit: M. Mountain (STScI), P. Puxley (NSF), J. Gallagher (U. Wisconsin)