We go to a number of planetarium conferences every year, and like most folks who work in the planetarium business selling things to other colleagues, we get hit up for “donations” to help support the costs of conferences. Frequently we’re given a choice of ways to donate money, and they’re given cute names like “Nova” sponsors or “supernova” sponsors. Recently we’ve been seeing the term “Hypernova” for a sponsor who gives some huge amount of money (like around $5,000 or $10,000). I guess these are perceived as hierarchies, much as silver, gold, and platinum are used commonly to describe credit cards with higher and higher amounts.

It’s not quite the same kind of hierarchy as stellar explosions though. While a nova might be perceived as the “weakest” of the mighty outbursts that flow from stars, and a supernova is a strong one, with a hypernova being a really strong one, these terms really refer to distinctly different types of stellar explosions.

According to the National Radio Astronomy Observatory online dictionary of astronomy terms, a nova is a star that abruptly increases in brightness by a factor of a million. A nova is caused in a binary star system where hydrogen-rich material is transferred to the surface of a white dwarf until sufficient material and temperatures exist to kindle explosive nuclear fusion.

Skip down to supernova, and you get this: an extremely violent explosion of a star many times more massive than our Sun. During this explosion, the star may become as bright as all the other stars in a galaxy combined, and in which a great deal of matter is thrown off into space at high velocity and high energy. The remnant of these massive stars collapse into either a neutron star or a black hole.

There isn’t a definition for hypernova yet, because astronomers are still trying to figure out the precise conditions that would lead us to call a super-supernova explosion a “hypernova.”

Which brings me to a very cool announcement this week from a consortium of researchers in Europe, the U.S. and Japan, linking hypernovas to gamma-ray bursts. Here’s the scoop, as told by the National Observatory of Japan’s Subaru Telescope:

An international research team, led by astronomers from the University of Tokyo, Hiroshima University, and the National Astronomical Observatory of Japan, used the Subaru telescope to obtain the spectrum of SN2003jd, a hypernova unaccompanied by a gamma-ray burst, and found the first evidence that it is a jet-like explosion viewed off-axis. Hypernovae are hyper-energetic Supernovae that are often associated with gamma-ray bursts. This result provides clear and firm evidence that all Hypernovae may be associated with gamma-ray bursts, but that gamma-ray bursts are observable only when jets produced by the hypernova explosion point towards Earth.

There’s more information at their web site, explaining the rationale behind the research.

All that being said, I find it amusing that a donor giving massive amounts of money is named after a stellar phenomenon that is so energetic, but yet is also can be so destructive and mysterious.