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 supernovas 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.

Link

More info: Subaru telescope web page