Hubble Astronomers Use Supernovae To Gauge Power Of Cosmic Lenses
Distant exploding stars observed by NASA’s Hubble Space Telescope are providing astronomers with a powerful tool to determine the strength of naturally-occurring “cosmic lenses” that are used to magnify objects in the remote universe.
Two teams of astronomers, working independently, observed three such exploding stars, called supernovae. Their light was amplified by the immense gravity of massive galaxy clusters in the foreground — a phenomenon called gravitational lensing. Astronomers use the gravitational lensing effect to search for distant objects that might otherwise be too faint to see, even with today’s largest telescopes.
“We have found supernovae that can be used like an eye chart for each lensing cluster,” explained Saurabh Jha of Rutgers University in Piscataway, N.J., a member of the Cluster Lensing and Supernova survey with Hubble (CLASH) team. “Because we can estimate the intrinsic brightness of the supernovae, we can measure the magnification of the lens.”