This Hubble image shows RS Puppis, a type of variable star known as a Cepheid variable. As variable stars go, Cepheids have comparatively long periods — RS Puppis, for example, varies in brightness by almost a factor of five every 40 or so days
The picture shows Abell 2218, a rich galaxy cluster composed of thousands of individual galaxies. It sits about 2
This image shows NGC 121, a
Astronomers using the NASA/ESA Hubble Space Telescope have made images of several galaxies containing quasars, which act as gravitational lenses to amplify and distort images of the galaxies aligned behind them.