An Eye in the Sky

Refining and limiting the Hubble constant is one of the main goals of the Hubble Space Telescope (HST). The HST, launched in 1995, has been measuring the redshift and apparent magnitudes of cephiad variable stars in an effort to measure the Hubble constant with an error of plus or minus 10%. You will be using this data, downloaded from the internet, to calculate your own value for the Hubble constant and the age of the universe.