2008

Astrowatch

After the completion of S5, the two LIGO detectors with 4 km arms, H1 and L1, were taken offline to receive a number of incremental upgrades that, based on knowledge of the noise sources limiting initial LIGO, will improve their sensitivity by roughly a factor of 2. This program is referred to as Enhanced LIGO. The third detector, H2, was left online, in tandem with GEO600 to observe until the upgrades are complete, in a program called "Astrowatch".