First Observing Run Ends

The first Observing Run (O1) of Advanced LIGO detectors ended today. The run started on September 18, 2015.

During these 4 months, the twin detectors at Hanford and Livingston have been collecting data at a sensitivity that's not yet at its peak but nevertheless is about 4 times higher than before the Advanced LIGO upgrade. LIGO plans to have a number of subsequent observing runs, while continuing to further improve the sensitivity of its instruments before each run. Upgrades will resume between now and the beginning of the second observing run (O2), scheduled to start later this year and to last about 6 months. The O2 will be followed by another round of upgrades and yet another observing run. A partner European project, Advanced Virgo, which is also undergoing an upgrade, is scheduled to join Advanced LIGO in a joint observing run later this year. Both instruments are planned to be observing at full sensitivity by 2021.

Photo l-r: LIGO observatories at Hanford, Washington and Livingston, Louisiana (Credit: Caltech/MIT/LIGO Lab)