Observing Plans

Current Observing Plans

June, 2024 -- The second half of O4 (O4b) began on April 10th, 2024 after a nearly 3-month period within which a number of upgrades and maintenance tasks were performed on the Livingston and Hanford detectors. O4 is now expected to extend into June 2025.

Current (as of June 2024) timeline for the O4 observing run

For more information on LIGO/Virgo/KAGRA observing plans for O4, please see IGWN Observing Plans, and for a longer term outlook, please visit

LIGO/Virgo/KAGRA Statement on Near-term Observing Plans

Future Observing Plans

Plans are currently under development by LIGO to chart a path for interferometer upgrades and observing periods beyond O5 and continuing into the next decade.

LIGO Laboratory Statement on Long-term Future Observing Plans