Observing Plans

Current Observing Plans

May, 2025 -- LIGO's fourth observing run has been extended a further six weeks, and is now expected to conclude on November 18, 2025. This six week extension of O4c is being implemented in order to increase the overlap with early science operations of the Rubin Observatory, which will begin in October 2025. With this extension, O4c itself will include 10 months of data.

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