LIGO, Virgo and KAGRA Begin the IR1 Observing Run
NSF LIGO - Hanford, 127124, North Route 10, Richland, Benton County, Washington, 99354, United States
LIGO
ESTIMATED68% CONFIDENCEThe collaborations' own observing plan, last updated 3 September 2026, gives only a window - a six-month run "beginning early- to mid-November of 2026" - and says the next update is due 15 October 2026 or sooner. With no day named, the pin takes the close of the stated window rather than its start, so it is not early; it moves when the collaborations name the day.[1]
The gravitational-wave detectors start a six-month intermediate observing run before the fifth observing run. Both LIGO detectors take part, Virgo joins despite possible maintenance interruptions, and KAGRA joins as it becomes available.
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