In response to COVID-19, LIGO has decided to suspend its third observing run (O3) ahead of schedule. Originally planned to end on April 30, the observing run will end on March 27th. LIGO made this decision to do its part to protect staff and each site's community from the virus. Despite its early retirement, O3 has been enormously successful! LIGO Image Credit: LIGO-Virgo Collaboration. Sunset Credit: Getty Images.

LIGO Suspends Third Observing Run (O3)

News Release • March 26, 2020

LIGO and Virgo will suspend the O3 run on 27 Mar 2020 at 17:00 UTC. It is unknown at this time whether observing mode operation may resume in the near furture, as the current worldwide COVID-19 pandemic demands that we make public health and safety our top priority.

O1 to O3 cumulative detection graphic

LIGO's third observing run yielded 56 gravitational-wave detections. That's 5-times more than were collectively made during the first two observing runs of the Advanced detector era (O1 and O2 yielded 11 gravitational wave detections). Image credit: LIGO-Virgo Collaboration.


The LIGO Laboratory, LIGO Scientific Collaboration, EGO, and Virgo Collaboration leadership are working to ensure that the transition out of O3 is smooth and preserves the potential science to be conducted with LIGO-Virgo data. In particular, this means rapidly carrying out critical detector measurements and calibrations needed to ensure O3b data integrity and quality. The remaining days of the run will have some time set aside for these measurements and to complete the transition.

Design and contracting activities associated with LIGO detector upgrades will continue. At this point, it is impossible to say how COVID-19 might affect the planned LIGO A+ upgrade, beyond noting that there are indeed likely impacts. LIGO Scientific Collaboration and Virgo data processing, scientific analysis, and work on papers continues, being well-suited to the constraints imposed by COVID-19.

In spite of the early suspension, the O3 run has been a tremendous success. We are grateful to everyone in the LIGO Lab, the LSC, and Virgo for their work during this very successful observing run, and we look forward to both bringing the results to publications as quickly as feasible, and getting back to work on the A+ upgrade. 

We wish all safe-passage through this difficult time.