November 15th, 2021

[9 November 2021 update; next update by 15 March 2022]

LIGO, Virgo, and KAGRA are closely coordinating to start the O4 Observing run together. We plan to start the O4 Observing run in mid-December 2022, despite local and global adversities.

LIGO projects a sensitivity goal of 160-190 Mpc for binary neutron stars. Virgo projects a target sensitivity of 80-115 Mpc. KAGRA should be running with greater than 1 Mpc sensitivity at the beginning of O4, and will work to improve the sensitivity toward the end of O4.

If you have any questions, please contact the Spokespersons:

  • Patrick Brady (Spokesperson, LIGO Scientific Collaboration)
        lsc-spokesperson_AT_ligo/org
  • Giovanni Losurdo (Spokesperson, Virgo Collaboration)
        virgo-spokesperson_AT_ego-gw/it
  • Jun’ichi Yokoyama (Board Chair, KAGRA Scientific Congress)
        kscboard-chair_AT_icrr/u-tokyo/ac/jp

(Please replace “_AT_” into “@” and replace “/” into “.” after it.)

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November 8th, 2021

LIGO-Virgo-KAGRA international gravitational-wave network released GWTC3 (Gravitational-Wave Transient Catalog 3) which covers all the convinced gravitational wave events until the end of Observing run 3 (March, 2020) and posted the articles. GWTC-3 added 35 events in the latter half period of O3, and now we have 90 convinced events after the first discovery of gravitational wave in 2015.

LIGO-Virgo-KAGRA will soon post the associated papers related to this catalog: test of general relativity, and also of the observational results of the joint run of KAGRA and GEO600 in April 2020.

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September 15th, 2021

[15 September 2021 update; next update by 15 November 2021]

The LIGO-Virgo-KAGRA Collaboration is continuing to evaluate and respond to the ongoing impacts of COVID-19 and adverse weather on preparations for the O4 observing run. As a result, we reiterate that O4 will not start before August 2022 and note that it may be further delayed. We will provide a more concrete plan in our next update, by 15 November 2021.

The readiness of both the LIGO-Hanford and the LIGO-Livingston detectors remains uncertain as delays due to COVID-19 and Hurricane Ida hitting Louisiana have affected the construction schedule for the Frequency Dependent Squeezing system. Hurricane Ida has also impacted the LIGO Livingston Observatory staff and their families. The full impacts are still being evaluated and mitigations are being identified.

Virgo has completed the integration of the upgrades for O4 and is now in a commissioning phase. The uncertainty in readiness of the Virgo detector is mainly driven by the progress of the instrument commissioning.

KAGRA is working to join O4 with Virgo and LIGO. A later start than August 2022 is preferable due to COVID-19 and staff limitations.

If you have any questions, please contact the Spokespersons:

● Patrick Brady (Spokesperson, LIGO Scientific Collaboration); lsc-spokesperson_AT_ligo/org
● Giovanni Losurdo (Spokesperson, Virgo Collaboration); virgo-spokesperson_AT_ego-gw/it
● Jun’ichi Yokoyama (Board Chair, KAGRA Scientific Congress); kscboard-chair_AT_icrr/u-tokyo/ac/jp
  (Please replace “_AT_” into “@” and replace “/” into “.” after it.)

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August 29th, 2021

KAGRA Scientific Congress announces the new board chair Jun’ichi Yokoyama (RESCEU, Univ. Tokyo).
He will lead KSC for the next two years after Hisaaki Shinkai (Osaka Inst. Tech.).

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July 15th, 2021

[15 July 2021 update; next update by 15 September 2021]

The LIGO-Virgo-KAGRA collaborations are making good progress in the updates of the Virgo (where installation of new hardware is complete), KAGRA, and LIGO detectors in preparation for O4. It is not yet possible to give a definitive start date for O4, as there are some continued supply chain delays and the impact of COVID continues. We can say at this time that the O4 observing run will not begin before August 2022. We expect to be able to give a better estimate for the start of O4 by 15 September 2021 and will issue an update then.

If you have any questions, please contact the Spokespersons:
● Patrick Brady (Spokesperson, LIGO Scientific Collaboration);
          lsc-spokesperson_AT_ligo/org
● Giovanni Losurdo (Spokesperson, Virgo Collaboration);
          virgo-spokesperson_AT_ego-gw/it
● Hisaaki Shinkai (Board Chair, KAGRA Scientific Congress);
          kscboard-chair_AT_icrr/u-tokyo/ac/jp
(Please replace “_AT_” into “@” and replace “/” into “.” after it.)

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June 29th, 2021

(from https://www.ligo.org/science/Publication-NSBHDiscovery/)

On January 5th 2020, the Advanced LIGO detector in Livingston, Louisiana in the US and the Advanced Virgo detector in Italy observed gravitational waves produced by the last few decaying orbits (inspiral), followed by the merger of the neutron star with the black hole. Just ten days later a second gravitational-wave signal from the inspiral and merger of a neutron star with a black hole, was observed, this time by both Advanced LIGO detectors (in Livingston and also in Hanford, Washington) and the Virgo detector. This is the first time gravitational waves have been observed from a mix of neutron stars and black holes. These new discoveries are nick-named GW200105 and GW200115.


The masses of neutron stars and black holes measured through
gravitational waves and electromagnetic observations.
(Image credit: LIGO-Virgo & Frank Elavsky, Aaron Geller, Northwestern University)
(See the science summary for details.)


Summary of our knowledge of the component masses of the objects
that produced GW200105 and GW200115.
(See the science summary for details.)

See the science summary  “A NEW SOURCE OF GRAVITATIONAL WAVES: NEUTRON STAR–BLACK HOLE BINARIES” for details.

Read a free preprint of the full scientific article here.

 

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April 21st, 2021

The 8th KAGRA international workshop (KIW) will be held on July 7-9 2021, hosted by the Korea Astronomy and Space Science Institute (KASI).


http://kiw8.org/

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