First Demonstration of Early Warning Gravitational-wave Alerts

  • Ryan Magee (Creator)
  • Deep Chatterjee (Creator)
  • Leo P. Singer (Creator)
  • Surabhi Sachdev (Creator)
  • Manoj Kovalam Lakshmi Narasimha (Creator)
  • Geoffrey Mo (Creator)
  • Stuart Anderson (California Institute of Technology) (Creator)
  • Patrick R. Brady (Creator)
  • Patrick Brockill (Creator)
  • Kipp Cannon (Creator)
  • Tito Dal Canton (Creator)
  • Qi Chu (Creator)
  • Patrick Clearwater (Creator)
  • Alex Codoreanu (Creator)
  • Marco Drago (Creator)
  • Patrick Godwin (Creator)
  • Shaon Ghosh (Creator)
  • Giuseppe Greco (Creator)
  • Chad Hanna (Creator)
  • Shasvath J. Kapadia (Creator)



Gravitational-wave observations became commonplace in Advanced LIGO-Virgo's recently concluded third observing run. 56 nonretracted candidates were identified and publicly announced in near real time. Gravitational waves from binary neutron star mergers, however, remain of special interest since they can be precursors to high-energy astrophysical phenomena like γ-ray bursts and kilonovae. While late-time electromagnetic emissions provide important information about the astrophysical processes within, the prompt emission along with gravitational waves uniquely reveals the extreme matter and gravity during—and in the seconds following—merger. Rapid communication of source location and properties from the gravitational-wave data is crucial to facilitate multimessenger follow-up of such sources. This is especially enabled if the partner facilities are forewarned via an early warning (pre-merger) alert. Here we describe the commissioning and performance of such a low-latency infrastructure within LIGO-Virgo. We present results from an end-to-end mock data challenge that detects binary neutron star mergers and alerts partner facilities before merger. We set expectations for these alerts in future observing runs.
Date made availableApr 2021
PublisherSAO/NASA Astrophysics Data System (ADS)


  • Gravitational waves
  • Gravitational wave astronomy
  • Neutron stars
  • High energy astrophysics
  • Astrophysics - High Energy Astrophysical Phenomena
  • First demonstration of early warning gravitational-wave alerts

    Magee, R., Chatterjee, D., Singer, L. P., Sachdev, S., Kovalam, M., Mo, G., Anderson, S., Brady, P., Brockill, P., Cannon, K., Canton, T. D., Chu, Q., Clearwater, P., Codoreanu, A., Drago, M., Godwin, P., Ghosh, S., Greco, G., Hanna, C., Kapadia, S. J., & 16 othersKatsavounidis, E., Oloworaran, V., Pace, A. E., Panther, F., Patwary, A., De Pietri, R., Piotrzkowski, B., Prestegard, T., Rei, L., Sreekumar, A. K., Szczepanczyk, M. J., Valsan, V., Viets, A., Wade, M., Wen, L. & Zweizig, J., 6 Apr 2021, In: The Astrophysical Journal Letters. 910, 2, L21.

    Research output: Contribution to journalArticlepeer-review

    Open Access
    35 Citations (Web of Science)

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