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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

17 results found.

  1. LIGO/Virgo S191215w: Upper limits from Konus-Wind observations
  2. LIGO/Virgo S191215w: Updated Sky Localization
  3. LIGO/Virgo S191215w : No significant candidates in TAROT - FRAM - GRANDMA observations.
  4. LIGO/Virgo S191215w: No transient candidates in CALET observations
  5. LIGO/Virgo S191215w: no counterpart candidates in the Swift/BAT observations
  6. LIGO/Virgo S191215w: No counterpart candidates in Fermi-LAT observations
  7. LIGO/Virgo S191215w: AstroSat CZTI upper limits
  8. LIGO/Virgo S191215w: upper limits from AGILE-GRID observations
  9. LIGO/Virgo S191215w: upper limits from AGILE/MCAL observations
  10. LIGO/Virgo S191215w: Upper limits from Fermi-GBM Observations
  11. LIGO/Virgo S191215w: No counterpart candidates in HAWC observations
  12. LIGO/Virgo S191215w: Coverage and upper limits from MAXI/GSC observations
  13. LIGO/Virgo S191215w : no neutrino counterpart candidate in ANTARES search
  14. LIGO/Virgo S191215w: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  15. LIGO/Virgo S191215w: Identification of a GW compact binary merger candidate
  16. LIGO/Virgo S191215w: Global MASTER-Net observations report
  17. LIGO/Virgo S191215w: Upper limits from IceCube neutrino searches

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Download all Circulars as a .tar.gz archive:
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