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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"

18 results found.

  1. LIGO/Virgo S200112r: AstroSat CZTI upper limits
  2. LIGO/Virgo S200112r: Upper limits from Konus-Wind observations
  3. LIGO/Virgo S200112r : No significant candidates in TAROT - FRAM - GRANDMA observations.
  4. LIGO/Virgo S200112r: Upper limits from CALET observations
  5. LIGO/Virgo S200112r: Upper limits from Insight-HXMT/HE observations
  6. LIGO/Virgo 200112r: No counterpart candidates in Fermi-LAT observations
  7. LIGO/Virgo S200112r: not observable by Fermi-GBM
  8. LIGO/Virgo S200112r: not observable by Fermi-GBM
  9. LIGO/Virgo S200112r: upper limits from AGILE/GRID observations
  10. LIGO/Virgo S200112r: Swift/BAT in the South Atlantic Anomaly
  11. LIGO/Virgo S200112r: upper limits from AGILE/MCAL observations
  12. LIGO/Virgo S200112r: INTEGRAL was inactive at the time of the event
  13. LIGO/Virgo S200112r: Coverage and upper limits from MAXI/GSC observations
  14. LIGO/Virgo S200112r: No counterpart candidates in HAWC observations
  15. LIGO/Virgo S200112r : no neutrino counterpart candidate in ANTARES search
  16. LIGO/Virgo S200112r: Global MASTER-Net observations report
  17. LIGO/Virgo S200112r: Upper limits from IceCube neutrino searches
  18. LIGO/Virgo S200112r: Identification of a GW compact binary merger candidate

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Download all Circulars as a .tar.gz archive:
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