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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.

Lucene Examples (click to copy):

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

21 results found.

  1. IceCube Alert 220220.60:NuEm-220220A: MASTER optical possible counterpart
  2. GRB 201014A: 2.0m HCT upper limit
  3. GRB 201014A: SAO RAS optical observations
  4. GRB 201014A: 3.6m DOT Optical Observations
  5. GRB 201014A: MMT afterglow detection
  6. IceCube-201014A: No significant detection in HAWC
  7. GRB 201014A: Nanshan/NEXT optical observations
  8. GRB 201014A: Lowell Discovery Telescope afterglow imaging
  9. GRB 201014A: Redshift from GTC/OSIRIS
  10. GRB 201014A: Swift/UVOT Upper Limits
  11. GRB 201014A: Swift-XRT refined Analysis
  12. IceCube-201014A: Upper limits from a search for additional neutrino events in IceCube
  13. GRB 201014A: BOOTES-1 and -2 early optical upper limits
  14. GRB 201014A: Swift-BAT refined analysis
  15. GRB 201014A (Swift trigger =1000255): CrAO/ZTSH optical afterglow discovery
  16. Swift-BAT trigger 1000255: XRT afterglow detection of GRB 201014A
  17. IceCube-201014A: No neutrino counterpart candidates in ANTARES search
  18. Fermi-LAT Gamma-ray Observations of IceCube-201014A
  19. IceCube-201014A: Not observable by GBM
  20. IceCube-201014A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  21. IceCube-201014A - IceCube observation of a high-energy neutrino candidate track-like event

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Download all Circulars as a .tar.gz archive:
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