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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"

20 results found.

  1. GRB 250925A: MAO/AZT-22 optical observations
  2. GRB 250925A: Mondy I-band optical observations
  3. GRB 250925A: Swift-XRT refined Analysis
  4. GRB 250925A: Swift/UVOT Upper Limits
  5. GRB 250925A: Swift-BAT refined analysis
  6. GRB 250925A: Mondy and AbAO optical observations
  7. GRB 250925A: COLIBRÍ photometric redshift
  8. GRB 250925A: SVOM/GWAC-F60A upper limit
  9. GRB 250925A/EP250925a: EP-WXT detection
  10. GRB 250925A : MITSuME Akeno optical upper limits
  11. GRB 250925A: JinShan optical observations
  12. GRB 250925A: 1.5m OSN optical detection and redshift with the 10.4m GTC/OSIRIS+
  13. GRB 250925A: COLIBRÍ optical photometry of the afterglow
  14. GRB 250925A: Optical Observations via Virtual Telescope Project, Italy
  15. GRB 250925A: NOT optical afterglow candidate
  16. GRB 250925A: Leavitt Observatory optical upper limit
  17. GRB 250925A: Enhanced Swift-XRT position
  18. GRB 250925A: GROWTH-India Telescope Upper Limits
  19. GRB 250925A: Swift detection of a burst
  20. Swift GRB 250925A: Global MASTER-Net observations report

Advanced

Download all Circulars as a .tar.gz archive:
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