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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"

21 results found.

  1. Konus-Wind detection of GRB 250215A / EP250215a
  2. GRB 250215A / EP250215A: Encouraging Follow-up Observations of a BdHN I with a Rest-Frame Duration 2.3 s at z=4.61
  3. IceCube-Cascade 250215A: Upper limits from a search for additional neutrino events in IceCube
  4. GRANDMA/OPD observations of GRB250215A
  5. GRB 250215A / EP250215a: LCO detection of the afterglow
  6. GRB 250215A: Swift/UVOT Upper Limits
  7. GRB 250215A: COLIBRÍ/DDRAGO Optical Upper Limits on the Afterglow
  8. EP250215a / GRB 250215A : GTC redshift z = 4.61
  9. GRB 250215A: Fermi GBM Observation
  10. EP250215a / GRB 250215A : NOT optical observations
  11. GRB 250215A/EP250215a: 1.6m Mephisto optical observation report
  12. GRB 250215A / EP250215a: Gemini-South optical observation of a likely rebrightening
  13. GRB 250215A: Swift-XRT refined Analysis
  14. GRB 250215A: SVOM/GRM observation
  15. EP250215a / GRB 250215A: AstroSat CZTI detection
  16. GRB 250215A / EP250215a: SVOM/VT optical candidate comfirmation
  17. EP250215A/GRB 250215A: INTEGRAL SPI-ACS detection
  18. EP250215a / GRB 250215A (potentially): NOT likely optical counterpart
  19. EP250215a: EP-WXT detection and FXT follow-up observation of an X-ray transient
  20. Fermi GRB 250215A: Global MASTER-Net observations report
  21. GRB 250215A: Fermi GBM Final Real-time Localization

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