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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"

14247 results found.

  1. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  2. GRB 990123: Continued Radio Observations
  3. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  4. GRB 990123 Optical Follow-Up
  5. GRB 990123; Addendum to GCN 223
  6. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  7. GRB 990123 Optical Follow-Up
  8. GRB 990123: Possible Gravitationally Lensed Burst?
  9. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  10. GRB 990123 radio observations
  11. GRB990123, early optical counterpart detection
  12. GRB990123, BeppoSAX-NFI X-ray afterglow detection
  13. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  14. GRB981220
  15. GRB 981220 Optical observations
  16. GRB 981226 Optical Observations
  17. GRB 981226
  18. GRB 981226 optical observations
  19. GRB981220 B, R and I band observations
  20. Optical Observations of GRB981226
  21. GRB 981220
  22. GRB 980326/Host Galaxy
  23. GRB 980923 BATSE Observations
  24. Optical Observations of the Host Galaxy of GRB 980519
  25. GRB980703 - BeppoSAX/GRBM detection
  26. RXTE Observation of GRB 980706
  27. GRB980703: LOTIS observation at early times
  28. GRB980613 Optical Observations
  29. GRB 980703 H-band Observations
  30. GRB980703 optical followup
  31. GRB 980613: Detection of the probable host galaxy
  32. GRB 980613 optical observations
  33. GRB 980519 Optical Observations
  34. GRB980519 optical observations
  35. GRB980519 optical observations
  36. GRB980519 optical observations
  37. BSAX Observations of GRB980425 field
  38. GRB 980329 ROSAT observation
  39. GRB980326, optical observations
  40. GRB980329
  41. GRB980329 Keck K-band observations
  42. GRB980329 optical observations
  43. Optical Observations of the GRB 971227 field
  44. GRB971227: Further CAHA R-band images
  45. GRB 971227: CAHA R-band images
  46. GRB 971214: Redshift from Keck Optical Observations
  47. GRB 971214: KPNO Optical Observations

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Download all Circulars as a .tar.gz archive:
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