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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"

28063 results found.

  1. GRB 990123 radio observations
  2. GRB 990123, new radio source
  3. GRB 990123: Optical Decay Slope
  4. GRB 990123 r-band photometry
  5. GRB990123, early optical counterpart detection
  6. GRB990123, BeppoSAX-NFI X-ray afterglow detection
  7. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  8. Optical Observations of GRB 981220
  9. GRB981220
  10. GRB 981220 Optical observations
  11. GRB 981226 Optical Observations
  12. GRB981226 Optical Observations
  13. GRB 981226
  14. GRB 981226 optical observations
  15. GRB981220 B, R and I band observations
  16. Optical Observations of GRB981226
  17. GRB 981220
  18. GRB 981220, radio observations
  19. GRB 980326/Host Galaxy
  20. GRB980425 Optical Follow-up
  21. GRB980703 Very Long Baseline Interferometry
  22. Optical Observations of the Host Galaxy of GRB 980519
  23. GRB980703 - BeppoSAX/GRBM detection
  24. GRB980703: Radio transient
  25. GRB 980703: Spectrum of the proposed optical counterpart
  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 980613 optical observations
  34. GRB980613 Optical Observations
  35. GRB980613 BeppoSAX-NFI follow up
  36. GRB 980519 Optical Observations
  37. GRB 980519
  38. GRB980519 optical observations
  39. GRB980519 optical observations
  40. GRB980519 optical observations
  41. GRB980515, BeppoSAX IAUC to be submitted
  42. BSAX Observations of GRB980425 field
  43. SAX J0840.7+2248 Optical Observations
  44. GRB 980329 ROSAT observation
  45. GRB980326 X-ray Observations
  46. GRB980326, optical observations
  47. GRB980329, Fading IR counterpart to radio source
  48. GRB980329
  49. GRB980329 Keck K-band observations
  50. GRB980329 sub-millimeter observations
  51. GRB980329 near-IR observations
  52. GRB980329 optical observations
  53. GRB980329 optical observations
  54. GRB980329 VLA observations
  55. GRB980329 optical observations
  56. Near-IR follow-up on GRB 971227
  57. Optical Observations of the GRB 971227 field
  58. GRB971227: Plaskett R-band observations
  59. GRB 971227: Optical clarifications
  60. GRB971227: Further CAHA R-band images
  61. GRB 971227: CAHA R-band images
  62. GRB 971214: Redshift from Keck Optical Observations
  63. GRB 971214: KPNO Optical Observations

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