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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"

18283 results found.

  1. GRB 990123 Optical Follow-Up
  2. GRB 990123: Possible Gravitationally Lensed Burst?
  3. GRB990123, optical observation
  4. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  5. GRB 990123 r-band photometry
  6. GRB 990123 Optical Follow-up
  7. Optical Observations of GRB 981220
  8. GRB 981226: radio variable
  9. GRB 981226 Optical Observations
  10. GRB981226 BeppoSAX follow up
  11. GRB 981226
  12. GRB 981226 optical observations
  13. GRB 981220:Optical Observations
  14. GRB981226, BeppoSAX Christmas GRB
  15. GRB 981226 optical observations
  16. GRB 981220, radio observations
  17. GRB 981220
  18. GRB 980326/Host Galaxy
  19. BeppoSAX NFI Observation of GRB980425
  20. GRB980329 R,I flux calibration and R,I,K upper limits
  21. GRB980425 Optical Follow-up
  22. GRB970508 optical observations
  23. GRB980519, Optical Observations
  24. GRB 980703 (NFI observations)
  25. GRB980703 optical photometry
  26. GRB980703 optical observations
  27. GRB980703: Radio transient
  28. GRB980703 Transient Optical Follow-Up
  29. GRB980703: LOTIS observation at early times
  30. BeppoSAX NFI observations of GRB 980703
  31. GRB980703 optical followup
  32. SGR1627-41
  33. Radio observations of SGRs
  34. SGR1900+14 field optical observations
  35. GRB 980613 Near-IR observations
  36. GRB 980613: Optical transient and its host galaxy
  37. SGR1627-41, Refined IPN annulus location
  38. GRB 980613: Detection of the probable host galaxy
  39. SGR 1627-41
  40. GRB 980613 Optical Observations
  41. GRB 980613 optical observations
  42. Discovery of a new SGR source, SGR1627-41
  43. GRB980613 Optical Observations
  44. GRB980613 observations from Palomar
  45. GRB980613 Near Infra-Red Observations
  46. GRB971214 Secondary Standards
  47. GRB980519 Secondary Standards
  48. GRB 980519 Optical Observations
  49. GRB 980519
  50. GRB980519 optical observations
  51. GRB 980519 Optical Observations
  52. GRB980519 Optical Observations
  53. GRB 980519 Optical Observations
  54. GRB980515, BeppoSAX IAUC to be submitted
  55. BSAX Observations of GRB980425 field
  56. SAX J0840.7+2248 Optical Observations
  57. GRB980425: optical obs.
  58. GRB980425: Radio Observations
  59. report on BSAX observations of GRB980425
  60. GRB980326 X-ray Observations
  61. GRB980326, optical observations
  62. GRB980326, optical observations
  63. GRB980326 IPN annulus
  64. GRB980329 Keck K-band observations
  65. GRB980326 optical observations
  66. GRB980329 optical observations
  67. GRB980329 VLA observations
  68. GRB980329 optical observations
  69. GRB980326 optical observations
  70. Optical Observations of GRB 970508
  71. Near-IR follow-up on GRB 971227
  72. Optical Observations of the GRB 971227 field
  73. Optical Observations on GRB 971227
  74. GRB971227: Plaskett R-band observations
  75. GRB 971227: Optical clarifications
  76. GRB971227: Further CAHA R-band images
  77. GRB971227: LOTIS observations
  78. GRB 971227: CAHA R-band images
  79. GRB971214: Optical Observations and Calibrations
  80. GRB 971214: Optical Observations
  81. Radio Observations of GRB 971214 at the VLA
  82. GRB 971024: KPNO Optical Observations
  83. GRB 970828: Palomar Observations

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