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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"
  1. GRB010222: Another absorption line system
  2. GRB010222: Optical decay slope
  3. GRB 010214, Optical Observations
  4. GRB010222: Sub-millimeter detection
  5. GRB010222: R-band fading behavior
  6. GRB010222: Optical Observations
  7. GRB010222, radio observations
  8. GRB010222, optical observations
  9. GRB010222: BeppoSAX/NFI Observations
  10. Redshift of the Optical Transient of GRB010222
  11. GRB010214B,Gamma Ray Observations
  12. GRB010222: possible optical counterpart
  13. GRB010222
  14. GRB010222
  15. GRB010222: BeppoSAX refined position
  16. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  17. GRB010220, Radio and Optical Observations
  18. GRB 010220, simultaneous optical observations
  19. GRB010220: BeppoSAX WFC and GRBM preliminary data
  20. GRB010214, candidate optical afterglow
  21. GRB010214, optical observations
  22. BeppoSAX GRB010220: refined position
  23. BeppoSAX ALERT: GRB010220
  24. GRB010214: BeppoSAX WFC and GRBM preliminary data
  25. GRB 010214: X-Ray afterglow
  26. GRB 010214, Optical Observations
  27. GRB 010214 optical observation
  28. GRB010213, Radio Observations
  29. GRB010213 Optical Observation
  30. GRB010213, Radio Observations
  31. J-Band Observation of GRB 010214.
  32. GRB010214, Radio Observations
  33. GRB010214, optical observations
  34. GRB010213, optical observations
  35. GRB010213, Near-IR observations
  36. Possible InfraRed Transient of GRB 010214.
  37. GRB010214 Optical Observation
  38. GRB010214: BeppoSAX/NFI Observations
  39. GRB010213 (HETE) TAROT observations
  40. GRB 010214, optical observations
  41. GRB010213 detected by HETE
  42. GRB010214 refined WFC position
  43. BeppoSAX ALERT: GRB010214
  44. IPN Status Report
  45. HETE Status
  46. GRB010126 opt. obs.
  47. IPN/RXTE TRIANGULATION OF GRB010126
  48. GRB010126: CONCAM crude optical limits during GRB
  49. GRB010126, TNG R-band observations
  50. GRB010126 Optical Observations
  51. GRB010126 optical observations
  52. GRB010126: Optical observations
  53. IPN TRIANGULATION OF GRB010126
  54. IPN/RXTE TRIANGULATION OF GRB010126
  55. GRB 010119, optical observations
  56. GRB010119: Optical observations
  57. Optical Observations of GRB 001018 at Keck
  58. GRB010119, Radio observations
  59. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  60. Optical observations of GRB 001018 with JCAM
  61. IPN TRIANGULATION OF GRB010115
  62. IPN TRIANGULATION OF GRB010109
  63. IPN TRIANGULATION OF GRB010109
  64. GRB010103, optical observations
  65. IPN triangulation of GRB010104
  66. IPN triangulation of GRB010103
  67. GRB 001204: Ks observations
  68. H band observation of GRB 001212
  69. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  70. IPN triangulation of GRB001219
  71. GRB 001212 Optical Observation
  72. GRB 001212 Optical Observation
  73. GRB 001212 optical observation
  74. GRB 001212 possible OA in 2MASS
  75. GRB 001212 possible OA
  76. IPN triangulation of GRB001212
  77. GRB001204: Optical observations
  78. Confirmation of IPN position for GRB001204
  79. GRB001204, Radio observations
  80. IPN triangulation of GRB001204 (short/hard)
  81. GRB 001105, further optical observations
  82. GRB001120: Gunn-i observations
  83. GRB001120: Optical observations
  84. GRB001109, optical observations
  85. GRB001120, optical observations
  86. WSRT 4.8 GHz observations of GRB001109
  87. IPN triangulation of GRB001120
  88. Optical/NIR observations of GRB001109
  89. GRB 001109: deep JHK upper limits
  90. GRB 001109 X-ray afterglow with BeppoSAX
  91. CORRECTION to XMM-Newton observation of GRB001025
  92. GRB001109: Optical observations
  93. GRB001109: BeppoSAX/NFI Observations
  94. GRB001109, R-band optical observations
  95. GRB001109, Radio observations
  96. GRB001109: BeppoSAX refined WFC position
  97. BeppoSAX ALERT: GRB001109
  98. GRB001105 BVRI field photometry correction
  99. GRB001105, BVRI field photometry
  100. GRB 001105, R-band observation

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