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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').
  1. GRB 010222: Near-IR Observations
  2. GRB 010222: Optical Observations
  3. GRB 010222, Decay Slope Confirmed
  4. GRB010222: Another absorption line system
  5. GRB010222: Optical decay slope
  6. GRB 010214, Optical Observations
  7. GRB010222: Sub-millimeter detection
  8. GRB010222: R-band fading behavior
  9. GRB010222: Optical Observations
  10. GRB010222, radio observations
  11. GRB010222, optical observations
  12. GRB010222: BeppoSAX/NFI Observations
  13. Redshift of the Optical Transient of GRB010222
  14. GRB010214B,Gamma Ray Observations
  15. GRB010222: possible optical counterpart
  16. GRB010222
  17. GRB010222
  18. GRB010222: BeppoSAX refined position
  19. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  20. GRB010220, Radio and Optical Observations
  21. GRB 010220, simultaneous optical observations
  22. GRB010220: BeppoSAX WFC and GRBM preliminary data
  23. GRB010214, candidate optical afterglow
  24. GRB010214, optical observations
  25. BeppoSAX GRB010220: refined position
  26. BeppoSAX ALERT: GRB010220
  27. GRB010214: BeppoSAX WFC and GRBM preliminary data
  28. GRB 010214: X-Ray afterglow
  29. GRB 010214, Optical Observations
  30. GRB 010214 optical observation
  31. GRB010213, Radio Observations
  32. GRB010213 Optical Observation
  33. GRB010213, Radio Observations
  34. J-Band Observation of GRB 010214.
  35. GRB010214, Radio Observations
  36. GRB010214, optical observations
  37. GRB010213, optical observations
  38. GRB010213, Near-IR observations
  39. Possible InfraRed Transient of GRB 010214.
  40. GRB010214 Optical Observation
  41. GRB010214: BeppoSAX/NFI Observations
  42. GRB010213 (HETE) TAROT observations
  43. GRB 010214, optical observations
  44. GRB010213 detected by HETE
  45. GRB010214 refined WFC position
  46. BeppoSAX ALERT: GRB010214
  47. IPN Status Report
  48. HETE Status
  49. GRB010126 opt. obs.
  50. IPN/RXTE TRIANGULATION OF GRB010126
  51. GRB010126: CONCAM crude optical limits during GRB
  52. GRB010126, TNG R-band observations
  53. GRB010126 Optical Observations
  54. GRB010126 optical observations
  55. GRB010126: Optical observations
  56. IPN TRIANGULATION OF GRB010126
  57. IPN/RXTE TRIANGULATION OF GRB010126
  58. GRB 010119, optical observations
  59. GRB010119: Optical observations
  60. Optical Observations of GRB 001018 at Keck
  61. GRB010119, Radio observations
  62. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  63. Optical observations of GRB 001018 with JCAM
  64. IPN TRIANGULATION OF GRB010115
  65. IPN TRIANGULATION OF GRB010109
  66. IPN TRIANGULATION OF GRB010109
  67. GRB010103, optical observations
  68. IPN triangulation of GRB010104
  69. IPN triangulation of GRB010103
  70. GRB 001204: Ks observations
  71. H band observation of GRB 001212
  72. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  73. IPN triangulation of GRB001219
  74. GRB 001212 Optical Observation
  75. GRB 001212 Optical Observation
  76. GRB 001212 optical observation
  77. GRB 001212 possible OA in 2MASS
  78. GRB 001212 possible OA
  79. IPN triangulation of GRB001212
  80. GRB001204: Optical observations
  81. Confirmation of IPN position for GRB001204
  82. GRB001204, Radio observations
  83. IPN triangulation of GRB001204 (short/hard)
  84. GRB 001105, further optical observations
  85. GRB001120: Gunn-i observations
  86. GRB001120: Optical observations
  87. GRB001109, optical observations
  88. GRB001120, optical observations
  89. WSRT 4.8 GHz observations of GRB001109
  90. IPN triangulation of GRB001120
  91. Optical/NIR observations of GRB001109
  92. GRB 001109: deep JHK upper limits
  93. GRB 001109 X-ray afterglow with BeppoSAX
  94. CORRECTION to XMM-Newton observation of GRB001025
  95. GRB001109: Optical observations
  96. GRB001109: BeppoSAX/NFI Observations
  97. GRB001109, R-band optical observations
  98. GRB001109, Radio observations
  99. GRB001109: BeppoSAX refined WFC position
  100. BeppoSAX ALERT: GRB001109

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