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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. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  2. GRB010220, Radio and Optical Observations
  3. GRB 010220, simultaneous optical observations
  4. GRB010220: BeppoSAX WFC and GRBM preliminary data
  5. GRB010214, candidate optical afterglow
  6. GRB010214, optical observations
  7. BeppoSAX GRB010220: refined position
  8. BeppoSAX ALERT: GRB010220
  9. GRB010214: BeppoSAX WFC and GRBM preliminary data
  10. GRB 010214: X-Ray afterglow
  11. GRB 010214, Optical Observations
  12. GRB 010214 optical observation
  13. GRB010213, Radio Observations
  14. GRB010213 Optical Observation
  15. GRB010213, Radio Observations
  16. J-Band Observation of GRB 010214.
  17. GRB010214, Radio Observations
  18. GRB010214, optical observations
  19. GRB010213, optical observations
  20. GRB010213, Near-IR observations
  21. Possible InfraRed Transient of GRB 010214.
  22. GRB010214 Optical Observation
  23. GRB010214: BeppoSAX/NFI Observations
  24. GRB010213 (HETE) TAROT observations
  25. GRB 010214, optical observations
  26. GRB010213 detected by HETE
  27. GRB010214 refined WFC position
  28. BeppoSAX ALERT: GRB010214
  29. IPN Status Report
  30. HETE Status
  31. GRB010126 opt. obs.
  32. IPN/RXTE TRIANGULATION OF GRB010126
  33. GRB010126: CONCAM crude optical limits during GRB
  34. GRB010126, TNG R-band observations
  35. GRB010126 Optical Observations
  36. GRB010126 optical observations
  37. GRB010126: Optical observations
  38. IPN TRIANGULATION OF GRB010126
  39. IPN/RXTE TRIANGULATION OF GRB010126
  40. GRB 010119, optical observations
  41. GRB010119: Optical observations
  42. Optical Observations of GRB 001018 at Keck
  43. GRB010119, Radio observations
  44. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  45. Optical observations of GRB 001018 with JCAM
  46. IPN TRIANGULATION OF GRB010115
  47. IPN TRIANGULATION OF GRB010109
  48. IPN TRIANGULATION OF GRB010109
  49. GRB010103, optical observations
  50. IPN triangulation of GRB010104
  51. IPN triangulation of GRB010103
  52. GRB 001204: Ks observations
  53. H band observation of GRB 001212
  54. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  55. IPN triangulation of GRB001219
  56. GRB 001212 Optical Observation
  57. GRB 001212 Optical Observation
  58. GRB 001212 optical observation
  59. GRB 001212 possible OA in 2MASS
  60. GRB 001212 possible OA
  61. IPN triangulation of GRB001212
  62. GRB001204: Optical observations
  63. Confirmation of IPN position for GRB001204
  64. GRB001204, Radio observations
  65. IPN triangulation of GRB001204 (short/hard)
  66. GRB 001105, further optical observations
  67. GRB001120: Gunn-i observations
  68. GRB001120: Optical observations
  69. GRB001109, optical observations
  70. GRB001120, optical observations
  71. WSRT 4.8 GHz observations of GRB001109
  72. IPN triangulation of GRB001120
  73. Optical/NIR observations of GRB001109
  74. GRB 001109: deep JHK upper limits
  75. GRB 001109 X-ray afterglow with BeppoSAX
  76. CORRECTION to XMM-Newton observation of GRB001025
  77. GRB001109: Optical observations
  78. GRB001109: BeppoSAX/NFI Observations
  79. GRB001109, R-band optical observations
  80. GRB001109, Radio observations
  81. GRB001109: BeppoSAX refined WFC position
  82. BeppoSAX ALERT: GRB001109
  83. GRB001105 BVRI field photometry correction
  84. GRB001105, BVRI field photometry
  85. GRB 001105, R-band observation
  86. IPN TRIANGULATION OF GRB001105
  87. GRB 001025B, Optical obervations
  88. GRB 991208: HST Imaging of the Host Galaxy
  89. GRB000926: R-image of the host galaxy
  90. GRB 001025B, I-band observations
  91. XMM-Newton observation of GRB001025
  92. GRB001025B, Radio observations
  93. GRB 001025 Optical Observations
  94. GRB 001025A, optical observation
  95. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  96. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  97. IPN triangulation of GRB001025
  98. GRB001007: Optical observations
  99. ASM Localization of GRB 001025
  100. GRB001007, Radio observations

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