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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"

45450 results found.

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

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