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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"

45448 results found.

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