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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"

44354 results found.

  1. Redshift of the Optical Transient of GRB010222
  2. GRB010214B,Gamma Ray Observations
  3. GRB010222: possible optical counterpart
  4. GRB010222
  5. GRB010222: BeppoSAX refined position
  6. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  7. GRB010220, Radio and Optical Observations
  8. GRB 010220, simultaneous optical observations
  9. GRB010220: BeppoSAX WFC and GRBM preliminary data
  10. GRB010214, candidate optical afterglow
  11. GRB010214, optical observations
  12. BeppoSAX GRB010220: refined position
  13. BeppoSAX ALERT: GRB010220
  14. GRB010214: BeppoSAX WFC and GRBM preliminary data
  15. GRB 010214: X-Ray afterglow
  16. GRB 010214, Optical Observations
  17. GRB 010214 optical observation
  18. GRB010213, Radio Observations
  19. GRB010213 Optical Observation
  20. GRB010213, Radio Observations
  21. J-Band Observation of GRB 010214.
  22. GRB010214, Radio Observations
  23. GRB010214, optical observations
  24. GRB010213, optical observations
  25. GRB010213, Near-IR observations
  26. Possible InfraRed Transient of GRB 010214.
  27. GRB010214 Optical Observation
  28. GRB010214: BeppoSAX/NFI Observations
  29. GRB010213 (HETE) TAROT observations
  30. GRB 010214, optical observations
  31. GRB010213 detected by HETE
  32. GRB010214 refined WFC position
  33. BeppoSAX ALERT: GRB010214
  34. IPN Status Report
  35. HETE Status
  36. GRB010126 opt. obs.
  37. IPN/RXTE TRIANGULATION OF GRB010126
  38. GRB010126: CONCAM crude optical limits during GRB
  39. GRB010126, TNG R-band observations
  40. GRB010126 Optical Observations
  41. GRB010126 optical observations
  42. GRB010126: Optical observations
  43. IPN TRIANGULATION OF GRB010126
  44. IPN/RXTE TRIANGULATION OF GRB010126
  45. GRB 010119, optical observations
  46. GRB010119: Optical observations
  47. Optical Observations of GRB 001018 at Keck
  48. GRB010119, Radio observations
  49. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  50. Optical observations of GRB 001018 with JCAM
  51. IPN TRIANGULATION OF GRB010115
  52. IPN TRIANGULATION OF GRB010109
  53. IPN TRIANGULATION OF GRB010109
  54. GRB010103, optical observations
  55. IPN triangulation of GRB010104
  56. IPN triangulation of GRB010103
  57. GRB 001204: Ks observations
  58. H band observation of GRB 001212
  59. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  60. IPN triangulation of GRB001219
  61. GRB 001212 Optical Observation
  62. GRB 001212 Optical Observation
  63. GRB 001212 optical observation
  64. GRB 001212 possible OA in 2MASS
  65. GRB 001212 possible OA
  66. IPN triangulation of GRB001212
  67. GRB001204: Optical observations
  68. Confirmation of IPN position for GRB001204
  69. GRB001204, Radio observations
  70. IPN triangulation of GRB001204 (short/hard)
  71. GRB 001105, further optical observations
  72. GRB001120: Gunn-i observations
  73. GRB001120: Optical observations
  74. GRB001109, optical observations
  75. GRB001120, optical observations
  76. WSRT 4.8 GHz observations of GRB001109
  77. IPN triangulation of GRB001120
  78. Optical/NIR observations of GRB001109
  79. GRB 001109: deep JHK upper limits
  80. GRB 001109 X-ray afterglow with BeppoSAX
  81. CORRECTION to XMM-Newton observation of GRB001025
  82. GRB001109: Optical observations
  83. GRB001109: BeppoSAX/NFI Observations
  84. GRB001109, R-band optical observations
  85. GRB001109, Radio observations
  86. GRB001109: BeppoSAX refined WFC position
  87. BeppoSAX ALERT: GRB001109
  88. GRB001105, BVRI field photometry
  89. GRB 001105, R-band observation
  90. IPN TRIANGULATION OF GRB001105
  91. GRB 001025B, Optical obervations
  92. GRB 991208: HST Imaging of the Host Galaxy
  93. GRB000926: R-image of the host galaxy
  94. GRB 001025B, I-band observations
  95. XMM-Newton observation of GRB001025
  96. GRB001025B, Radio observations
  97. GRB 001025 Optical Observations
  98. GRB 001025A, optical observation
  99. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  100. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025

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