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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"

39170 results found.

  1. GRB010222: possible optical counterpart
  2. GRB010222
  3. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  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 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 Optical Observation
  14. J-Band Observation of GRB 010214.
  15. GRB010213, Near-IR observations
  16. Possible InfraRed Transient of GRB 010214.
  17. GRB010214 Optical Observation
  18. GRB010214: BeppoSAX/NFI Observations
  19. GRB010213 (HETE) TAROT observations
  20. GRB 010214, optical observations
  21. BeppoSAX ALERT: GRB010214
  22. IPN Status Report
  23. HETE Status
  24. GRB010126 opt. obs.
  25. IPN/RXTE TRIANGULATION OF GRB010126
  26. GRB010126: CONCAM crude optical limits during GRB
  27. GRB010126, TNG R-band observations
  28. IPN TRIANGULATION OF GRB010126
  29. IPN/RXTE TRIANGULATION OF GRB010126
  30. GRB 010119, optical observations
  31. GRB010119: Optical observations
  32. Optical Observations of GRB 001018 at Keck
  33. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  34. Optical observations of GRB 001018 with JCAM
  35. IPN TRIANGULATION OF GRB010115
  36. IPN TRIANGULATION OF GRB010109
  37. GRB010103, optical observations
  38. IPN triangulation of GRB010104
  39. IPN triangulation of GRB010103
  40. GRB 001204: Ks observations
  41. H band observation of GRB 001212
  42. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  43. IPN triangulation of GRB001219
  44. GRB 001212 Optical Observation
  45. GRB 001212 Optical Observation
  46. GRB 001212 optical observation
  47. GRB 001212 possible OA in 2MASS
  48. GRB 001212 possible OA
  49. IPN triangulation of GRB001212
  50. Confirmation of IPN position for GRB001204
  51. IPN triangulation of GRB001204 (short/hard)
  52. GRB 001105, further optical observations
  53. GRB001120: Gunn-i observations
  54. GRB001120: Optical observations
  55. GRB001109, optical observations
  56. GRB001120, optical observations
  57. WSRT 4.8 GHz observations of GRB001109
  58. IPN triangulation of GRB001120
  59. Optical/NIR observations of GRB001109
  60. GRB 001109: deep JHK upper limits
  61. GRB 001109 X-ray afterglow with BeppoSAX
  62. GRB001109: Optical observations
  63. GRB001109: BeppoSAX/NFI Observations
  64. GRB001109, R-band optical observations
  65. GRB001109, Radio observations
  66. BeppoSAX ALERT: GRB001109
  67. GRB001105 BVRI field photometry correction
  68. GRB001105, BVRI field photometry
  69. GRB 001105, R-band observation
  70. IPN TRIANGULATION OF GRB001105
  71. GRB 001025B, Optical obervations
  72. GRB 991208: HST Imaging of the Host Galaxy
  73. GRB000926: R-image of the host galaxy
  74. GRB 001025B, I-band observations
  75. GRB 001025 Optical Observations
  76. GRB 001025A, optical observation
  77. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  78. IPN triangulation of GRB001025
  79. ASM Localization of GRB 001025
  80. GRB001007, Radio observations
  81. IPN TRIANGULATION OF GRB001020
  82. GRB001019, Optical Observations
  83. GRB 001018, Possible Radio Afterglow
  84. GRB001018, Gamma Ray Observations
  85. IPN TRIANGULATION OF GRB001019
  86. IPN TRIANGULATION OF GRB001018
  87. IPN TRIANGULATION OF GRB 001017
  88. GRB 000926: Improved Absorber Redshift
  89. V,R,I band observations of GRB000926
  90. The Likely Optical/Infrared Afterglow of GRB 001011
  91. HETE positions added to GCN
  92. BeppoSAX ALERT: GRB001011
  93. GRB 001007, BVR-band observations
  94. GRB000926 - Amateur Optical Observations
  95. GRB001007: Optical observations
  96. CONCAM null result on GRB001005
  97. IPN triangulation of GRB001007
  98. GRB 000926 : the host galaxy
  99. IPN triangulation of GRB001005
  100. GRB 000926 Chandra Observation

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