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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"

36053 results found.

  1. GRB010214: BeppoSAX WFC and GRBM preliminary data
  2. GRB 010214: X-Ray afterglow
  3. GRB 010214, Optical Observations
  4. GRB 010214 optical observation
  5. GRB010213 Optical Observation
  6. J-Band Observation of GRB 010214.
  7. GRB010213, Near-IR observations
  8. Possible InfraRed Transient of GRB 010214.
  9. GRB010214 Optical Observation
  10. GRB010214: BeppoSAX/NFI Observations
  11. GRB010213 (HETE) TAROT observations
  12. GRB 010214, optical observations
  13. BeppoSAX ALERT: GRB010214
  14. IPN Status Report
  15. HETE Status
  16. GRB010126 opt. obs.
  17. IPN/RXTE TRIANGULATION OF GRB010126
  18. GRB010126: CONCAM crude optical limits during GRB
  19. GRB010126, TNG R-band observations
  20. IPN TRIANGULATION OF GRB010126
  21. IPN/RXTE TRIANGULATION OF GRB010126
  22. GRB 010119, optical observations
  23. GRB010119: Optical observations
  24. Optical Observations of GRB 001018 at Keck
  25. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  26. Optical observations of GRB 001018 with JCAM
  27. IPN TRIANGULATION OF GRB010115
  28. IPN TRIANGULATION OF GRB010109
  29. GRB010103, optical observations
  30. IPN triangulation of GRB010104
  31. IPN triangulation of GRB010103
  32. GRB 001204: Ks observations
  33. H band observation of GRB 001212
  34. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  35. IPN triangulation of GRB001219
  36. GRB 001212 Optical Observation
  37. GRB 001212 Optical Observation
  38. GRB 001212 optical observation
  39. GRB 001212 possible OA in 2MASS
  40. GRB 001212 possible OA
  41. IPN triangulation of GRB001212
  42. Confirmation of IPN position for GRB001204
  43. IPN triangulation of GRB001204 (short/hard)
  44. GRB 001105, further optical observations
  45. GRB001120: Gunn-i observations
  46. GRB001120: Optical observations
  47. GRB001109, optical observations
  48. GRB001120, optical observations
  49. IPN triangulation of GRB001120
  50. Optical/NIR observations of GRB001109
  51. GRB 001109: deep JHK upper limits
  52. GRB 001109 X-ray afterglow with BeppoSAX
  53. GRB001109: Optical observations
  54. GRB001109: BeppoSAX/NFI Observations
  55. GRB001109, R-band optical observations
  56. GRB001109, Radio observations
  57. BeppoSAX ALERT: GRB001109
  58. GRB001105 BVRI field photometry correction
  59. GRB001105, BVRI field photometry
  60. GRB 001105, R-band observation
  61. IPN TRIANGULATION OF GRB001105
  62. GRB 001025B, Optical obervations
  63. GRB 991208: HST Imaging of the Host Galaxy
  64. GRB000926: R-image of the host galaxy
  65. GRB 001025B, I-band observations
  66. GRB 001025 Optical Observations
  67. GRB 001025A, optical observation
  68. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  69. IPN triangulation of GRB001025
  70. ASM Localization of GRB 001025
  71. GRB001007, Radio observations
  72. IPN TRIANGULATION OF GRB001020
  73. GRB001019, Optical Observations
  74. GRB 001018, Possible Radio Afterglow
  75. GRB001018, Gamma Ray Observations
  76. IPN TRIANGULATION OF GRB001019
  77. IPN TRIANGULATION OF GRB001018
  78. IPN TRIANGULATION OF GRB 001017
  79. GRB 000926: Improved Absorber Redshift
  80. V,R,I band observations of GRB000926
  81. The Likely Optical/Infrared Afterglow of GRB 001011
  82. HETE positions added to GCN
  83. BeppoSAX ALERT: GRB001011
  84. GRB 001007, BVR-band observations
  85. GRB000926 - Amateur Optical Observations
  86. CONCAM null result on GRB001005
  87. IPN triangulation of GRB001007
  88. GRB 000926 : the host galaxy
  89. IPN triangulation of GRB001005
  90. GRB 000926 Chandra Observation
  91. IPN triangulation of GRB 001004
  92. Public availability of BeppoSAX data of GRB000926
  93. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  94. GRB 000926, Optical Decay
  95. GRB000911: VLT infrared observation
  96. GRB000926 - Optical observations
  97. GRB000926 - Optical observations
  98. GRB 000926: optical observations
  99. GRB 000926, Optical Observations
  100. GRB000911: optical VLT observations

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