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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"

35262 results found.

  1. GRB 010214, Optical Observations
  2. GRB010222: Sub-millimeter detection
  3. GRB010222: R-band fading behavior
  4. GRB010222: Optical Observations
  5. GRB010222, optical observations
  6. GRB010222: BeppoSAX/NFI Observations
  7. Redshift of the Optical Transient of GRB010222
  8. GRB010214B,Gamma Ray Observations
  9. GRB010222
  10. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  11. GRB 010220, simultaneous optical observations
  12. GRB010220: BeppoSAX WFC and GRBM preliminary data
  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 Optical Observation
  19. J-Band Observation of GRB 010214.
  20. GRB010213, Near-IR observations
  21. Possible InfraRed Transient of GRB 010214.
  22. GRB010214 Optical Observation
  23. GRB010214: BeppoSAX/NFI Observations
  24. GRB010213 (HETE) TAROT observations
  25. GRB 010214, optical observations
  26. BeppoSAX ALERT: GRB010214
  27. IPN Status Report
  28. HETE Status
  29. GRB010126 opt. obs.
  30. IPN/RXTE TRIANGULATION OF GRB010126
  31. GRB010126: CONCAM crude optical limits during GRB
  32. GRB010126, TNG R-band observations
  33. IPN TRIANGULATION OF GRB010126
  34. IPN/RXTE TRIANGULATION OF GRB010126
  35. GRB 010119, optical observations
  36. GRB010119: Optical observations
  37. Optical Observations of GRB 001018 at Keck
  38. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  39. Optical observations of GRB 001018 with JCAM
  40. IPN TRIANGULATION OF GRB010115
  41. IPN TRIANGULATION OF GRB010109
  42. GRB010103, optical observations
  43. IPN triangulation of GRB010104
  44. IPN triangulation of GRB010103
  45. GRB 001204: Ks observations
  46. H band observation of GRB 001212
  47. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  48. IPN triangulation of GRB001219
  49. GRB 001212 Optical Observation
  50. GRB 001212 Optical Observation
  51. GRB 001212 optical observation
  52. GRB 001212 possible OA in 2MASS
  53. GRB 001212 possible OA
  54. IPN triangulation of GRB001212
  55. Confirmation of IPN position for GRB001204
  56. IPN triangulation of GRB001204 (short/hard)
  57. GRB 001105, further optical observations
  58. GRB001120: Gunn-i observations
  59. GRB001120: Optical observations
  60. GRB001109, optical observations
  61. GRB001120, optical observations
  62. IPN triangulation of GRB001120
  63. Optical/NIR observations of GRB001109
  64. GRB 001109: deep JHK upper limits
  65. GRB 001109 X-ray afterglow with BeppoSAX
  66. GRB001109: Optical observations
  67. GRB001109: BeppoSAX/NFI Observations
  68. GRB001109, R-band optical observations
  69. GRB001109, Radio observations
  70. BeppoSAX ALERT: GRB001109
  71. GRB001105 BVRI field photometry correction
  72. GRB001105, BVRI field photometry
  73. GRB 001105, R-band observation
  74. IPN TRIANGULATION OF GRB001105
  75. GRB 001025B, Optical obervations
  76. GRB 991208: HST Imaging of the Host Galaxy
  77. GRB000926: R-image of the host galaxy
  78. GRB 001025B, I-band observations
  79. GRB 001025 Optical Observations
  80. GRB 001025A, optical observation
  81. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  82. IPN triangulation of GRB001025
  83. ASM Localization of GRB 001025
  84. GRB001007, Radio observations
  85. IPN TRIANGULATION OF GRB001020
  86. GRB001019, Optical Observations
  87. GRB 001018, Possible Radio Afterglow
  88. GRB001018, Gamma Ray Observations
  89. IPN TRIANGULATION OF GRB001019
  90. IPN TRIANGULATION OF GRB001018
  91. IPN TRIANGULATION OF GRB 001017
  92. GRB 000926: Improved Absorber Redshift
  93. V,R,I band observations of GRB000926
  94. The Likely Optical/Infrared Afterglow of GRB 001011
  95. HETE positions added to GCN
  96. BeppoSAX ALERT: GRB001011
  97. GRB 001007, BVR-band observations
  98. GRB000926 - Amateur Optical Observations
  99. CONCAM null result on GRB001005
  100. IPN triangulation of GRB001007

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