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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"
  1. GRB050509c: REM NIR and Optical observations (errata corrige to GCN 3400)
  2. GRB 050505, early TAROT observation
  3. GRB050509c (=H3751): An X-Ray Flash Localized By HETE
  4. GRB 050509b: Further Analysis of Keck LRIS Images
  5. GRB050509c: REM NIR and Optical observations
  6. GRB 050509b: Physical Properties of the Candidate Host galaxy
  7. GRB 050505: SARA Observations
  8. Swift UVOT Follow-up Observations of GRB 050509B
  9. GRB 050509B, Optical Observations
  10. GRB 050509B: Swift/XRT refined analysis
  11. GRB050509a: Swift UVOT observations
  12. GRB 050509b: Optical observations
  13. GRB 050509b: Precision Astrometry
  14. GRB 050509b: Possible Optical Counterpart
  15. Keck/DEIMOS Spectrum of Possible Host Galaxy for GRB050509b
  16. GRB 050509A: Optical observations
  17. GRB 050509b: Optical Counterpart Candidate
  18. GRB050509b: Radio Observations
  19. GRB 050509b: PAIRITEL and WIYN Observations
  20. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  21. GRB 050509b: optical observations
  22. GRB 050509b: Swift XRT Position
  23. GRB 050509B: ROTSE-III Optical Limits
  24. Swift Detection of GRB050509b: A short duration burst
  25. GRB 050509a: Swift XRT Position
  26. Swift Detection of the Burst GRB050509
  27. Swift-BAT detection of GRB 050507
  28. GRB 050505: Keck I-band Magnitude
  29. GRB 050505: early time observations
  30. GRB 050505 - Faulkes Telescope North observations
  31. GRB 050502a: Swift XRT Upper Limit
  32. GRB 050505, simultaneous optical observation
  33. GRB050505: Infrared observations
  34. GRB 050505: Further Swift UVOT observations.
  35. GRB050505: AAVSO observations
  36. GRB050416A : 1 GHz limit from GMRT
  37. GRB 050505: Keck absorption spectrum and redshift (z=4.27)
  38. GRB 050505 UVOT
  39. GRB050505: Optical Afterglow Candidate
  40. GRB 050505: Swift XRT Position
  41. GRB050505 Swift-BAT refined analysis
  42. GRB 050502a: Optical Observations
  43. GRB 050416b:Swift XRT afterglow upper limits
  44. GRB 050416b:Swift XRT afterglow upper limits
  45. Swift-BAT detection of GRB050505
  46. GRB 050504: Swift XRT position
  47. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  48. GRB050502b: Afterglow Confirmation
  49. GRB050502: P200 Observations (Correction)
  50. GRB050502: P200 Observations
  51. GRB 050504 : R band observation at Lulin observatory
  52. Swift UVOT observation of GRB 050504
  53. GRB 050504, R band Observations
  54. GRB050504: Faulkes North optical robotic limit
  55. GRB 050502b, V band Observations
  56. GRB050504: P60 Observations
  57. GRB 050504: A long GRB detected with INTEGRAL
  58. GRB (?) 050504: IR Observations, Intriguing Source
  59. GRB 050502b, Optical observations
  60. GRB050502a: P60 Observations (Correction)
  61. GRB050502a: P60 Observations
  62. Renewal of SGR 1806-20 activity
  63. GRB 050502a: RBO Observations
  64. GRB 050502A: WSRT Radio Observations
  65. GRB050502A: Optical Observations
  66. GRB050502B Swift-BAT refined analysis
  67. GRB050502B: I band source in XRT error circle
  68. Swift UVOT refined analysis
  69. Retraction of Swift-BAT trigger 116145
  70. GRB 050502a : R band observation at Lulin observatory
  71. GRB 050502b : optical observation at Lulin observatory
  72. GRB 050502b: Swift XRT Position
  73. GRB 050502A: Redshift measurement based on Keck HIRES Observations
  74. GRB050502B: Optical Limits from ANU 1m
  75. Swift Detection of the Bright Burst GRB050502b
  76. GRB 050502: INTEGRAL results
  77. GRB050502: ANU 1m optical Observations
  78. GRB 050502: Confirmed variability of the afterglow candidate +
  79. GRB 050502: PAIRITEL IR Observations
  80. GRB050502 - Correction on the Optical Candidate from the Liverpool
  81. GRB050502 - Optical Candidate from the Liverpool Telescope
  82. GRB 050502 - A long GRB detected with INTEGRAL
  83. GRB 050502: ROTSE-III Detection of Possible Counterpart
  84. Swift-BAT Trigger 115881 is not a real GRB
  85. Swift/BAT possible detection of a weak burst GRB050430
  86. GRB 050401: Rc observation
  87. GRB050416a: Radio Detection
  88. GRB 050422: Swift-UVOT observation
  89. GRB 050422: Swift-BAT refined analysis
  90. GRB 050422: Swift XRT Position
  91. Swift Detection of GRB 050422
  92. GRB 050421: NIR observations
  93. GRB 050416: Optical/NIR observations
  94. GRB 050421: SLOTIS observations
  95. GRB 050421: Further Analysis of IR imaging
  96. GRB050421: Radio Observations
  97. GRB050421: Radio Observations
  98. GRB 050421: Swift-UVOT observation
  99. GRB 050421: IR Observations
  100. GRB 050421: Swift-BAT refined analysis

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