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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"

14824 results found.

  1. GRB 050803: RTT150 optical observations
  2. GRB050730: Radio Detection
  3. GRB 050802.422: Fading of the afterglow and detection of the host
  4. GRB050803: MASTER further analys
  5. GRB050803: MASTER optical observations
  6. GRB050803: Swift-BAT detection of a very long burst
  7. GCN GRB observation 050713A
  8. GRB 050802: Swift/UVOT optical and UV detections
  9. GRB050802 radio non-detection
  10. GRB 050802: Swift/UVOT observations
  11. GRB050801: Swift-BAT detection of a burst
  12. GRB 050801: ROTSE-III Detection of Possible Counterpart
  13. Swift/UVOT photometry of GRB050730
  14. GRB050730: Swift-BAT detection of a weak burst
  15. GRB050726: Swift UVOT observations
  16. GRB050726: Swift-BAT detection of a weak burst
  17. GRB 050724: J-band observations
  18. RXTE ASM Detection of GRB050724
  19. GRB050721A: Swift-BAT detection of a weak burst
  20. Swift-BAT detection of a possible GRB
  21. GRB050717
  22. Swift detection of GRB 050717
  23. GRB 050716 - UKIRT identification of candidate afterglow
  24. GRB050716: Faulkes North Telescope observation
  25. Swift/BAT detection of GRB 050716
  26. GRB 050715: Swift-BAT detection
  27. Swift detection of a long transient (GRB 050714B?)
  28. GRB 050709: optical afterglow candidate
  29. GRB 050713A: RAPTOR detection of early optical emission
  30. GRB050712: Swift UVOT Observation of Afterglow Emission
  31. GRB050713B: Faulkes North Telescope observation
  32. GRB050709: Candidate X-ray Afterglow from Chandra
  33. GRB 050713, R-band observations at NOT
  34. GRB 050713: Swift detection of Bright Burst
  35. GRB 050709: Swift UVOT and XRT observations
  36. GRB 050712: Swift detection of a weak burst
  37. GRB 050701
  38. GRB 050701, optical observations
  39. Swift trigger 143708 is really GRB 050701
  40. XRF050509c: Radio Detection
  41. GRB 050416(a): Host Galaxy Redshift Determination
  42. GRB050607: refined analysis of prompt REM observations
  43. GRB 050525a, Mid-Infrared Observations
  44. GRB050607: Swift Detection of a long GRB
  45. Limits on a SN in the field of GRB 050509b
  46. GRB050603: Radio Detection
  47. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  48. Swift/BAT Detection of GRB050603
  49. Possible GRB050528: no candidate from Liverpool Telescope
  50. Swift-BAT detection of possible GRB 050528
  51. GRB050306: optical afterglow not confirmed
  52. GRB 050525: BART optical observation
  53. INTEGRAL detection of GRB 050525
  54. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  55. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  56. Swift UVOT Observations of GRB 050520
  57. XRF050509C: Chandra Afterglow Detection
  58. GRB 050520: OSN optical observations
  59. XRF 050509C: REM NIR and Optical refined analysis
  60. GRB 050504: Swift XRT afterglow candidate has faded
  61. GRB050502b: Early Observation
  62. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  63. GRB 050509b: optical observations
  64. Swift Detection of GRB050509b: A short duration burst
  65. Swift Detection of the Burst GRB050509
  66. Swift-BAT detection of GRB 050507
  67. GRB 050505: early time observations
  68. GRB 050505: Further Swift UVOT observations.
  69. Swift-BAT detection of GRB050505
  70. Swift Detection of the Bright Burst GRB050502b
  71. GRB 050502: PAIRITEL IR Observations
  72. GRB 050502: ROTSE-III Detection of Possible Counterpart
  73. Swift-BAT Trigger 115881 is not a real GRB
  74. Swift/BAT possible detection of a weak burst GRB050430
  75. GRB050416a: Radio Detection
  76. Swift Detection of GRB 050422
  77. GRB 050416: Optical/NIR observations
  78. GRB050421: Radio Observations
  79. GRB050421: Radio Observations
  80. GRB050421
  81. GRB 050421: Optical observations at the INT
  82. Swift Detection of GRB050421
  83. Swift-BAT detection of the bright and long GRB 050418
  84. GRB 050416B: optical observations
  85. Swift-BAT detection of GRB 050416b
  86. GRB 050416: Swift/UVOT detection of afterglow emission
  87. GRB 050416: KAIT observations
  88. Swift BAT/XRT Detection of GRB 050416
  89. GRB 050412: Subaru observations
  90. GRB 050412: optical observations
  91. GRB 050408: refined XRT analysis, no jet break seen yet
  92. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  93. GRB 050412: IR Observations
  94. GRB 050408: PROMPT VRcIc Observations
  95. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  96. GRB050410 : Null detection report
  97. Swift-BAT detection of GRB 050410
  98. GRB 050408: Mercator Optical Observations
  99. GRB 050408 optical candidate
  100. GRB050401: Radio Detection

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