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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"

19193 results found.

  1. GRB 050906: Swift/BAT Detection of a possible burst
  2. GRB 050904: Swift/UVOT observations
  3. GRB 050904: early Swift XRT analysis results
  4. GRB 050904: BAT refined analysis of partial data set
  5. GRB050904: P60 Observations
  6. GRB 050904: TAROT optical limits
  7. GRB050904: Swift-BAT detection of a probable burst
  8. Swift-BAT triggers 153461-153465 are not GRBs
  9. Retraction of Swift-BAT trigger #153355
  10. GRB 050824: MDM Observations
  11. GRB 050827: Swift XRT preliminary analysis results
  12. Swift Trigger #152652 is not a GRB
  13. GRB050827: Swift/UVOT upper limits
  14. GRB 050827: Optical Limit
  15. GRB 050827: XRT possible afterglow detection
  16. GRB050827: RTT150 optical observations
  17. GRB 050827: Swift-BAT refined analysis
  18. GRB050827: Swift-BAT detection of a burst
  19. GRB 050826: Optical Candidate
  20. GRB050824, HETE-2 Observation
  21. GRB 050826: Swift XRT preliminary analysis results
  22. GRB 050826: BAT refined analysis
  23. GRB050826: Swift/UVOT early upper limits
  24. GRB050824: First 2 hours of power low optical decay?
  25. GRB 050826: Swift XRT position
  26. GRB050826: Swift-BAT detection of a long burst
  27. GRB050824: MASTER final analysis of the OT observations
  28. Possible GRB050825:MASTER optical observations
  29. Swift-BAT trigger 152038 is definitely not a GRB
  30. GRB050824: CORRECTION to UVOT observing times
  31. Swift-BAT trigger 152038 is probably not a GRB
  32. GRB050824: Swift/UVOT detection of fading afterglow
  33. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  34. GRB050824, I-band imaging
  35. GRB 050822: refined XRT analysis
  36. GRB 050824: XRT refined analysis and possible afterglow detection
  37. GRB 050824: BAT refined analysis of a soft weak burst
  38. GRB050824: MASTER:OT decay
  39. GRB050824: MASTER observation OT
  40. GRB050805a: MASTER optical candidat
  41. GRB 050824: ROTSE-III Optical Limits
  42. GRB050824: Swift-BAT detection of a burst
  43. GRB050822: Swift/UVOT upper limits
  44. GRB 050820A BAT observations of second, larger episode of emission
  45. GRB 050822: Swift-BAT refined analysis
  46. GRB 050820a - corrections to GCN 3846
  47. Swift/UVOT UV Photometry of GRB 050820B
  48. GRB 050822: ROTSE-III Prompt Optical Limits
  49. GRB 050822: Swift detection of a long burst
  50. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  51. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  52. GRB050820a BVRcIc field photometry
  53. GRB050820B XMM-Newton observation
  54. GRB 050820a: NIR Observations by WIRO
  55. GRB 050820B: Swift XRT position
  56. GRB050820B: Refined analysis of the Swift-BAT burst
  57. GRB050820B: BAT-Swift detection of a bright GRB
  58. Swift/UVOT photometry of GRB050820
  59. GRB050820: refined XRT analysis
  60. GRB 050820: Early RAPTOR detections
  61. GRB 050820 Swift-BAT refined analysis
  62. GRB050819: refined XRT analysis
  63. GRB 050820: Swift detection of a GRB
  64. GRB050820: Optical afterglow from P60
  65. GRB 050819 Swift-BAT refined analysis
  66. GRB050819: Swift XRT position
  67. GRB050819: Swift-BAT detection of a weak burst
  68. Swift-BAT trigger 150993 is not a GRB
  69. Swift Trigger 150823 is HETE J1900.1-2455
  70. GRB050817: Swift-BAT Detection of a burst
  71. GRB050815: Optical afterglow detection by Swift UVOT
  72. GRB050815: XRT refined analysis
  73. GRB050815: Refined analysis of the Swift-BAT burst
  74. GRB 050815: ROTSE-III Optical Limits
  75. GRB050815: Swift XRT afterglow localization
  76. GRB050815: Swift-BAT detection of a burst
  77. GRB050814: P60 Optical Afterglow Candidate
  78. GRB 050814: XRT refined analysis
  79. GRB050814: SWIFT/UVOT observation
  80. GRB050814: Refined analysis of the Swift-BAT burst
  81. GRB 050814: Swift XRT Afterglow Localization
  82. GRB 050814: Swift detection of a burst
  83. GRB050813, SDSS pre-burst observations
  84. GRB 050813: KAIT optical limit
  85. GRB 050813: Swift-BAT refined analysis
  86. GRB050813: SWIFT/UVOT observation
  87. GRB 050813: Swift XRT afterglow localization
  88. GRB 050813: Possible Short Swift-BAT GRB
  89. GRB050813 (Swift 150139): P60 Observations
  90. Swift-BAT trigger 150131 is not a GRB
  91. GRB050805b: CrAO optical limit
  92. GRB050805a : Null detection report
  93. Swift-BAT trigger 149118 is very likely not a GRB
  94. Retraction of Swift Trigger 149131 (GRB 050805B)
  95. GRB 050805b: OHP optical limits
  96. GRB 050805b: TAROT optical limits
  97. GRB050805b: MASTER optical observations
  98. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  99. GRB050805a: MASTER optical candidat
  100. Swift-BAT trigger 149118 is probably not a GRB

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