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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"

18399 results found.

  1. GRB 050906: MARGE Optical Limits
  2. GRB 050906: Swift-BAT refined analysis
  3. GRB 050906: Swift XRT upper limit
  4. GRB050906: P60 Observations
  5. GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
  6. GRB 050906: Bright galaxy in BAT error box
  7. GRB 050906: Swift/BAT Detection of a possible burst
  8. GRB 050904: Swift/UVOT observations
  9. GRB 050904: early Swift XRT analysis results
  10. GRB 050904: BAT refined analysis of partial data set
  11. GRB050904: P60 Observations
  12. GRB 050904: TAROT optical limits
  13. GRB050904: Swift-BAT detection of a probable burst
  14. Swift-BAT triggers 153461-153465 are not GRBs
  15. Retraction of Swift-BAT trigger #153355
  16. GRB 050824: MDM Observations
  17. GRB 050827: Swift XRT preliminary analysis results
  18. Swift Trigger #152652 is not a GRB
  19. GRB050827: Swift/UVOT upper limits
  20. GRB 050827: Optical Limit
  21. GRB 050827: XRT possible afterglow detection
  22. GRB050827: RTT150 optical observations
  23. GRB 050827: Swift-BAT refined analysis
  24. GRB050827: Swift-BAT detection of a burst
  25. GRB 050826: Optical Candidate
  26. GRB050824, HETE-2 Observation
  27. GRB 050826: Swift XRT preliminary analysis results
  28. GRB 050826: BAT refined analysis
  29. GRB050826: Swift/UVOT early upper limits
  30. GRB050824: First 2 hours of power low optical decay?
  31. GRB 050826: Swift XRT position
  32. GRB050826: Swift-BAT detection of a long burst
  33. GRB050824: MASTER final analysis of the OT observations
  34. Possible GRB050825:MASTER optical observations
  35. Swift-BAT trigger 152038 is definitely not a GRB
  36. GRB050824: CORRECTION to UVOT observing times
  37. Swift-BAT trigger 152038 is probably not a GRB
  38. GRB050824: Swift/UVOT detection of fading afterglow
  39. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  40. GRB050824, I-band imaging
  41. GRB 050822: refined XRT analysis
  42. GRB 050824: XRT refined analysis and possible afterglow detection
  43. GRB 050824: BAT refined analysis of a soft weak burst
  44. GRB050824: MASTER:OT decay
  45. GRB050824: MASTER observation OT
  46. GRB050805a: MASTER optical candidat
  47. GRB 050824: ROTSE-III Optical Limits
  48. GRB050824: Swift-BAT detection of a burst
  49. GRB050822: Swift/UVOT upper limits
  50. GRB 050820A BAT observations of second, larger episode of emission
  51. GRB 050822: Swift-BAT refined analysis
  52. GRB 050820a - corrections to GCN 3846
  53. Swift/UVOT UV Photometry of GRB 050820B
  54. GRB 050822: ROTSE-III Prompt Optical Limits
  55. GRB 050822: Swift detection of a long burst
  56. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  57. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  58. GRB050820a BVRcIc field photometry
  59. GRB050820B XMM-Newton observation
  60. GRB 050820a: NIR Observations by WIRO
  61. GRB 050820B: Swift XRT position
  62. GRB050820B: Refined analysis of the Swift-BAT burst
  63. GRB050820B: BAT-Swift detection of a bright GRB
  64. Swift/UVOT photometry of GRB050820
  65. GRB050820: refined XRT analysis
  66. GRB 050820: Early RAPTOR detections
  67. GRB 050820 Swift-BAT refined analysis
  68. GRB050819: refined XRT analysis
  69. GRB 050820: Swift detection of a GRB
  70. GRB050820: Optical afterglow from P60
  71. GRB 050819 Swift-BAT refined analysis
  72. GRB050819: Swift XRT position
  73. GRB050819: Swift-BAT detection of a weak burst
  74. Swift-BAT trigger 150993 is not a GRB
  75. Swift Trigger 150823 is HETE J1900.1-2455
  76. GRB050817: Swift-BAT Detection of a burst
  77. GRB050815: Optical afterglow detection by Swift UVOT
  78. GRB050815: XRT refined analysis
  79. GRB050815: Refined analysis of the Swift-BAT burst
  80. GRB 050815: ROTSE-III Optical Limits
  81. GRB050815: Swift XRT afterglow localization
  82. GRB050815: Swift-BAT detection of a burst
  83. GRB050814: P60 Optical Afterglow Candidate
  84. GRB 050814: XRT refined analysis
  85. GRB050814: SWIFT/UVOT observation
  86. GRB050814: Refined analysis of the Swift-BAT burst
  87. GRB 050814: Swift XRT Afterglow Localization
  88. GRB 050814: Swift detection of a burst
  89. GRB050813, SDSS pre-burst observations
  90. GRB 050813: KAIT optical limit
  91. GRB 050813: Swift-BAT refined analysis
  92. GRB050813: SWIFT/UVOT observation
  93. GRB 050813: Swift XRT afterglow localization
  94. GRB 050813: Possible Short Swift-BAT GRB
  95. GRB050813 (Swift 150139): P60 Observations
  96. Swift-BAT trigger 150131 is not a GRB
  97. GRB050805b: CrAO optical limit
  98. GRB050805a : Null detection report
  99. Swift-BAT trigger 149118 is very likely not a GRB
  100. Retraction of Swift Trigger 149131 (GRB 050805B)

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