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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"

18397 results found.

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

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