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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"

19020 results found.

  1. GRB 050904: early Swift XRT analysis results
  2. GRB 050904: BAT refined analysis of partial data set
  3. GRB050904: P60 Observations
  4. GRB 050904: TAROT optical limits
  5. GRB050904: Swift-BAT detection of a probable burst
  6. Swift-BAT triggers 153461-153465 are not GRBs
  7. Retraction of Swift-BAT trigger #153355
  8. GRB 050824: MDM Observations
  9. GRB 050827: Swift XRT preliminary analysis results
  10. Swift Trigger #152652 is not a GRB
  11. GRB050827: Swift/UVOT upper limits
  12. GRB 050827: Optical Limit
  13. GRB 050827: XRT possible afterglow detection
  14. GRB050827: RTT150 optical observations
  15. GRB 050827: Swift-BAT refined analysis
  16. GRB050827: Swift-BAT detection of a burst
  17. GRB 050826: Optical Candidate
  18. GRB050824, HETE-2 Observation
  19. GRB 050826: Swift XRT preliminary analysis results
  20. GRB 050826: BAT refined analysis
  21. GRB050826: Swift/UVOT early upper limits
  22. GRB050824: First 2 hours of power low optical decay?
  23. GRB 050826: Swift XRT position
  24. GRB050826: Swift-BAT detection of a long burst
  25. GRB050824: MASTER final analysis of the OT observations
  26. Possible GRB050825:MASTER optical observations
  27. Swift-BAT trigger 152038 is definitely not a GRB
  28. GRB050824: CORRECTION to UVOT observing times
  29. Swift-BAT trigger 152038 is probably not a GRB
  30. GRB050824: Swift/UVOT detection of fading afterglow
  31. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  32. GRB050824, I-band imaging
  33. GRB 050822: refined XRT analysis
  34. GRB 050824: XRT refined analysis and possible afterglow detection
  35. GRB 050824: BAT refined analysis of a soft weak burst
  36. GRB050824: MASTER:OT decay
  37. GRB050824: MASTER observation OT
  38. GRB050805a: MASTER optical candidat
  39. GRB 050824: ROTSE-III Optical Limits
  40. GRB050824: Swift-BAT detection of a burst
  41. GRB050822: Swift/UVOT upper limits
  42. GRB 050820A BAT observations of second, larger episode of emission
  43. GRB 050822: Swift-BAT refined analysis
  44. GRB 050820a - corrections to GCN 3846
  45. Swift/UVOT UV Photometry of GRB 050820B
  46. GRB 050822: ROTSE-III Prompt Optical Limits
  47. GRB 050822: Swift detection of a long burst
  48. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  49. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  50. GRB050820a BVRcIc field photometry
  51. GRB050820B XMM-Newton observation
  52. GRB 050820a: NIR Observations by WIRO
  53. GRB 050820B: Swift XRT position
  54. GRB050820B: Refined analysis of the Swift-BAT burst
  55. GRB050820B: BAT-Swift detection of a bright GRB
  56. Swift/UVOT photometry of GRB050820
  57. GRB050820: refined XRT analysis
  58. GRB 050820: Early RAPTOR detections
  59. GRB 050820 Swift-BAT refined analysis
  60. GRB050819: refined XRT analysis
  61. GRB 050820: Swift detection of a GRB
  62. GRB050820: Optical afterglow from P60
  63. GRB 050819 Swift-BAT refined analysis
  64. GRB050819: Swift XRT position
  65. GRB050819: Swift-BAT detection of a weak burst
  66. Swift-BAT trigger 150993 is not a GRB
  67. Swift Trigger 150823 is HETE J1900.1-2455
  68. GRB050817: Swift-BAT Detection of a burst
  69. GRB050815: Optical afterglow detection by Swift UVOT
  70. GRB050815: XRT refined analysis
  71. GRB050815: Refined analysis of the Swift-BAT burst
  72. GRB 050815: ROTSE-III Optical Limits
  73. GRB050815: Swift XRT afterglow localization
  74. GRB050815: Swift-BAT detection of a burst
  75. GRB050814: P60 Optical Afterglow Candidate
  76. GRB 050814: XRT refined analysis
  77. GRB050814: SWIFT/UVOT observation
  78. GRB050814: Refined analysis of the Swift-BAT burst
  79. GRB 050814: Swift XRT Afterglow Localization
  80. GRB 050814: Swift detection of a burst
  81. GRB050813, SDSS pre-burst observations
  82. GRB 050813: KAIT optical limit
  83. GRB 050813: Swift-BAT refined analysis
  84. GRB050813: SWIFT/UVOT observation
  85. GRB 050813: Swift XRT afterglow localization
  86. GRB 050813: Possible Short Swift-BAT GRB
  87. GRB050813 (Swift 150139): P60 Observations
  88. Swift-BAT trigger 150131 is not a GRB
  89. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  90. Detection of an intermediate burst from SGR 1806-20 on August 8
  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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