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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"

18685 results found.

  1. Retraction of Swift-BAT trigger #153355
  2. GRB 050824: MDM Observations
  3. GRB 050827: Swift XRT preliminary analysis results
  4. Swift Trigger #152652 is not a GRB
  5. GRB050827: Swift/UVOT upper limits
  6. GRB 050827: Optical Limit
  7. GRB 050827: XRT possible afterglow detection
  8. GRB050827: RTT150 optical observations
  9. GRB 050827: Swift-BAT refined analysis
  10. GRB050827: Swift-BAT detection of a burst
  11. GRB 050826: Optical Candidate
  12. GRB050824, HETE-2 Observation
  13. GRB 050826: Swift XRT preliminary analysis results
  14. GRB 050826: BAT refined analysis
  15. GRB050826: Swift/UVOT early upper limits
  16. GRB050824: First 2 hours of power low optical decay?
  17. GRB 050826: Swift XRT position
  18. GRB050826: Swift-BAT detection of a long burst
  19. GRB050824: MASTER final analysis of the OT observations
  20. Possible GRB050825:MASTER optical observations
  21. Swift-BAT trigger 152038 is definitely not a GRB
  22. GRB050824: CORRECTION to UVOT observing times
  23. Swift-BAT trigger 152038 is probably not a GRB
  24. GRB050824: Swift/UVOT detection of fading afterglow
  25. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  26. GRB050824, I-band imaging
  27. GRB 050822: refined XRT analysis
  28. GRB 050824: XRT refined analysis and possible afterglow detection
  29. GRB 050824: BAT refined analysis of a soft weak burst
  30. GRB050824: MASTER:OT decay
  31. GRB050824: MASTER observation OT
  32. GRB050805a: MASTER optical candidat
  33. GRB 050824: ROTSE-III Optical Limits
  34. GRB050824: Swift-BAT detection of a burst
  35. GRB050822: Swift/UVOT upper limits
  36. GRB 050820A BAT observations of second, larger episode of emission
  37. GRB 050822: Swift-BAT refined analysis
  38. GRB 050820a - corrections to GCN 3846
  39. Swift/UVOT UV Photometry of GRB 050820B
  40. GRB 050822: ROTSE-III Prompt Optical Limits
  41. GRB 050822: Swift detection of a long burst
  42. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  43. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  44. GRB050820a BVRcIc field photometry
  45. GRB050820B XMM-Newton observation
  46. GRB 050820a: NIR Observations by WIRO
  47. GRB 050820B: Swift XRT position
  48. GRB050820B: Refined analysis of the Swift-BAT burst
  49. GRB050820B: BAT-Swift detection of a bright GRB
  50. Swift/UVOT photometry of GRB050820
  51. GRB050820: refined XRT analysis
  52. GRB 050820: Early RAPTOR detections
  53. GRB 050820 Swift-BAT refined analysis
  54. GRB050819: refined XRT analysis
  55. GRB 050820: Swift detection of a GRB
  56. GRB050820: Optical afterglow from P60
  57. GRB 050819 Swift-BAT refined analysis
  58. GRB050819: Swift XRT position
  59. GRB050819: Swift-BAT detection of a weak burst
  60. Swift-BAT trigger 150993 is not a GRB
  61. Swift Trigger 150823 is HETE J1900.1-2455
  62. GRB050817: Swift-BAT Detection of a burst
  63. GRB050815: Optical afterglow detection by Swift UVOT
  64. GRB050815: XRT refined analysis
  65. GRB050815: Refined analysis of the Swift-BAT burst
  66. GRB 050815: ROTSE-III Optical Limits
  67. GRB050815: Swift XRT afterglow localization
  68. GRB050815: Swift-BAT detection of a burst
  69. GRB050814: P60 Optical Afterglow Candidate
  70. GRB 050814: XRT refined analysis
  71. GRB050814: SWIFT/UVOT observation
  72. GRB050814: Refined analysis of the Swift-BAT burst
  73. GRB 050814: Swift XRT Afterglow Localization
  74. GRB 050814: Swift detection of a burst
  75. GRB050813, SDSS pre-burst observations
  76. GRB 050813: KAIT optical limit
  77. GRB 050813: Swift-BAT refined analysis
  78. GRB050813: SWIFT/UVOT observation
  79. GRB 050813: Swift XRT afterglow localization
  80. GRB 050813: Possible Short Swift-BAT GRB
  81. GRB050813 (Swift 150139): P60 Observations
  82. Swift-BAT trigger 150131 is not a GRB
  83. GRB050805b: CrAO optical limit
  84. GRB050805a : Null detection report
  85. Swift-BAT trigger 149118 is very likely not a GRB
  86. Retraction of Swift Trigger 149131 (GRB 050805B)
  87. GRB 050805b: OHP optical limits
  88. GRB 050805b: TAROT optical limits
  89. GRB050805b: MASTER optical observations
  90. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  91. GRB050805a: MASTER optical candidat
  92. Swift-BAT trigger 149118 is probably not a GRB
  93. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  94. GRB 050803: Swift-BAT refined analysis
  95. GRB050803: MASTER further analys
  96. GRB 050803: early Swift XRT analysis results
  97. GRB 050803: TAROT optical limits
  98. GRB050803: MASTER optical observations
  99. GRB050803: Swift-BAT detection of a very long burst
  100. GCN GRB observation 050713A

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