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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"

19007 results found.

  1. GRB050827: RTT150 optical observations
  2. GRB 050827: Swift-BAT refined analysis
  3. GRB050827: Swift-BAT detection of a burst
  4. GRB 050826: Optical Candidate
  5. GRB050824, HETE-2 Observation
  6. GRB 050826: Swift XRT preliminary analysis results
  7. GRB 050826: BAT refined analysis
  8. GRB050826: Swift/UVOT early upper limits
  9. GRB050824: First 2 hours of power low optical decay?
  10. GRB 050826: Swift XRT position
  11. GRB050826: Swift-BAT detection of a long burst
  12. GRB050824: MASTER final analysis of the OT observations
  13. Possible GRB050825:MASTER optical observations
  14. Swift-BAT trigger 152038 is definitely not a GRB
  15. GRB050824: CORRECTION to UVOT observing times
  16. Swift-BAT trigger 152038 is probably not a GRB
  17. GRB050824: Swift/UVOT detection of fading afterglow
  18. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  19. GRB050824, I-band imaging
  20. GRB 050822: refined XRT analysis
  21. GRB 050824: XRT refined analysis and possible afterglow detection
  22. GRB 050824: BAT refined analysis of a soft weak burst
  23. GRB050824: MASTER:OT decay
  24. GRB050824: MASTER observation OT
  25. GRB050805a: MASTER optical candidat
  26. GRB 050824: ROTSE-III Optical Limits
  27. GRB050824: Swift-BAT detection of a burst
  28. GRB050822: Swift/UVOT upper limits
  29. GRB 050820A BAT observations of second, larger episode of emission
  30. GRB 050822: Swift-BAT refined analysis
  31. GRB 050820a - corrections to GCN 3846
  32. Swift/UVOT UV Photometry of GRB 050820B
  33. GRB 050822: ROTSE-III Prompt Optical Limits
  34. GRB 050822: Swift detection of a long burst
  35. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  36. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  37. GRB050820a BVRcIc field photometry
  38. GRB050820B XMM-Newton observation
  39. GRB 050820a: NIR Observations by WIRO
  40. GRB 050820B: Swift XRT position
  41. GRB050820B: Refined analysis of the Swift-BAT burst
  42. GRB050820B: BAT-Swift detection of a bright GRB
  43. Swift/UVOT photometry of GRB050820
  44. GRB050820: refined XRT analysis
  45. GRB 050820: Early RAPTOR detections
  46. GRB 050820 Swift-BAT refined analysis
  47. GRB050819: refined XRT analysis
  48. GRB 050820: Swift detection of a GRB
  49. GRB050820: Optical afterglow from P60
  50. GRB 050819 Swift-BAT refined analysis
  51. GRB050819: Swift XRT position
  52. GRB050819: Swift-BAT detection of a weak burst
  53. Swift-BAT trigger 150993 is not a GRB
  54. Swift Trigger 150823 is HETE J1900.1-2455
  55. GRB050817: Swift-BAT Detection of a burst
  56. GRB050815: Optical afterglow detection by Swift UVOT
  57. GRB050815: XRT refined analysis
  58. GRB050815: Refined analysis of the Swift-BAT burst
  59. GRB 050815: ROTSE-III Optical Limits
  60. GRB050815: Swift XRT afterglow localization
  61. GRB050815: Swift-BAT detection of a burst
  62. GRB050814: P60 Optical Afterglow Candidate
  63. GRB 050814: XRT refined analysis
  64. GRB050814: SWIFT/UVOT observation
  65. GRB050814: Refined analysis of the Swift-BAT burst
  66. GRB 050814: Swift XRT Afterglow Localization
  67. GRB 050814: Swift detection of a burst
  68. GRB050813, SDSS pre-burst observations
  69. GRB 050813: KAIT optical limit
  70. GRB 050813: Swift-BAT refined analysis
  71. GRB050813: SWIFT/UVOT observation
  72. GRB 050813: Swift XRT afterglow localization
  73. GRB 050813: Possible Short Swift-BAT GRB
  74. GRB050813 (Swift 150139): P60 Observations
  75. Swift-BAT trigger 150131 is not a GRB
  76. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  77. Detection of an intermediate burst from SGR 1806-20 on August 8
  78. GRB050805b: CrAO optical limit
  79. GRB050805a : Null detection report
  80. Swift-BAT trigger 149118 is very likely not a GRB
  81. Retraction of Swift Trigger 149131 (GRB 050805B)
  82. GRB 050805b: OHP optical limits
  83. GRB 050805b: TAROT optical limits
  84. GRB050805b: MASTER optical observations
  85. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  86. GRB050805a: MASTER optical candidat
  87. Swift-BAT trigger 149118 is probably not a GRB
  88. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  89. GRB 050803: Swift-BAT refined analysis
  90. GRB050803: MASTER further analys
  91. GRB 050803: early Swift XRT analysis results
  92. GRB 050803: TAROT optical limits
  93. GRB050803: MASTER optical observations
  94. GRB050803: Swift-BAT detection of a very long burst
  95. GCN GRB observation 050713A
  96. GRB 050802: Swift/UVOT optical and UV detections
  97. GRB050802 radio non-detection
  98. GRB 050730: OHP optical observations
  99. GRB 050802: early Swift XRT analysis results
  100. GRB 050802: Swift/UVOT observations

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