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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"

18672 results found.

  1. GRB 050826: BAT refined analysis
  2. GRB050826: Swift/UVOT early upper limits
  3. GRB050824: First 2 hours of power low optical decay?
  4. GRB 050826: Swift XRT position
  5. GRB050826: Swift-BAT detection of a long burst
  6. GRB050824: MASTER final analysis of the OT observations
  7. Possible GRB050825:MASTER optical observations
  8. Swift-BAT trigger 152038 is definitely not a GRB
  9. GRB050824: CORRECTION to UVOT observing times
  10. Swift-BAT trigger 152038 is probably not a GRB
  11. GRB050824: Swift/UVOT detection of fading afterglow
  12. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  13. GRB050824, I-band imaging
  14. GRB 050822: refined XRT analysis
  15. GRB 050824: XRT refined analysis and possible afterglow detection
  16. GRB 050824: BAT refined analysis of a soft weak burst
  17. GRB050824: MASTER:OT decay
  18. GRB050824: MASTER observation OT
  19. GRB050805a: MASTER optical candidat
  20. GRB 050824: ROTSE-III Optical Limits
  21. GRB050824: Swift-BAT detection of a burst
  22. GRB050822: Swift/UVOT upper limits
  23. GRB 050820A BAT observations of second, larger episode of emission
  24. GRB 050822: Swift-BAT refined analysis
  25. GRB 050820a - corrections to GCN 3846
  26. Swift/UVOT UV Photometry of GRB 050820B
  27. GRB 050822: ROTSE-III Prompt Optical Limits
  28. GRB 050822: Swift detection of a long burst
  29. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  30. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  31. GRB050820a BVRcIc field photometry
  32. GRB050820B XMM-Newton observation
  33. GRB 050820a: NIR Observations by WIRO
  34. GRB 050820B: Swift XRT position
  35. GRB050820B: Refined analysis of the Swift-BAT burst
  36. GRB050820B: BAT-Swift detection of a bright GRB
  37. Swift/UVOT photometry of GRB050820
  38. GRB050820: refined XRT analysis
  39. GRB 050820: Early RAPTOR detections
  40. GRB 050820 Swift-BAT refined analysis
  41. GRB050819: refined XRT analysis
  42. GRB 050820: Swift detection of a GRB
  43. GRB050820: Optical afterglow from P60
  44. GRB 050819 Swift-BAT refined analysis
  45. GRB050819: Swift XRT position
  46. GRB050819: Swift-BAT detection of a weak burst
  47. Swift-BAT trigger 150993 is not a GRB
  48. Swift Trigger 150823 is HETE J1900.1-2455
  49. GRB050817: Swift-BAT Detection of a burst
  50. GRB050815: Optical afterglow detection by Swift UVOT
  51. GRB050815: XRT refined analysis
  52. GRB050815: Refined analysis of the Swift-BAT burst
  53. GRB 050815: ROTSE-III Optical Limits
  54. GRB050815: Swift XRT afterglow localization
  55. GRB050815: Swift-BAT detection of a burst
  56. GRB050814: P60 Optical Afterglow Candidate
  57. GRB 050814: XRT refined analysis
  58. GRB050814: SWIFT/UVOT observation
  59. GRB050814: Refined analysis of the Swift-BAT burst
  60. GRB 050814: Swift XRT Afterglow Localization
  61. GRB 050814: Swift detection of a burst
  62. GRB050813, SDSS pre-burst observations
  63. GRB 050813: KAIT optical limit
  64. GRB 050813: Swift-BAT refined analysis
  65. GRB050813: SWIFT/UVOT observation
  66. GRB 050813: Swift XRT afterglow localization
  67. GRB 050813: Possible Short Swift-BAT GRB
  68. GRB050813 (Swift 150139): P60 Observations
  69. Swift-BAT trigger 150131 is not a GRB
  70. GRB050805b: CrAO optical limit
  71. GRB050805a : Null detection report
  72. Swift-BAT trigger 149118 is very likely not a GRB
  73. Retraction of Swift Trigger 149131 (GRB 050805B)
  74. GRB 050805b: OHP optical limits
  75. GRB 050805b: TAROT optical limits
  76. GRB050805b: MASTER optical observations
  77. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  78. GRB050805a: MASTER optical candidat
  79. Swift-BAT trigger 149118 is probably not a GRB
  80. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  81. GRB 050803: Swift-BAT refined analysis
  82. GRB050803: MASTER further analys
  83. GRB 050803: early Swift XRT analysis results
  84. GRB 050803: TAROT optical limits
  85. GRB050803: MASTER optical observations
  86. GRB050803: Swift-BAT detection of a very long burst
  87. GCN GRB observation 050713A
  88. GRB 050802: Swift/UVOT optical and UV detections
  89. GRB050802 radio non-detection
  90. GRB 050730: OHP optical observations
  91. GRB 050802: early Swift XRT analysis results
  92. GRB 050802: Swift/UVOT observations
  93. GRB 050802: Swift-BAT refined analysis
  94. GRB 050802: XRT position
  95. GRB 050802: Swift Gamma-ray Burst
  96. GRB050801: Swift/UVOT Optical and UV detections
  97. GCN 050801: early Swift XRT analysis results
  98. GRB 050801: Swift-BAT refined analysis
  99. GRB 050801, afterglow observations
  100. GRB 050730, corrected photometry and break?

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