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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"

19603 results found.

  1. GRB 050908: Swift detection of a burst
  2. Swift trigger 154073 is not a GRB
  3. GRB050904: CrAO optical observations
  4. GRB 050904 BAT refined analysis of complete data set
  5. GRB 050906: MARGE Optical Limits
  6. GRB 050906: Swift-BAT refined analysis
  7. GRB 050906: Swift XRT upper limit
  8. GRB050906: P60 Observations
  9. GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
  10. GRB 050906: Bright galaxy in BAT error box
  11. GRB 050906: Swift/BAT Detection of a possible burst
  12. GRB 050904: Swift/UVOT observations
  13. GRB 050904: early Swift XRT analysis results
  14. GRB 050904: BAT refined analysis of partial data set
  15. GRB050904: P60 Observations
  16. GRB 050904: TAROT optical limits
  17. GRB050904: Swift-BAT detection of a probable burst
  18. Swift-BAT triggers 153461-153465 are not GRBs
  19. Retraction of Swift-BAT trigger #153355
  20. GRB 050824: MDM Observations
  21. GRB 050827: Swift XRT preliminary analysis results
  22. Swift Trigger #152652 is not a GRB
  23. GRB050827: Swift/UVOT upper limits
  24. GRB 050827: Optical Limit
  25. GRB 050827: XRT possible afterglow detection
  26. GRB050827: RTT150 optical observations
  27. GRB 050827: Swift-BAT refined analysis
  28. GRB050827: Swift-BAT detection of a burst
  29. GRB 050826: Optical Candidate
  30. GRB050824, HETE-2 Observation
  31. GRB 050826: Swift XRT preliminary analysis results
  32. GRB 050826: BAT refined analysis
  33. GRB050826: Swift/UVOT early upper limits
  34. GRB050824: First 2 hours of power low optical decay?
  35. GRB 050826: Swift XRT position
  36. GRB050826: Swift-BAT detection of a long burst
  37. GRB050824: MASTER final analysis of the OT observations
  38. Possible GRB050825:MASTER optical observations
  39. Swift-BAT trigger 152038 is definitely not a GRB
  40. GRB050824: CORRECTION to UVOT observing times
  41. Swift-BAT trigger 152038 is probably not a GRB
  42. GRB050824: Swift/UVOT detection of fading afterglow
  43. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  44. GRB050824, I-band imaging
  45. GRB 050822: refined XRT analysis
  46. GRB 050824: XRT refined analysis and possible afterglow detection
  47. GRB 050824: BAT refined analysis of a soft weak burst
  48. GRB050824: MASTER:OT decay
  49. GRB050824: MASTER observation OT
  50. GRB050805a: MASTER optical candidat
  51. GRB 050824: ROTSE-III Optical Limits
  52. GRB050824: Swift-BAT detection of a burst
  53. GRB050822: Swift/UVOT upper limits
  54. GRB 050820A BAT observations of second, larger episode of emission
  55. GRB 050822: Swift-BAT refined analysis
  56. GRB 050820a - corrections to GCN 3846
  57. Swift/UVOT UV Photometry of GRB 050820B
  58. GRB 050822: ROTSE-III Prompt Optical Limits
  59. GRB 050822: Swift detection of a long burst
  60. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  61. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  62. GRB050820a BVRcIc field photometry
  63. GRB050820B XMM-Newton observation
  64. GRB 050820a: NIR Observations by WIRO
  65. GRB 050820B: Swift XRT position
  66. GRB050820B: Refined analysis of the Swift-BAT burst
  67. GRB050820B: BAT-Swift detection of a bright GRB
  68. Swift/UVOT photometry of GRB050820
  69. GRB050820: refined XRT analysis
  70. GRB 050820: Early RAPTOR detections
  71. GRB 050820 Swift-BAT refined analysis
  72. GRB050819: refined XRT analysis
  73. GRB 050820: Swift detection of a GRB
  74. GRB050820: Optical afterglow from P60
  75. GRB 050819 Swift-BAT refined analysis
  76. GRB050819: Swift XRT position
  77. GRB050819: Swift-BAT detection of a weak burst
  78. Swift-BAT trigger 150993 is not a GRB
  79. Swift Trigger 150823 is HETE J1900.1-2455
  80. GRB050817: Swift-BAT Detection of a burst
  81. GRB050815: Optical afterglow detection by Swift UVOT
  82. GRB050815: XRT refined analysis
  83. GRB050815: Refined analysis of the Swift-BAT burst
  84. GRB 050815: ROTSE-III Optical Limits
  85. GRB050815: Swift XRT afterglow localization
  86. GRB050815: Swift-BAT detection of a burst
  87. GRB050814: P60 Optical Afterglow Candidate
  88. GRB 050814: XRT refined analysis
  89. GRB050814: SWIFT/UVOT observation
  90. GRB050814: Refined analysis of the Swift-BAT burst
  91. GRB 050814: Swift XRT Afterglow Localization
  92. GRB 050814: Swift detection of a burst
  93. GRB050813, SDSS pre-burst observations
  94. GRB 050813: KAIT optical limit
  95. GRB 050813: Swift-BAT refined analysis
  96. GRB050813: SWIFT/UVOT observation
  97. GRB 050813: Swift XRT afterglow localization
  98. GRB 050813: Possible Short Swift-BAT GRB
  99. GRB050813 (Swift 150139): P60 Observations
  100. Swift-BAT trigger 150131 is not a GRB

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