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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"

19938 results found.

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

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