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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"

18402 results found.

  1. Swift trigger 154073 is not a GRB
  2. GRB050904: CrAO optical observations
  3. GRB 050904 BAT refined analysis of complete data set
  4. GRB 050906: MARGE Optical Limits
  5. GRB 050906: Swift-BAT refined analysis
  6. GRB 050906: Swift XRT upper limit
  7. GRB050906: P60 Observations
  8. GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
  9. GRB 050906: Bright galaxy in BAT error box
  10. GRB 050906: Swift/BAT Detection of a possible burst
  11. GRB 050904: Swift/UVOT observations
  12. GRB 050904: early Swift XRT analysis results
  13. GRB 050904: BAT refined analysis of partial data set
  14. GRB050904: P60 Observations
  15. GRB 050904: TAROT optical limits
  16. GRB050904: Swift-BAT detection of a probable burst
  17. Swift-BAT triggers 153461-153465 are not GRBs
  18. Retraction of Swift-BAT trigger #153355
  19. GRB 050824: MDM Observations
  20. GRB 050827: Swift XRT preliminary analysis results
  21. Swift Trigger #152652 is not a GRB
  22. GRB050827: Swift/UVOT upper limits
  23. GRB 050827: Optical Limit
  24. GRB 050827: XRT possible afterglow detection
  25. GRB050827: RTT150 optical observations
  26. GRB 050827: Swift-BAT refined analysis
  27. GRB050827: Swift-BAT detection of a burst
  28. GRB 050826: Optical Candidate
  29. GRB050824, HETE-2 Observation
  30. GRB 050826: Swift XRT preliminary analysis results
  31. GRB 050826: BAT refined analysis
  32. GRB050826: Swift/UVOT early upper limits
  33. GRB050824: First 2 hours of power low optical decay?
  34. GRB 050826: Swift XRT position
  35. GRB050826: Swift-BAT detection of a long burst
  36. GRB050824: MASTER final analysis of the OT observations
  37. Possible GRB050825:MASTER optical observations
  38. Swift-BAT trigger 152038 is definitely not a GRB
  39. GRB050824: CORRECTION to UVOT observing times
  40. Swift-BAT trigger 152038 is probably not a GRB
  41. GRB050824: Swift/UVOT detection of fading afterglow
  42. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  43. GRB050824, I-band imaging
  44. GRB 050822: refined XRT analysis
  45. GRB 050824: XRT refined analysis and possible afterglow detection
  46. GRB 050824: BAT refined analysis of a soft weak burst
  47. GRB050824: MASTER:OT decay
  48. GRB050824: MASTER observation OT
  49. GRB050805a: MASTER optical candidat
  50. GRB 050824: ROTSE-III Optical Limits
  51. GRB050824: Swift-BAT detection of a burst
  52. GRB050822: Swift/UVOT upper limits
  53. GRB 050820A BAT observations of second, larger episode of emission
  54. GRB 050822: Swift-BAT refined analysis
  55. GRB 050820a - corrections to GCN 3846
  56. Swift/UVOT UV Photometry of GRB 050820B
  57. GRB 050822: ROTSE-III Prompt Optical Limits
  58. GRB 050822: Swift detection of a long burst
  59. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  60. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  61. GRB050820a BVRcIc field photometry
  62. GRB050820B XMM-Newton observation
  63. GRB 050820a: NIR Observations by WIRO
  64. GRB 050820B: Swift XRT position
  65. GRB050820B: Refined analysis of the Swift-BAT burst
  66. GRB050820B: BAT-Swift detection of a bright GRB
  67. Swift/UVOT photometry of GRB050820
  68. GRB050820: refined XRT analysis
  69. GRB 050820: Early RAPTOR detections
  70. GRB 050820 Swift-BAT refined analysis
  71. GRB050819: refined XRT analysis
  72. GRB 050820: Swift detection of a GRB
  73. GRB050820: Optical afterglow from P60
  74. GRB 050819 Swift-BAT refined analysis
  75. GRB050819: Swift XRT position
  76. GRB050819: Swift-BAT detection of a weak burst
  77. Swift-BAT trigger 150993 is not a GRB
  78. Swift Trigger 150823 is HETE J1900.1-2455
  79. GRB050817: Swift-BAT Detection of a burst
  80. GRB050815: Optical afterglow detection by Swift UVOT
  81. GRB050815: XRT refined analysis
  82. GRB050815: Refined analysis of the Swift-BAT burst
  83. GRB 050815: ROTSE-III Optical Limits
  84. GRB050815: Swift XRT afterglow localization
  85. GRB050815: Swift-BAT detection of a burst
  86. GRB050814: P60 Optical Afterglow Candidate
  87. GRB 050814: XRT refined analysis
  88. GRB050814: SWIFT/UVOT observation
  89. GRB050814: Refined analysis of the Swift-BAT burst
  90. GRB 050814: Swift XRT Afterglow Localization
  91. GRB 050814: Swift detection of a burst
  92. GRB050813, SDSS pre-burst observations
  93. GRB 050813: KAIT optical limit
  94. GRB 050813: Swift-BAT refined analysis
  95. GRB050813: SWIFT/UVOT observation
  96. GRB 050813: Swift XRT afterglow localization
  97. GRB 050813: Possible Short Swift-BAT GRB
  98. GRB050813 (Swift 150139): P60 Observations
  99. Swift-BAT trigger 150131 is not a GRB
  100. GRB050805b: CrAO optical limit

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