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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"

18638 results found.

  1. GRB070920A: MAGIC telescope GeV observation
  2. Radio detection of GRB 071003 with the VLA
  3. GRB 070810B: further XRT analysis
  4. Konus-Wind observation of GRB 071003
  5. GRB 071003: Swift XRT position
  6. GRB 071003, Swift-BAT refined analysis
  7. GRB 071003: MARGE Observations
  8. GRB 071003 Optical observations
  9. GRB 071003: KAIT optical afterglow observations
  10. GRB 071003: Swift detection of a bright burst
  11. GRB 070714B: host galaxy spectroscopic redshift
  12. GRB 071001: Swift-XRT Team refined analysis
  13. GRB 071001, Swift-BAT refined analysis
  14. Faulkes Telescope South observations of GRB 071001
  15. GRB 071001: Swift detection of a burst
  16. VLA observation of GRB 070923
  17. Disregard the Swift-XRT Notices today
  18. GRB070925: Swift-XRT Afterglow confirmation
  19. GRB070925: Swift-XRT Position
  20. Update on Swift Status
  21. GRB 070920B: ROTSE-III Early Optical Limits
  22. Recent SGR1806-20 Activity
  23. GRB 070923, Swift-BAT refined analysis
  24. GRB 070920B: XRT observations
  25. GRB 070923: Swift detection of a short hard burst
  26. GRB 070917: Suzaku/WAM observation of the prompt emission
  27. GRB 070920B: TAROT La Silla observatory optical observations
  28. GRB 070917: Confirmation of the X-ray afterglow
  29. GRB 070920B, Swift-BAT refined analysis
  30. GRB 070911: Swift/BAT and Suzaku/WAM joint spectral analysis
  31. GRB 070920B: NOT optical observations
  32. GRB 070920B: Swift detection of a burst
  33. GRB 070920, Swift-BAT refined analysis
  34. GRB 070920: TAROT Calern observatory optical observations
  35. GRB 070920: Swift detection of a burst
  36. SGR1806-20: Swift-BAT detection of enhanced activity
  37. GRB 070917: pseudo-z= 2.40 from prompt emission spectrum
  38. Konus-Wind observation of GRB 070917
  39. Swift Status and XRT Calibration Uncertainties
  40. GRB 070917: Swift-XRT observations
  41. GRB 070917: KAIT optical limits
  42. GRB 070917: R band observations
  43. GRB 070917, Swift-BAT refined analysis
  44. GRB 070917: Swift detection of a bright burst
  45. GRB 070911: Suzaku WAM observation of the prompt emission
  46. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  47. GRB 070809: The Swift evidence for the SHB nature of this burst
  48. GRB 070913: Swift-BAT refined analysis
  49. GRB 070913: Corrected BAT position
  50. GRB 070913: TAROT La Silla observatory optical observations
  51. GRB 070913: Swift detection of a burst
  52. Swift-BAT Notices back to autonomous real-time distribution
  53. GRB 070911: Swift XRT refined analysis
  54. GRB 070911, Swift-BAT refined analysis
  55. GRB 070911: Swift detection of a burst
  56. IPN search for a GRB associated with TAROT transient on August 31
  57. Intense burst from SGR 1806-20 detected on September 7
  58. GRB 070824 - Combined SuperAGILE/IPN Localization
  59. GRB 070731: Swift/UVOT Upper Limit
  60. GRB 070805: UVOT afterglow candidate retraction
  61. GRB070810b: optical candidate
  62. GRB 070810A: ROTSE-III Refined Analysis
  63. Swift observatory off line
  64. GRB070810B: Swift/UVOT Upper Limits
  65. GRB 070810B: XRT refined analysis
  66. GRB 070810B, Swift-BAT refined analysis
  67. GRB 070809: Swift/UVOT Corrected Photometry
  68. Swift Alert 070810.8: MASTER optical observation
  69. Swift Trigger 287421: False trigger due to star tracker loss
  70. GRB 070810A: Swift-BAT refined analysis
  71. GRB 070809: Swift/UVOT Upper Limits
  72. GRB 070810B: Swift detection of a short burst
  73. VLA upper limit on the short hard burst GRB 070729
  74. No radio detection in superAGILE burst 070724B
  75. GRB 070810: Swift-XRT Team Refined Analysis
  76. GRB 070809: Swift-XRT refined analysis
  77. GRB 070810: enhanced Swift-XRT position
  78. GRB 070810: Swift/UVOT Optical Counterpart
  79. GRB 070810: ROTSE-III Detection of Optical Counterpart
  80. GRB 070810: Swift detection of a burst
  81. GRB 070809, Swift-BAT refined analysis
  82. GRB 070808: Swift/UVOT upper limits
  83. GRB 070809: ROTSE-III Optical Limits
  84. GRB 070809: Swift detection of a short burst
  85. GCN Swift XRT update position notices and enhanced position circulars
  86. GRB 070808: Swift XRT refined analysis
  87. GRB 070808, Swift-BAT refined analysis
  88. GRB070808 - SDSS Pre-Burst Observations
  89. GRB 070808: ROTSE-III Optical Limits
  90. GRB 070808: Swift detection of a burst
  91. GRB070805 XRT and UVOT afterglow candidate
  92. Swift trigger on 4U 1700-377 while star tracker loss-of-lock
  93. Swift/UVOT observations of GRB070805
  94. GRB 070805, Swift-BAT refined analysis
  95. GRB 070805: Swift XRT initial analysis.
  96. GRB 070805: Swift/UVOT initial analysis
  97. GRB 070805: Swift detection of a burst
  98. UVOT observations of SAXJ1810.8-2609
  99. Swift detection of a outburst from SAX J1810.8-2609
  100. VLA non-detection of GRB 070721B

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