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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').

18034 results found.

  1. GRB 071003, Swift-BAT refined analysis
  2. GRB 071003: MARGE Observations
  3. GRB 071003 Optical observations
  4. GRB 071003: KAIT optical afterglow observations
  5. GRB 071003: Swift detection of a bright burst
  6. GRB 070714B: host galaxy spectroscopic redshift
  7. GRB 071001: Swift-XRT Team refined analysis
  8. GRB 071001, Swift-BAT refined analysis
  9. Faulkes Telescope South observations of GRB 071001
  10. GRB 071001: Swift detection of a burst
  11. VLA observation of GRB 070923
  12. Disregard the Swift-XRT Notices today
  13. GRB070925: Swift-XRT Afterglow confirmation
  14. GRB070925: Swift-XRT Position
  15. Update on Swift Status
  16. GRB 070920B: ROTSE-III Early Optical Limits
  17. Recent SGR1806-20 Activity
  18. GRB 070923, Swift-BAT refined analysis
  19. GRB 070920B: XRT observations
  20. GRB 070923: Swift detection of a short hard burst
  21. GRB 070917: Suzaku/WAM observation of the prompt emission
  22. GRB 070920B: TAROT La Silla observatory optical observations
  23. GRB 070917: Confirmation of the X-ray afterglow
  24. GRB 070920B, Swift-BAT refined analysis
  25. GRB 070911: Swift/BAT and Suzaku/WAM joint spectral analysis
  26. GRB 070920B: NOT optical observations
  27. GRB 070920B: Swift detection of a burst
  28. GRB 070920, Swift-BAT refined analysis
  29. GRB 070920: TAROT Calern observatory optical observations
  30. GRB 070920: Swift detection of a burst
  31. SGR1806-20: Swift-BAT detection of enhanced activity
  32. GRB 070917: pseudo-z= 2.40 from prompt emission spectrum
  33. Konus-Wind observation of GRB 070917
  34. Swift Status and XRT Calibration Uncertainties
  35. GRB 070917: Swift-XRT observations
  36. GRB 070917: KAIT optical limits
  37. GRB 070917: R band observations
  38. GRB 070917, Swift-BAT refined analysis
  39. GRB 070917: Swift detection of a bright burst
  40. GRB 070911: Suzaku WAM observation of the prompt emission
  41. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  42. GRB 070809: The Swift evidence for the SHB nature of this burst
  43. GRB 070913: Swift-BAT refined analysis
  44. GRB 070913: Corrected BAT position
  45. GRB 070913: TAROT La Silla observatory optical observations
  46. GRB 070913: Swift detection of a burst
  47. Swift-BAT Notices back to autonomous real-time distribution
  48. GRB 070911: Swift XRT refined analysis
  49. GRB 070911, Swift-BAT refined analysis
  50. GRB 070911: Swift detection of a burst
  51. IPN search for a GRB associated with TAROT transient on August 31
  52. Intense burst from SGR 1806-20 detected on September 7
  53. GRB 070824 - Combined SuperAGILE/IPN Localization
  54. GRB 070731: Swift/UVOT Upper Limit
  55. GRB 070805: UVOT afterglow candidate retraction
  56. GRB070810b: optical candidate
  57. GRB 070810A: ROTSE-III Refined Analysis
  58. Swift observatory off line
  59. GRB070810B: Swift/UVOT Upper Limits
  60. GRB 070810B: XRT refined analysis
  61. GRB 070810B, Swift-BAT refined analysis
  62. GRB 070809: Swift/UVOT Corrected Photometry
  63. Swift Alert 070810.8: MASTER optical observation
  64. Swift Trigger 287421: False trigger due to star tracker loss
  65. GRB 070810A: Swift-BAT refined analysis
  66. GRB 070809: Swift/UVOT Upper Limits
  67. GRB 070810B: Swift detection of a short burst
  68. VLA upper limit on the short hard burst GRB 070729
  69. No radio detection in superAGILE burst 070724B
  70. GRB 070810: Swift-XRT Team Refined Analysis
  71. GRB 070809: Swift-XRT refined analysis
  72. GRB 070810: enhanced Swift-XRT position
  73. GRB 070810: Swift/UVOT Optical Counterpart
  74. GRB 070810: ROTSE-III Detection of Optical Counterpart
  75. GRB 070810: Swift detection of a burst
  76. GRB 070809, Swift-BAT refined analysis
  77. GRB 070808: Swift/UVOT upper limits
  78. GRB 070809: ROTSE-III Optical Limits
  79. GRB 070809: Swift detection of a short burst
  80. GCN Swift XRT update position notices and enhanced position circulars
  81. GRB 070808: Swift XRT refined analysis
  82. GRB 070808, Swift-BAT refined analysis
  83. GRB070808 - SDSS Pre-Burst Observations
  84. GRB 070808: ROTSE-III Optical Limits
  85. GRB 070808: Swift detection of a burst
  86. GRB070805 XRT and UVOT afterglow candidate
  87. Swift trigger on 4U 1700-377 while star tracker loss-of-lock
  88. Swift/UVOT observations of GRB070805
  89. GRB 070805, Swift-BAT refined analysis
  90. GRB 070805: Swift XRT initial analysis.
  91. GRB 070805: Swift/UVOT initial analysis
  92. GRB 070805: Swift detection of a burst
  93. UVOT observations of SAXJ1810.8-2609
  94. Swift detection of a outburst from SAX J1810.8-2609
  95. VLA non-detection of GRB 070721B
  96. GRB 070802: REM optical observations
  97. GRB 070724B: Swift-XRT afterglow confirmation
  98. GRB 070802: Swift-XRT refined analysis
  99. GRB070802: Swift/UVOT upper limits
  100. GRB 070802, Swift-BAT refined analysis

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