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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"
  1. GRB 071010: Swift detection of a burst
  2. GRB 071006 Swift-BAT detection of a burst
  3. GRB071008: IAC80 observation
  4. GRB 071008: Swift detection of a burst
  5. GRB 071003: XRT refined analysis
  6. GRB070920A: MAGIC telescope GeV observation
  7. Radio detection of GRB 071003 with the VLA
  8. GRB 070810B: further XRT analysis
  9. GRB 071003: VLT spectroscopy
  10. GRB 071003: Keck spectroscopy
  11. Konus-Wind observation of GRB 071003
  12. GRB071003: Faulkes Telescope North observations
  13. GRB 071003: Possible rebrightening
  14. GRB 071003 : Lulin R-band observations
  15. GRB 071003: Swift XRT position
  16. GRB 071003: OA power-law decay indices from KAIT
  17. GRB 071003: Keck HIRES spectroscopy
  18. GRB 071003, Swift-BAT refined analysis
  19. GRB 071003: MARGE Observations
  20. GRB 071003 Optical observations
  21. GRB 071003: P60 Confirmation of Optical Afterglow
  22. GRB 071003: KAIT optical afterglow observations
  23. GRB 071003: Swift detection of a bright burst
  24. GRB 070714B: host galaxy spectroscopic redshift
  25. GRB 071001: Swift-XRT Team refined analysis
  26. GRB 071001, Swift-BAT refined analysis
  27. Faulkes Telescope South observations of GRB 071001
  28. GRB 071001: Swift detection of a burst
  29. VLA observation of GRB 070923
  30. Disregard the Swift-XRT Notices today
  31. GRB 070911, SMARTS optical/IR afterglow observations
  32. GRB070925: Swift-XRT Afterglow confirmation
  33. GRB 070925: Gemini South Imaging
  34. GRB070925: Swift-XRT Position
  35. Update on Swift Status
  36. GRB 070920B: ROTSE-III Early Optical Limits
  37. GRB 070925: a long GRB detected by INTEGRAL
  38. Recent SGR1806-20 Activity
  39. GRB 070923, Swift-BAT refined analysis
  40. GRB 070920B: XRT observations
  41. GRB 070923: Galaxies within BAT localization
  42. GRB 070923: Swift detection of a short hard burst
  43. GRB 070917: Suzaku/WAM observation of the prompt emission
  44. GRB 070920B: TAROT La Silla observatory optical observations
  45. INTEGRAL ToO observations of SGR1806-20
  46. GRB 070920b, SMARTS optical observation
  47. GRB 070917: Confirmation of the X-ray afterglow
  48. GRB 070920b: LCO optical observations
  49. GRB 070920B, Swift-BAT refined analysis
  50. GRB 070911: Swift/BAT and Suzaku/WAM joint spectral analysis
  51. GRB 070920B: NOT optical observations
  52. GRB 070920B: Swift detection of a burst
  53. GRB 070920, Swift-BAT refined analysis
  54. GRB 070920: TAROT Calern observatory optical observations
  55. GRB 070920: Swift detection of a burst
  56. SGR1806-20: Swift-BAT detection of enhanced activity
  57. GRB070917: Confirmation of optical afterglow
  58. GRB920925C: search for host galaxy
  59. GRB070917: optical observations
  60. GRB 070917: P60 Observations
  61. GRB 070917: pseudo-z= 2.40 from prompt emission spectrum
  62. Konus-Wind observation of GRB 070917
  63. Swift Status and XRT Calibration Uncertainties
  64. GRB 070917: Swift-XRT observations
  65. GRB 070917: KAIT optical limits
  66. GRB 070917: MITSuME Akeno Ic upper limit
  67. GRB 070917: R band observations
  68. GRB 070917, Swift-BAT refined analysis
  69. GRB 070917: Swift detection of a bright burst
  70. GRB 070911: Suzaku WAM observation of the prompt emission
  71. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  72. GRB 070809: The Swift evidence for the SHB nature of this burst
  73. GRB 070913: Afterglow candidate detected by TAROT La Silla observatory
  74. GRB 070913: Swift-BAT refined analysis
  75. GRB 070913: Corrected BAT position
  76. GRB 070913: SMARTS optical/IR observations
  77. GRB 070913: TAROT La Silla observatory optical observations
  78. GRB 070913: Swift detection of a burst
  79. Swift-BAT Notices back to autonomous real-time distribution
  80. GRB 070911: PAIRITEL IR Observations
  81. GRB 070911: Swift XRT refined analysis
  82. GRB 070911, Swift-BAT refined analysis
  83. GRB 070911: Swift detection of a burst
  84. IPN search for a GRB associated with TAROT transient on August 31
  85. Intense burst from SGR 1806-20 detected on September 7
  86. GRB 070809: Confirmation of optical transient
  87. Observations of possible TAROT GRB transient near IC 4779
  88. Candidate Orphan GRB Optical Transient in IC 4779
  89. GRB 070810b: Image Subtraction of Multiple Keck Observations
  90. Las Campanas observations of possible TAROT GRB transient near IC
  91. Orphan GRB candidate in IC 4779 at TAROT La Silla observatory
  92. Konus-Wind observation of GRB 070824
  93. GRB 070824 - Combined SuperAGILE/IPN Localization
  94. Konus-Wind observation of very bright GRB 070821
  95. GRB 070731: Swift/UVOT Upper Limit
  96. IPN Localization of GRB 070821 (long, very bright)
  97. GRB 070805: UVOT afterglow candidate retraction
  98. GRB070810b: optical candidate
  99. GRB 070810A: ROTSE-III Refined Analysis
  100. Swift observatory off line

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