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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"

2907 results found.

  1. Short GRB 110106A: MASTER OT observations
  2. GRB 110106B: Gemini-North / WHT detection of a fading afterglow
  3. GRB 110106B: WHT candidate afterglow
  4. GRB 101225A: Swift/UVOT Detection
  5. GRB101224A: MITSuME Okayama optical upper limits
  6. IPN triangulation of bright GRB 101123A
  7. GGRB 101023A: GROND detection of the optical-NIR afterglow
  8. GRB 101017A: Swift detection of a burst with optical counterpart
  9. Konus-Wind observation of GRB 101014A
  10. GRB 101014A: Fermi GBM detection
  11. MAXI J1659-152: Swift-BAT refined analysis (triggers 434928 and 434931)
  12. GRB 100915A: TAROT Calern observatory optical observations
  13. GRB 100901A: TLS observations, SDSS calibration, decay slope
  14. Konus-Wind observation of GRB 100829A
  15. GRB 100901A: optical observation at Mt.Terskol
  16. GRB 100901A: optical observation at Mt.Terskol
  17. GRB 100901A: MASTER Optical Early Limits
  18. GRB 100823A: optical observations
  19. GRB 100807A: P200 Infrared Observations
  20. GRB 100807A: P60 Optical Afterglow Discovery
  21. GRB 100805A: Swift detection of a burst with an optical counterpart
  22. GRB 100802A: NOT optical observation
  23. GRB 100802A: ROTSE-III Optical Limits
  24. GRB 100802A: Possible Swift/UVOT Detection of Optical Afterglow
  25. GRB 100727A: Swift/UVOT Upper Limits
  26. GRB 100718A: MASTER-Net optical prompt and alert observations
  27. GRB 100702A: Swift detection of a short burst
  28. Swift-BAT trigger 426048 is not a burst
  29. GRB 100513A: CrAO optical observations
  30. GRB 100526A: NOT optical upper limit
  31. GRB 100510A: MAXI/GSC detection
  32. GRB 100418A: Terskol optical observations
  33. GRB 100425A: Swift detection of a burst
  34. Swift Trigger 420256: ROTSE-III Optical Limits
  35. GRB 100420A: Swift detection of a burst
  36. GRB 100316C: BOOTES-3 observations
  37. GRB 100316D: Swift detection of a burst
  38. GRB 100316A: Enhanced Swift-XRT position
  39. GRB 100316B: Swift detection of a burst with optical counterpart
  40. GRB 100316A: Swift-XRT detection
  41. GRB100219A Akeno and Okayama MITSuME Optical Observation
  42. GRB 100203A Detected in Ground Analysis of BAT Data
  43. GRB 100122A: Fermi GBM detection
  44. Konus-Wind observation of GRB 091208A
  45. GRB 091208B, RIMOTS optical upper limits
  46. Short X-ray Transient Detection by MAXI/GSC
  47. GRB 091130: MASTER observations
  48. GRB 091120: MAXI GSC detection
  49. GRB 091117A: Swift/UVOT followup observations
  50. GRB 091024: optical observations
  51. GRB 091018: GROND observations
  52. GRB 091010 optical upper limits
  53. GRB090829: Fermi GBM Detection
  54. GRB 090817: aphotometry of USNO-B1.0 341-0096763
  55. GRB 090813: P60 Optical Afterglow Confirmation
  56. Swift trigger 358760 is probably a noise event
  57. GRB 090728: Swift detection of a burst
  58. IPN Triangulation of bright GRB 090720B
  59. GRB 090715B: VLA radio detection
  60. GRB 090717: Fermi GBM detection
  61. GRB090709A : WSRT Radio observation
  62. GRB 090704: Fermi GBM observation
  63. GRB 090704: a long GRB found in INTEGRAL off-line analysis
  64. GRB 090706: Fermi GBM detection
  65. GRB 090621B: GRT Optical Observation
  66. GRB 090618 : WSRT radio detection
  67. VLA radio detection of GRB 090618
  68. GRB 090424: WSRT Radio Observations
  69. GRB 090607: Swift detection of a burst
  70. GRB 090529C: Fermi GBM detection
  71. GRB 090529: MITSuME optical observation
  72. GRB 090531B: ROTSE-III Optical Limits
  73. GRB 090531: GROND upper limits
  74. GRB 090531: P60 Observations
  75. GRB 090531: Swift detection of a burst
  76. GRB 090530: GRAS002 optical observations
  77. GRB 090515: KAIT optical upper limits
  78. GRB 090510B: Fermi GBM detection
  79. GRB 090426: optical observations
  80. GRB 090426: R-band limit
  81. GRB 090426: Swift detection of a burst with an optical counterpart
  82. GRB 090424: Liverpool Telescope observations
  83. GRB 090423 limiting magnitudes
  84. GRB 090418B: Detection of a bright burst from Swift-BAT slew data
  85. GRB 090417B: Swift-XRT refined analysis
  86. GRB 090411B: Suzaku WAM observation of the prompt emission
  87. GRB 090411B: Fermi GBM detection
  88. Swift-BAT trigger 348781: almost certainly not a burst
  89. GRB 090403: Fermi GBM detection
  90. GRB090401B, RIMOTS optical upper limits
  91. GRB 090401B: Swift detection of a burst
  92. GRB 090324: Suzaku WAM observation of the prompt emission
  93. GRB 090323: Swift-XRT refined analysis
  94. GRB 090313 - PAIRITEL NIR detections
  95. IPN localization of short GRB 090305C
  96. Konus-Wind observation of bright short GRB 090227B
  97. IPN localization of short bright GRB 090227B
  98. VLA radio upper limit on GRB 090205
  99. Konus-Wind observation of GRB 090201
  100. GRB 090201: Swift-XRT refined analysis

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