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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"

27784 results found.

  1. Konus-Wind detection of GRB 221022C
  2. GRB 221029A: Fermi GBM Final Localization
  3. GRB 221028A: Swift-XRT refined Analysis
  4. GRB 221028A: 1.3m DFOT Optical upper limit
  5. GRB 221028A, Swift-BAT refined analysis
  6. GRB 221027B: Swift-BAT refined analysis
  7. GRB 221029A: Swift/BAT-GUANO detection outside the coded FOV
  8. GRB 221029A: Detection by GRBAlpha
  9. Trigger 1132968: Swift trigger is the Crab
  10. GRB 221028A: HCT optical upper limit
  11. GRB 221028A: AGILE detection
  12. GRB 221027A: AGILE detection
  13. GRB 221028A: MITSuME Okayama optical upper limits
  14. GRB 221028B: MAXI/GSC detection
  15. Swift GRB 221028A: Global MASTER-Net observations report
  16. GRB 221028A: BOOTES-4/MET optical upper limit
  17. GRB 221028A: GIT optical upper limit
  18. GRB 221027B: Swift/UVOT Upper Limits
  19. GRB 221028A: Swift detection of a burst
  20. GRB 221027B: FRAM-ORM and Ondrejov SBT optical limits
  21. Konus-Wind detection of GRB 221017A
  22. Swift GRB 221027B: Global MASTER-Net observations report
  23. GRB 221027B: Swift-XRT refined Analysis
  24. GRB 221027B: BOOTES-1 optical upper limit
  25. GRB 221027B: Enhanced Swift-XRT position
  26. GRB 221027B: Swift detection of a burst
  27. GRB 221027A: Fermi GBM detection
  28. IPN triangulation of GRB 221025A (short)
  29. Konus-Wind detection of GRB 221022B
  30. GRB 221024A: Mondy optical observations
  31. GRB 221027A: Fermi-LAT detection
  32. GRB 221027A: Fermi GBM Final Real-time Localization
  33. GRB 221024A: GRANDMA observations
  34. IPN triangulation of GRB 221022C (short)
  35. GRB 221023A: AGILE/GRID analysis
  36. SGR 1935+2154: AstroSat CZTI Detections
  37. GRB 221024A: Swift-BAT refined analysis
  38. GRB 221025A: AstroSat CZTI detection
  39. GRB 221009A: SARA-RM 1m Optical Afterglow Detection
  40. GRB 221009A: spectroscopic confirmation of SN in LBT spectra
  41. Konus-Wind detection of GRB 221023A
  42. GRB 221024A: Swift/UVOT UV upper limits
  43. GRB 221022A: Swift-XRT observations
  44. GRB 221024A: Swift-XRT refined Analysis
  45. GRB 221022B: Detection by GRBAlpha
  46. GRB 221025A: Fermi-LAT detection
  47. IPN triangulation of GRB 221022B (long)
  48. GRB 221024A: GIT confirmation of the optical afterglow
  49. GRB 221024A: Enhanced Swift-XRT position
  50. GRB 221024A: D50 candidate afterglow
  51. GRB 221022B: AstroSat CZTI detection
  52. GRB 221022A: Fermi GBM detection
  53. GRB 221022A: Swift ToO observations
  54. GRB 221023A: Fermi-LAT detection
  55. GRB 221022B: Fermi GBM detection
  56. GRB 221021A: Fermi GBM observation
  57. GRB 221009A: Determination of the black holes mass and spin
  58. GRB 221024A: Swift detection of a burst
  59. GRB 221023A: Fermi GBM Final Localization
  60. GRB 221023A: AGILE detection of a burst
  61. GRB 221022A: Swift/BAT-GUANO detection
  62. GRB 221022B: Swift/BAT-GUANO detection outside the coded FOV
  63. GRB 221022B: AGILE detection
  64. GRB 221022B: Fermi GBM Final Real-time Localization
  65. GRB 221009A: optical observations, SN photometric evidence
  66. GRB 221021A: Swift/BAT-GUANO detection outside the coded FOV
  67. GRB 221022A: Fermi GBM Final Real-time Localization
  68. GRB 221020A: Detection by GRBAlpha
  69. SGR 1935+21542: VZLUSAT-2 and GRBAlpha joint detection
  70. GRB 221017A: CALET Gamma-Ray Burst Monitor detection
  71. GRB 221021A: Fermi GBM Final Real-time Localization
  72. GRB 221009A: 1.3m DFOT Optical Observations
  73. GRB 221017A: Swift-XRT observations
  74. GRB 221020A: Fermi GBM Final Real-time Localization
  75. Improved IPN localization for GRB 221009A (BepiColombo-MGNS light curve)
  76. GRB 221009A: TNG NIR detection
  77. GRB 221009A: BOAO NIR detections
  78. GRB 221009A X-ray light-curve and the indication of TeV light-curve
  79. AGILE detection of a burst from SGR J1935+2154 reported by VZLUSAT-2
  80. GRB 221009A: Spectroscopic detection of emerging SN features
  81. GRB 221013B: Swift/BAT-GUANO detection
  82. SGR 1935+2154: Bursting activity detected by VZLUSAT-2
  83. AGILE detection of the 2022 October 17 burst from SGR J1935+2154 reported by Konus-Wind
  84. GRB 221009A: GRANDMA observations
  85. SGR 1935+2154: Detection by GRBAlpha
  86. The probability of observing GRB 221009A at z = 0.151
  87. Konus-Wind detection of a burst from SGR 1935+2154 on 2022 October 17
  88. GRB 221017A: Swift ToO observations
  89. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  90. GRB 221009A: Second epoch of NuSTAR data
  91. IPN triangulation of GRB 221017A (long)
  92. GRB 221016A: Swift-BAT refined analysis
  93. GRB 221016A: Swift/UVOT Detection
  94. GRB 221016A: Swift-XRT refined Analysis
  95. Konus-Wind detection of GRB 221016A
  96. GRB 221016A: Fermi GBM observation
  97. GRB 220926B: Detection by GRBAlpha
  98. GRB 221009A: A type I BdHN of exceptional energetics
  99. GRB 221017A: MAXI/GSC detection
  100. GRB 221016A: Enhanced Swift-XRT position

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