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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"

14835 results found.

  1. GRB 240124B: AstroSat CZTI detection
  2. GRB 240123C: AstroSat CZTI detection
  3. GRB 240125B: Fermi GBM Final Localization
  4. GRB240122A: PRIME near infrared detection
  5. GRB 240123A: Glowbug gamma-ray detection
  6. GRB 240125A (short): Glowbug gamma-ray detection
  7. GRB 240123B: Swift/BAT-GUANO detection of a long burst
  8. GRB 240123A: GRBAlpha detection
  9. GRB 240122B: CALET Gamma-Ray Burst Monitor detection
  10. GRB 240123A : MITSuME Akeno optical afterglow candidate detection
  11. GRB 240122A: Swift/UVOT Upper Limits
  12. GRB 240122A: BOOTES-2/TELMA optical upper limit and 1.5m OSN detection
  13. Fermi GBM Sub-Threshold Detection of GRB 240123A
  14. GRB 240123B: Fermi GBM Final Real-time Localization
  15. GRB 240122B: Glowbug gamma-ray detection
  16. IceCube-240123A - IceCube observation of a high-energy neutrino candidate track-like event
  17. Konus-Wind detection of GRB 240112A
  18. GRB 240123A: Swift detection of a burst with a possible optical counterpart
  19. GRB 240122A: Swift-XRT afterglow detection
  20. GRB 240122A: VLT/X-shooter redshift confirmation
  21. GRB 240122A: LT non-detection of GOTO candidate counterpart confirms fading
  22. Konus-Wind detection of GRB 240119A (short/hard)
  23. GRB 240122A: MAXI/GSC detection
  24. IPN triangulation of GRB 240119A (short)
  25. GRB 240119A: GECAM detection of a short burst
  26. GRB 240118C: GECAM-B detection of a long burst
  27. GRB 240119A: AstroSat CZTI detection of a short burst
  28. GRB 240118A: Swift-XRT afterglow detection
  29. IceCube-240105A: Detection of NIR flare of PKS 0446+11 with WINTER
  30. GRB 240119A: Fermi GBM Final Localization
  31. GRB 240117A: CALET Gamma-Ray Burst Monitor detection
  32. GRB 240118C: Swift/BAT-GUANO detection of a burst
  33. GRB 240118A: GRBAlpha detection
  34. GRB 240118D: AstroSat CZTI detection
  35. GRB 240117A: AstroSat CZTI detection
  36. GRB 240117A: Glowbug gamma-ray detection
  37. GRB 240118A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  38. Konus-Wind detection of GRB 240118A
  39. GRB 240118A: NuSTAR Detection of a Long GRB
  40. GRB 240118B: Fermi GBM Final Real-time Localization
  41. GRB 240118A: Fermi-LAT detection
  42. GRID detection of GRB 231230A
  43. GRB 240118A: Fermi GBM Final Real-time Localization
  44. GRB 240115A: Swift/BAT-GUANO detection of a short burst
  45. IPN triangulation of GRB 240112A (long)
  46. GRB 240115B: AstroSat CZTI detection
  47. GRB 240115B: Fermi GBM Detection
  48. IceCube-240105A: ZTF optical observation of blazar PKS 0446+11
  49. GRB 240112D: Glowbug gamma-ray detection
  50. GRB 240112C: Glowbug gamma-ray detection
  51. GRB 240112C: VZLUSAT-2 detection
  52. GRB 240107A: VZLUSAT-2 detection
  53. GRB 240115B: Fermi GBM Final Real-time Localization
  54. Konus-Wind detection of GRB 240112C
  55. GRB 240115A: Fermi GBM Final Real-time Localization
  56. GRB 240112C: GRBAlpha detection
  57. GRB 240114A: MAXI/GSC detection
  58. GRB 240112C: Swift/UVOT Detection
  59. GRB 240112C: Fermi GBM Detection
  60. GRB 240112E: Fermi GBM Final Localization
  61. GRB 240112D: Fermi GBM Final Real-time Localization
  62. GRB 240112C: Swift detection of a burst with an optical counterpart
  63. GRB 240112B: Fermi GBM Final Real-time Localization
  64. GRB 240112A: GECAM detection of a burst
  65. GRB 240110A: AstroSat CZTI detection
  66. Fermi-LAT detection of increased gamma-ray activity of blazar PKS 0446+11, located inside the IceCube-240105A error region
  67. GRB 240108A: Glowbug gamma-ray detection
  68. GRB 240106B: Glowbug gamma-ray detection
  69. GRB 240106A: Glowbug gamma-ray detection
  70. GRB 240109B: Fermi GBM Final Real-time Localization
  71. Konus-Wind detection of GRB 240101C
  72. GRB 231215A: radio detection with the VLA
  73. GRB 230812B: further radio observations with the VLA
  74. GRB 240107A: AstroSat CZTI detection
  75. GRB 240109A: Swift detection of a short burst
  76. IceCube-240105A: JCMT SCUBA2 Detection of Two Bright Submillimeter Sources
  77. GRB 240106A: GRBAlpha detection
  78. GRB 240107A: MAXI/GSC detection
  79. GRB 240106B: Fermi GBM Final Real-time Localization
  80. GRB 240106A: Fermi GBM Final Real-time Localization
  81. IPN triangulation of GRB 240101C (short)
  82. GRB 240101A: 1.3m DFOT optical observations
  83. IceCube-240105A - IceCube observation of a high-energy neutrino candidate track-like event
  84. GRB 240102A: 1.3m DFOT optical upper limit
  85. GRB 240101B: 1.3m DFOT optical upper limit
  86. GRB 240101C: Swift/BAT-GUANO detection of a short burst
  87. GRB 240102C: AstroSat CZTI detection
  88. GRB 240101C: AstroSat CZTI detection
  89. GRB240102A: BOOTES-6/DPRT optical upper limit
  90. GRB 240102B: Fermi GBM Final Real-time Localization
  91. GRB 240102A: Swift detection of a burst
  92. GRB 240101C: GRBAlpha detection
  93. GRB 240101C: Fermi GBM Final Localization
  94. GRB 240101B: Swift detection of a burst
  95. GRB 240101A: Swift detection of a burst
  96. GRB 231230A: Swift detection of a burst
  97. GRB 231230A: Fermi GBM Final Real-time Localization
  98. GRB 231210B: BOOTES-7 optical upper limit
  99. IPN triangulation of GRB 231224A (short)
  100. GRB 231224A: Fermi GBM Final Real-time Localization

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