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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

19725 results found.

  1. GRB 221216A: Nanshan/NEXT optical upper limits
  2. GRB 221216A: Swift detection of a burst
  3. GRB 221215A: Swift ToO observations
  4. Konus-Wind detection of a burst from SGR 1935+2154 on 2022 December 13
  5. GRB 221209A: AstroSat CZTI detection
  6. GRB 221206B: Fermi GBM observation
  7. GRB 221206B: Swift-XRT observations
  8. GRB 221206B: Detection by GRBAlpha
  9. GRB 221206B: Swift ToO observations
  10. GRB 221202A: Swift/UVOT Detection
  11. GRB 221202A: VLT/FORS2 Afterglow Discovery
  12. GRB 221202A: Swift-XRT refined Analysis
  13. GRB 221202A: LCOGT Optical Upper Limits
  14. GRB 221202A: Enhanced Swift-XRT position
  15. GRB 221202A: MeerLICHT upper limits
  16. GRB 221202A: Swift detection of a burst
  17. GCN: GRB 221201A: Swift/UVOT Upper Limits
  18. GRB 221201A: Enhanced Swift-XRT position
  19. GRB 221201A: Swift detection of a burst
  20. Optical polarization observation of GRB 221009A
  21. GRB 221126A: Fermi GBM observation
  22. IceCube-221124A: BOOTES-4/MET and BOOTES-2/TELMA optical upper limit
  23. Alert from the HAWC Burst Monitor HAWC-221128A
  24. IPN triangulation of GRB 221124A (long)
  25. GRB 221124A: Swift/BAT-GUANO detection
  26. Fermi-LAT gamma-ray observations of IceCube-221124A
  27. GRB 221120A: TURBO Optical Upper Limit
  28. GRB 221120A: VIRT Optical Upper Limit
  29. Alert from the HAWC Burst Monitor HAWC-221123A
  30. IPN triangulation of GRB 221121A (long)
  31. GRB221120A: WIRC near-IR imaging of the afterglow candidate
  32. GRB 221120A: Enhanced Swift-XRT position
  33. GRB221120A: Montarrenti Observatory Upper Limit
  34. GRB 221120A: Swift/UVOT Upper Limits
  35. GRB 221120A: GIT upper limits on optical afterglow
  36. GRB 221120A: Swift detection of a likely short burst
  37. GRB 221119A: Fermi-LAT detection
  38. GRB 221009A: Japanese VLBI Network observation
  39. GRB 221115B: LCOGT Optical Upper Limits
  40. GRB 221115B : MeerLICHT upper limits
  41. GRB 221110A: GRANDMA observations
  42. GRB 221110A: COATLI Second-Epoch Upper Limits
  43. GRB 221009A: GRANDMA/Kilonova-Catcher observations
  44. GRB 221110A: GMG upper limit
  45. GRB 221110A: Swift/UVOT Detection and Corrected UVOT Position
  46. GRB 221110A: Swift-XRT refined Analysis
  47. GRB 221110A: Enhanced Swift-XRT position
  48. GRB 221110A: COATLI Afterglow detection
  49. GRB 221110A: LCOGT Optical Afterglow Detection
  50. GRB 221110A: Swift detection of a burst with an optical counterpart
  51. GRB 221009A: Hubble Space Telescope observations
  52. GRB 221108A: Fermi GBM Final Localization
  53. Fermi-LAT gamma-ray observations of IceCube-221104A
  54. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  55. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  56. GRB 221028A: CrAO/ZTSh optical upper limit
  57. GRB 221028A: COATLI Upper Limits
  58. Trigger 1132968: Swift trigger is the Crab
  59. GRB 221028A: MITSuME Okayama optical upper limits
  60. GRB 221028A: LCOGT Optical Upper Limits
  61. GRB 221027B: COATLI Upper Limits
  62. GRB 221028A: BOOTES-4/MET optical upper limit
  63. GRB 221028A: GIT optical upper limit
  64. GRB 221027B: Swift/UVOT Upper Limits
  65. GRB 221028A: Swift detection of a burst
  66. GRB 221027B: Swift-XRT refined Analysis
  67. GRB 221027B: Enhanced Swift-XRT position
  68. GRB 221027B: Swift detection of a burst
  69. GRB 221024A: Mondy optical observations
  70. GRB 221024A: GRANDMA observations
  71. IPN triangulation of GRB 221022C (short)
  72. GRB 221025A: AstroSat CZTI detection
  73. GRB 221009A: SARA-RM 1m Optical Afterglow Detection
  74. GRB 221024A: Swift/UVOT UV upper limits
  75. GRB 221024A: Swift-XRT refined Analysis
  76. IPN triangulation of GRB 221022B (long)
  77. GRB 221024A: GIT confirmation of the optical afterglow
  78. GRB 221024A: Enhanced Swift-XRT position
  79. GRB 221024A: D50 candidate afterglow
  80. GRB 221022A: Swift ToO observations
  81. GRB 221024A: Swift detection of a burst
  82. GRB221009A: LBT optical imaging
  83. GRB 221009A: Peak luminosity of the supernova vs. synchrotron afterglow
  84. GRB 221009A: TNG NIR detection
  85. GRB 221009A: BOAO NIR detections
  86. GRB 221009A: Spectroscopic detection of emerging SN features
  87. GRB 221009A: GRANDMA observations
  88. GRB 221017A: Swift ToO observations
  89. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  90. GRB 221016A: Swift/UVOT Detection
  91. GRB 220926B: Detection by GRBAlpha
  92. GRB 221016A: z-band upper limit, possible afterglow brightening
  93. GRB 221016A: Enhanced Swift-XRT position
  94. GRB 221016A: LCOGT Optical Afterglow Detection
  95. GRB 221016A: Swift detection of a burst
  96. GRB 221009A: Faulkes Telescope North continued optical afterglow follow-up
  97. Konus-Wind observation of the recent SGR 1935+2154 activity
  98. GRB 221009A: ALMA and ACA detections
  99. GRB 221009A: Large Binocular Telescope Observatory optical afterglow detection
  100. MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946

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