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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"

28256 results found.

  1. GRB 230207B: Swift/BAT-GUANO detection outside the coded FOV
  2. ZTF23aabmzlp/AT2023azs: Neil Gehrels Swift Observatory X-ray observations
  3. GRB 230207B: AGILE detection of a burst
  4. GRB 230207A: Fermi GBM Final Real-time Localization
  5. GRB 230204B: Swift/UVOT Upper Limits
  6. GRB 230205A: Swift/UVOT Upper Limits
  7. GRB 230204B: Fermi GBM detection
  8. GRB 230205A: LCOGT Optical Upper Limits
  9. GRB 230204B: Swift-XRT afterglow detection
  10. GRB 230204B: 3.6m DOT optical observation
  11. GRB 230205A: SVOM/C-GFT optical upper limit
  12. GRB 230204B: VLT/X-shooter redshift
  13. GRB 230204B: ATLAS detection of the optical afterglow and a projected location in a nearby galaxy group
  14. GRB 230205A: Swift-XRT refined Analysis
  15. GRB 230204B: Swift ToO observations
  16. GRB 230205A: Enhanced Swift-XRT position
  17. GRB 230205A: BOOTES-5/JGT early optical upper limit
  18. GRB 230204B: Detection by GRBAlpha
  19. GRB 230204B: AGILE detection
  20. GRB 230205A: Swift detection of a burst
  21. GRB 230204B: GIT discovery of the likely optical afterglow
  22. GRB 230204B: AstroSat CZTI detection
  23. GRB 230204B: Swift/BAT-GUANO detection outside the coded FOV
  24. GRB 230204A: Swift/UVOT Upper Limits
  25. GRB 230204B: MAXI/GSC detection
  26. GRB 230204A: Swift-XRT refined Analysis
  27. GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
  28. GRB 230204A: Enhanced Swift-XRT position
  29. GRB 230204A: Swift detection of a possible burst (or possible transient Swift J1552.8-5055)
  30. ZTF23aabmzlp/AT2023azs: Lulin 1m LOT optical observations
  31. ZTF23aabmzlp/AT2023azs: VLA radio detection
  32. ZTF23aaarlti/AT2023avj: AMI-LA radio detection
  33. ZTF23aabmzlp/AT2023azs: AMI-LA radio upper limit
  34. GRB 230201B: Fermi GBM Final Real-time Localization
  35. GRB 230126A: Detection by VZLUSAT-2
  36. IceCube-230201A - IceCube observation of a high-energy neutrino candidate track-like event
  37. GRB 221009A: radio afterglow detection with the EVN
  38. GRB 230201A: Fermi GBM Final Real-time Localization
  39. ZTF23aabmzlp/AT2023azs: LCOGT Optical Detection
  40. ZTF23aaarlti/AT2023avj: Assy continued optical observations
  41. AT2023avj: X-ray Detection with Swift/XRT
  42. ZTF23aabmzlp/AT2023azs: 1.3m DFOT optical observations
  43. GRB 230129A: AstroSat CZTI detection
  44. GRB 230128A: AstroSat CZTI detection
  45. GRB 230130A: Fermi GBM Final Real-time Localization
  46. ZTF23aaarlti/AT2023avj: VLA radio detection
  47. GRB 230129A: Fermi GBM Final Real-time Localization
  48. GRB 230128A: Fermi GBM Final Real-time Localization
  49. ZTF23aabmzlp/AT2023azs: GIT confirmation of the likely afterglow
  50. ZTF23aabmzlp/AT2023azs: Zwicky Transient Facility discovery of a fast optical transient
  51. AT2023avj ZTF Candidate: Assy optical observations
  52. ZTF and LT Observations of AT2023avj, a Candidate Optical Afterglow
  53. GRB 230126A: Fermi GBM Final Real-time Localization
  54. Swift-XRT observations of NuEm-230125A
  55. Trigger 1150965: Swift detection of LS V +44 17
  56. GRB 230124A: Swift/BAT-GUANO detection outside the coded FOV
  57. GRB 230114B: Detection by VZLUSAT-2
  58. GRB 230123A: LCOGT Optical Upper Limits
  59. GRB 230124A: Fermi GBM Final Real-time Localization
  60. GRB 230122A: Swift/BAT-GUANO detection
  61. GRB 230123A: Swift/UVOT Upper Limits
  62. GRB 230123A: Swift-XRT refined Analysis
  63. GRB 230123A: Enhanced Swift-XRT position
  64. GRB 230123A: Zadko observatory - Gingin optical observations
  65. GRB 230116C: Swift-XRT observations
  66. GRB 230123A: Swift detection of a burst
  67. IceCube-230122A - IceCube observation of a high-energy neutrino candidate track-like event
  68. Trigger 1150107: Swift detection of LS V +44 17
  69. GRB 230120A: AstroSat CZTI detection
  70. IPN triangulation of GRB 230116B (short)
  71. GRB 230119A: CALET Gamma-Ray Burst Monitor detection
  72. GRB 230116D: 3.6m DOT optical upper limit
  73. GRB 230119A: Fermi GBM Final Real-time Localization
  74. GRB 230118A: Fermi GBM Final Real-time Localization
  75. GRB 230116D: SAO RAS further observations
  76. GRB 230116D: SAO RAS photometry
  77. GRB 230116D: KGO RC-25 optical observations
  78. GRB 230116D: Sintez-Newton/CrAO optical observations
  79. GRB 230116D: LCOGT Optical Upper Limit
  80. GRB 230116D: SAO RAS redshift
  81. GRB 230116D: Swift-XRT refined Analysis
  82. GRB 230117A: Fermi GBM Final Real-time Localization
  83. GRB 230116D: GIT optical follow-up
  84. GRB 230116D: Enhanced Swift-XRT position
  85. GRB 230116D: SAO RAS observations of OT brightening
  86. GRB 230116D: Sintez-Newton/CrAO optical afterglow detection
  87. GRB 230116D: Nanshan/NEXT optical afterglow detection
  88. GRB 230116D: Swift detection of a burst
  89. GRB 230116C: Swift detection of a burst
  90. GRB 230116B: Fermi GBM Final Real-time Localization
  91. GRB 230116A: Fermi GBM Final Real-time Localization
  92. GRB 230114A: Detection by VZLUSAT-2
  93. GRB 230114A: Fermi GBM Final Real-time Localization
  94. Trigger 1148770: Swift detection of Cyg X-1 due to Star Tracker loss of lock
  95. IceCube-230112A - IceCube observation of a high-energy neutrino candidate track-like event
  96. GRB 230112A: Fermi GBM Final Real-time Localization
  97. GRB 230111A: MAXI/GSC detection
  98. GRB 230111A: Fermi GBM Final Real-time Localization
  99. GRB 230106: AstroSat LAXPC detection
  100. GRB 221231A: 3.6m DOT optical upper limit

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