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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"

39400 results found.

  1. GRB 230207A: Fermi GBM Final Real-time Localization
  2. GRB 230204B: LCOGT Optical Upper Limits
  3. GRB 230204B: Swift/UVOT Upper Limits
  4. Fermi trigger No 697403223: Global MASTER-Net observations report
  5. Fermi trigger No 697396830: Global MASTER-Net observations report
  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 230205A: OHP/T193 optical observations
  13. GRB 230204B: VLT/X-shooter redshift
  14. GRB 230205A: Swift-BAT refined analysis (T90 = 2.3 s)
  15. GRB 230204A: Swift-BAT refined analysis
  16. GRB 230204B: ATLAS detection of the optical afterglow and a projected location in a nearby galaxy group
  17. GRB 230205A: Swift-XRT refined Analysis
  18. GRB 230204B: Swift ToO observations
  19. GRB 230205A: Enhanced Swift-XRT position
  20. GRB 230205A: BOOTES-5/JGT early optical upper limit
  21. GRB 230204B: Detection by GRBAlpha
  22. GRB 230204B: AGILE detection
  23. GRB 230205A: Swift detection of a burst
  24. IceCube-230201A: BOOTES-4/MET Optical Upper Limits
  25. GRB 230204B: GIT discovery of the likely optical afterglow
  26. GRB 230204B: AstroSat CZTI detection
  27. GRB 230204B: Swift/BAT-GUANO detection outside the coded FOV
  28. GRB 230204A: Swift/UVOT Upper Limits
  29. GRB 230204B: MAXI/GSC detection
  30. GRB 230204A: Swift-XRT refined Analysis
  31. GRB 230204A/Swift J1552.8-5055: LCOGT Optical Counterpart Candidate
  32. Fermi trigger No 697208885: Global MASTER-Net observations report
  33. GRB 230204A: Enhanced Swift-XRT position
  34. GRB 230204A: Swift detection of a possible burst (or possible transient Swift J1552.8-5055)
  35. GRB 230201B: TURBO Optical Upper Limits
  36. Fermi Gamma-ray Burst Monitor trigger 230203275 / 697098930 is not a GRB
  37. Fermi trigger No 697098930: Global MASTER-Net observations report
  38. GRB 221216A: Swift-BAT refined analysis
  39. IceCube Alert 230201.26: Global MASTER-Net observations report
  40. Fermi GRB 230201B: Global MASTER-Net observations report
  41. Fermi-LAT gamma-ray observations of IceCube-230201A
  42. GRB 230201B: Fermi GBM Final Real-time Localization
  43. GRB 230126A: Detection by VZLUSAT-2
  44. Fermi GRB 230201A: Global MASTER-Net observations report
  45. IceCube-230201A - IceCube observation of a high-energy neutrino candidate track-like event
  46. GRB 221009A: radio afterglow detection with the EVN
  47. GRB 230201A: Fermi GBM Final Real-time Localization
  48. ZTF23aaarlti/AT2023avj: Assy continued optical observations
  49. ZTF23aabmzlp/AT2023azs: Mondy and AbAO optical observations
  50. AT2023avj: X-ray Detection with Swift/XRT
  51. ZTF23aabmzlp/AT2023azs: 1.3m DFOT optical observations
  52. GRB 230129A: AstroSat CZTI detection
  53. GRB 230128A: AstroSat CZTI detection
  54. GRB 230130A: Fermi GBM Final Real-time Localization
  55. GRB 230129A: Fermi GBM Final Real-time Localization
  56. GRB 230128A: Fermi GBM Final Real-time Localization
  57. ZTF23aabmzlp/AT2023azs: GIT confirmation of the likely afterglow
  58. ZTF23aabmzlp/AT2023azs: Zwicky Transient Facility discovery of a fast optical transient
  59. AT2023avj ZTF Candidate: Assy optical observations
  60. GRB 230126A: Fermi GBM Final Real-time Localization
  61. Trigger 1150965: Swift detection of LS V +44 17
  62. GRB 230124A: Fermi GBM Observation
  63. GRB 230124A: Swift/BAT-GUANO detection outside the coded FOV
  64. GRB 230114B: Detection by VZLUSAT-2
  65. GRB 230123A: LCOGT Optical Upper Limits
  66. Fermi GRB 230124A: Global MASTER-Net observations report
  67. GRB 230124A: Fermi GBM Final Real-time Localization
  68. GRB 230123A: Swift-BAT refined analysis
  69. GRB 230122A: Swift/BAT-GUANO detection
  70. Fermi-LAT gamma-ray observations of IceCube-230122A
  71. GRB 230123A: Swift/UVOT Upper Limits
  72. GRB 230123A: Swift-XRT refined Analysis
  73. GRB 230123A: Enhanced Swift-XRT position
  74. GRB 230123A: Zadko observatory - Gingin optical observations
  75. GRB 230116C: Swift-XRT observations
  76. GRB 230123A: Swift detection of a burst
  77. IceCube Alert 230122.16: Global MASTER-Net observations report
  78. GRB 230116B: Fermi GBM observation
  79. Trigger 1150107: Swift detection of LS V +44 17
  80. GRB 230120A: AstroSat CZTI detection
  81. IPN triangulation of GRB 230116B (short)
  82. GRB 230119A: CALET Gamma-Ray Burst Monitor detection
  83. GRB 230116D: 3.6m DOT optical upper limit
  84. GRB 230119A: Fermi GBM Final Real-time Localization
  85. Fermi GRB 230118A: Global MASTER-Net observations report
  86. GRB 230118A: Fermi GBM Final Real-time Localization
  87. GRB 230116D: Swift-BAT refined analysis
  88. GRB 230116C: Swift-BAT refined analysis
  89. GRB 230116D: SAO RAS further observations
  90. GRB 230116D: SAO RAS photometry
  91. GRB 230116D: KGO RC-25 optical observations
  92. GRB 230116D: Sintez-Newton/CrAO optical observations
  93. GRB 230116D: LCOGT Optical Upper Limit
  94. GRB 230116D: SAO RAS redshift
  95. Fermi trigger No 695569700: Global MASTER-Net observations report
  96. GRB 230116D: Swift-XRT refined Analysis
  97. Fermi GRB 230117A: Global MASTER-Net observations report
  98. GRB 230117A: Fermi GBM Final Real-time Localization
  99. GRB 230116D: GIT optical follow-up
  100. GRB 230116D: GIT optical follow-up

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