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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"

38354 results found.

  1. GRB 240108A: Glowbug gamma-ray detection
  2. GRB 231214A: ATCA Radio Upper Limits
  3. GRB 240106B: Glowbug gamma-ray detection
  4. GRB 240106A: Glowbug gamma-ray detection
  5. GRB 240109B: Fermi GBM Final Real-time Localization
  6. IceCube-240105A: Three candidates from the Zwicky Transient Facility
  7. Konus-Wind detection of GRB 240101C
  8. GRB 231215A: radio detection with the VLA
  9. GRB 230818A: further radio observations with the VLA
  10. GRB 230812B: further radio observations with the VLA
  11. Swift GRB240109.17: Global MASTER-Net observations report
  12. GRB 240107A: AstroSat CZTI detection
  13. GRB 240109A: Swift detection of a short burst
  14. LIGO/Virgo/KAGRA S240104bl: Upper limits from Swift/BAT-GUANO
  15. IceCube-240105A: JCMT SCUBA2 Detection of Two Bright Submillimeter Sources
  16. Update of IceCube-240105A - Corrected errors
  17. GRB 240106A: GRBAlpha detection
  18. GRB 240107A: MAXI/GSC detection
  19. Fermi trigger No 726347794: Global MASTER-Net observations report
  20. GRB 240106B: Fermi GBM Final Real-time Localization
  21. Fermi trigger No 726194053: Global MASTER-Net observations report
  22. GRB 240106A: Fermi GBM Final Real-time Localization
  23. IPN triangulation of GRB 240101C (short)
  24. GRB GRB240101C: Fermi GBM observation
  25. IceCube Alert 240105.52: Global MASTER-Net observations report
  26. GRB 240101A: 1.3m DFOT optical observations
  27. IceCube-240105A - IceCube observation of a high-energy neutrino candidate track-like event
  28. GRB 240102A: 1.3m DFOT optical upper limit
  29. GRB 240101B: 1.3m DFOT optical upper limit
  30. GRB 240101C: Swift/BAT-GUANO detection of a short burst
  31. GRB 240102C: AstroSat CZTI detection
  32. GRB 240101C: AstroSat CZTI detection
  33. GRB 231220A: Swift-UVOT upper limit
  34. GRB 240102A: Swift-BAT refined analysis
  35. GRB 240102A: Swift/UVOT Upper Limits
  36. GRB 231230A: Swift-BAT refined analysis
  37. GRB 240101A: Swift-BAT refined analysis
  38. GRB 240101B: Swift-BAT refined analysis
  39. GRB 240102A: Enhanced Swift-XRT position
  40. GRB 240101B: Swift-XRT refined Analysis
  41. GRB 240102A: Swift-XRT refined Analysis
  42. GRB 240102B (Fermi GBM trigger 725926335/240102925) is not a GRB
  43. GRB 240102A: LCOGT Optical Upper Limits
  44. Fermi trigger No 725857207: Global MASTER-Net observations report
  45. GRB240102A: BOOTES-6/DPRT optical upper limit
  46. GRB 240102B: Fermi GBM Final Real-time Localization
  47. GRB 240101B: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  48. GRB 240102A: Swift detection of a burst
  49. GRB 240101A: Terskol Zeiss-2000 optical observations
  50. GRB 240101C: GRBAlpha detection
  51. GRB 240101B: Swift/UVOT Upper Limits
  52. GRB 240101A: Swift/UVOT Upper Limits
  53. GRB 240101A: Swift-XRT refined Analysis
  54. GRB 240101B: Enhanced Swift-XRT position
  55. GRB 240101B: KAIT Optical Upper Limit
  56. GRB 240101A: KAIT Optical Upper Limit
  57. GRB 240101A: Enhanced Swift-XRT position
  58. GRB 240101C: Fermi GBM Final Localization
  59. Swift GRB240101.85: Global MASTER-Net observations report
  60. GRB 240101B: Swift detection of a burst
  61. GRB 240101A: Swift detection of a burst
  62. Fermi trigger No 725806648: Global MASTER-Net observations report
  63. GRB231230A: Fermi GBM Observation
  64. GRB 231230A: Swift-XRT refined Analysis
  65. GRB 231230A: GOTO optical upper limits
  66. GRB 231230A: Enhanced Swift-XRT position
  67. GRB 231230A: Swift/UVOT Upper Limits
  68. GRB 231230A: NOT optical upper limits
  69. Fermi trigger No 725592555: Global MASTER-Net observations report
  70. GRB 231230A: Prompt enhanced Swift-XRT position
  71. GRB 231230A: Swift detection of a burst
  72. Swift GRB231230.06: Global MASTER-Net observations report
  73. GRB 231230A: Fermi GBM Final Real-time Localization
  74. GRB 231210B: BOOTES-7 optical upper limit
  75. LIGO/Virgo/KAGRA S231224e: Upper limits from Swift/BAT-GUANO
  76. IPN triangulation of GRB 231224A (short)
  77. Fermi trigger No 725143760: Global MASTER-Net observations report
  78. GRB 231224A: Fermi GBM Final Real-time Localization
  79. GRB 231222B: GRBAlpha detection
  80. GRB 231222B: Swift-XRT afterglow detection
  81. Fermi trigger No 724921799: Global MASTER-Net observations report
  82. GRB 231222B: Fermi GBM Detection
  83. LAT GRB231222.31: Global MASTER-Net observations report
  84. GRB 231222B: Fermi-LAT detection
  85. GRB 231222A: Tiled Swift observations
  86. GRID detection of GRB 231215A
  87. GRB 231222A: Fermi GBM Final Real-time Localization
  88. GRB 231220A: Swift-XRT follow-up observations
  89. GRB 231220A: Swift ToO observations
  90. GRB 231220A: Swift/BAT-GUANO arcminute localization of a long burst
  91. Fermi trigger No 724781422: Global MASTER-Net observations report
  92. GRB 231220A: Fermi GBM Final Real-time Localization
  93. GRB 231210B: new optical transient detected with the Greenhill Observatory University of Tasmania within the BAT-Swift enhanced position
  94. Fermi trigger No 724698747: Global MASTER-Net observations report
  95. GRB 231219A: Fermi GBM Final Real-time Localization
  96. GRID detection of GRB 231205B
  97. GRID detection of GRB 231205A
  98. GRB 231216A: GAD Observatory, La Spezia, Italy upper limit
  99. GRB 231214B: Fermi GBM observation
  100. GRB 231216A: optical upper limits from the INAF Asiago Observatory

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