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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"

36343 results found.

  1. GRB 240101A: 1.3m DFOT optical observations
  2. GRB 240102A: 1.3m DFOT optical upper limit
  3. GRB 240101B: 1.3m DFOT optical upper limit
  4. GRB 240101C: Swift/BAT-GUANO detection of a short burst
  5. GRB 240102C: AstroSat CZTI detection
  6. GRB 240101C: AstroSat CZTI detection
  7. GRB 231220A: Swift-UVOT upper limit
  8. GRB 240102A: Swift-BAT refined analysis
  9. GRB 240102A: Swift/UVOT Upper Limits
  10. GRB 231230A: Swift-BAT refined analysis
  11. GRB 240101A: Swift-BAT refined analysis
  12. GRB 240101B: Swift-BAT refined analysis
  13. GRB 240102A: Enhanced Swift-XRT position
  14. GRB 240101B: Swift-XRT refined Analysis
  15. GRB 240102A: Swift-XRT refined Analysis
  16. GRB 240102B (Fermi GBM trigger 725926335/240102925) is not a GRB
  17. GRB 240102A: LCOGT Optical Upper Limits
  18. GRB240102A: BOOTES-6/DPRT optical upper limit
  19. GRB 240102B: Fermi GBM Final Real-time Localization
  20. GRB 240101B: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  21. GRB 240102A: Swift detection of a burst
  22. GRB 240101A: Terskol Zeiss-2000 optical observations
  23. GRB 240101C: GRBAlpha detection
  24. GRB 240101B: Swift/UVOT Upper Limits
  25. GRB 240101A: Swift/UVOT Upper Limits
  26. GRB 240101A: Swift-XRT refined Analysis
  27. GRB 240101B: Enhanced Swift-XRT position
  28. GRB 240101B: KAIT Optical Upper Limit
  29. GRB 240101A: KAIT Optical Upper Limit
  30. GRB 240101A: Enhanced Swift-XRT position
  31. GRB 240101C: Fermi GBM Final Localization
  32. GRB 240101B: Swift detection of a burst
  33. GRB 240101A: Swift detection of a burst
  34. GRB231230A: Fermi GBM Observation
  35. GRB 231230A: Swift-XRT refined Analysis
  36. GRB 231230A: GOTO optical upper limits
  37. GRB 231230A: Enhanced Swift-XRT position
  38. GRB 231230A: Swift/UVOT Upper Limits
  39. GRB 231230A: NOT optical upper limits
  40. GRB 231230A: Prompt enhanced Swift-XRT position
  41. GRB 231230A: Swift detection of a burst
  42. GRB 231230A: Fermi GBM Final Real-time Localization
  43. GRB 231210B: BOOTES-7 optical upper limit
  44. LIGO/Virgo/KAGRA S231224e: Upper limits from Swift/BAT-GUANO
  45. IPN triangulation of GRB 231224A (short)
  46. GRB 231224A: Fermi GBM Final Real-time Localization
  47. GRB 231222B: GRBAlpha detection
  48. GRB 231222B: Swift-XRT afterglow detection
  49. GRB 231222B: Fermi GBM Detection
  50. GRB 231222B: Fermi-LAT detection
  51. GRB 231222A: Tiled Swift observations
  52. GRID detection of GRB 231215A
  53. GRB 231222A: Fermi GBM Final Real-time Localization
  54. GRB 231220A: Swift-XRT follow-up observations
  55. GRB 231220A: Swift ToO observations
  56. GRB 231220A: Swift/BAT-GUANO arcminute localization of a long burst
  57. GRB 231220A: Fermi GBM Final Real-time Localization
  58. GRB 231210B: new optical transient detected with the Greenhill Observatory University of Tasmania within the BAT-Swift enhanced position
  59. GRB 231219A: Fermi GBM Final Real-time Localization
  60. GRID detection of GRB 231205B
  61. GRID detection of GRB 231205A
  62. GRB 231216A: GAD Observatory, La Spezia, Italy upper limit
  63. GRB 231214B: Fermi GBM observation
  64. GRB 231216A: optical upper limits from the INAF Asiago Observatory
  65. GRB 231216A: 10.4 m GTC optical upper limit
  66. GRB 231215A: AMI-LA radio detection
  67. GRB 231216A: Nanshan/HMT optical upper limit
  68. GRB 231216A: LCOGT Optical Upper Limits
  69. GRB 231216A: Osservatorio Astronomico Nastro Verde upper limit
  70. GRB 231216A: Swift-XRT refined analysis correction
  71. GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
  72. GRB 231216A: Swift-XRT refined Analysis
  73. GRB 231216A: AST3-3 YaoAn Optical Upper Limit
  74. GRB 231216A: REM NIR upper limits
  75. GRB 231216A: Swift/UVOT Upper Limits
  76. GRB 231216A: Swift-BAT refined analysis
  77. GRB 231215A: Swift-BAT refined analysis
  78. GRB 231214A: Swift-BAT refined analysis
  79. GRB 231216A: R-band observations from T120 at Observatoire de Haute-Provence
  80. GRB 231216A: GIT optical upper limit
  81. GRB 231216A: NOT optical upper limits
  82. GRB 231216A: BOOTES-2/TELMA optical upper limit
  83. GRB 231215A: GRBAlpha detection
  84. GRB 231216A: Swift detection of a burst
  85. Konus-Wind detection of GRB 231215A
  86. GRB 231215A: optical afterglow detection from the INAF Asiago Observatory
  87. GRB 231215A: NOT optical observations
  88. GRB 231214A: Swift/UVOT Upper Limits
  89. GRB 231215A: Redshift from OSIRIS+ / GTC
  90. GRB 231205B: VZLUSAT-2 detection
  91. GRB 231204A: VZLUSAT-2 detection
  92. GRB 231215A: GAD Observatory, La Spezia, Italy upper limit;
  93. GRB 231215A: Fermi GBM observation
  94. GRB 231215A: CALET Gamma-Ray Burst Monitor detection
  95. GRB 231215A : OHP/T193 optical afterglow detection
  96. GRB 231215A: Swift/UVOT Detection
  97. GRB 231215A: Swift-XRT refined Analysis
  98. GRB 231215A: BOOTES-4/MET optical detection
  99. GRB 231215A: AKO Optical Upper Limit
  100. GRB 231215A: AGILE detection

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