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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').

17114 results found.

  1. GRB 240112C: Fermi GBM Detection
  2. GRB 240112C: Swift-XRT refined Analysis
  3. GRB 240112C: SAO RAS optical observations
  4. Swift GRB 240112C: Global MASTER-Net observations report
  5. GRB 240109A: Swift-BAT refined analysis
  6. GRB 240112C: Swift detection of a burst with an optical counterpart
  7. GRB 240109A: Fermi GBM Observation
  8. GRB 231214A: ATCA Radio Upper Limits
  9. Konus-Wind detection of GRB 240101C
  10. Swift GRB240109.17: Global MASTER-Net observations report
  11. GRB 240109A: Swift detection of a short burst
  12. LIGO/Virgo/KAGRA S240104bl: Upper limits from Swift/BAT-GUANO
  13. IPN triangulation of GRB 240101C (short)
  14. GRB GRB240101C: Fermi GBM observation
  15. GRB 240101A: 1.3m DFOT optical observations
  16. GRB 240102A: 1.3m DFOT optical upper limit
  17. GRB 240101B: 1.3m DFOT optical upper limit
  18. GRB 240101C: Swift/BAT-GUANO detection of a short burst
  19. GRB 231220A: Swift-UVOT upper limit
  20. GRB 240102A: Swift-BAT refined analysis
  21. GRB 240102A: Swift/UVOT Upper Limits
  22. GRB 231230A: Swift-BAT refined analysis
  23. GRB 240101A: Swift-BAT refined analysis
  24. GRB 240101B: Swift-BAT refined analysis
  25. GRB 240102A: Enhanced Swift-XRT position
  26. GRB 240101B: Swift-XRT refined Analysis
  27. GRB 240102A: Swift-XRT refined Analysis
  28. GRB 240102A: LCOGT Optical Upper Limits
  29. GRB240102A: BOOTES-6/DPRT optical upper limit
  30. GRB 240101B: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  31. GRB 240102A: Swift detection of a burst
  32. GRB 240101A: Terskol Zeiss-2000 optical observations
  33. GRB 240101B: Swift/UVOT Upper Limits
  34. GRB 240101A: Swift/UVOT Upper Limits
  35. GRB 240101A: Swift-XRT refined Analysis
  36. GRB 240101B: Enhanced Swift-XRT position
  37. GRB 240101B: KAIT Optical Upper Limit
  38. GRB 240101A: KAIT Optical Upper Limit
  39. GRB 240101A: Enhanced Swift-XRT position
  40. Swift GRB240101.85: Global MASTER-Net observations report
  41. GRB 240101B: Swift detection of a burst
  42. GRB 240101A: Swift detection of a burst
  43. GRB231230A: Fermi GBM Observation
  44. GRB 231230A: Swift-XRT refined Analysis
  45. GRB 231230A: GOTO optical upper limits
  46. GRB 231230A: Enhanced Swift-XRT position
  47. GRB 231230A: Swift/UVOT Upper Limits
  48. GRB 231230A: Prompt enhanced Swift-XRT position
  49. GRB 231230A: Swift detection of a burst
  50. Swift GRB231230.06: Global MASTER-Net observations report
  51. GRB 231210B: BOOTES-7 optical upper limit
  52. Swift Triggers 1205103, 1205104, 1205107 and 1205110 are not astrophysical events
  53. LIGO/Virgo/KAGRA S231224e: Upper limits from Swift/BAT-GUANO
  54. GRB 231222B: Swift-XRT afterglow detection
  55. GRB 231222B: Fermi-LAT detection
  56. GRB 231222A: Tiled Swift observations
  57. GRID detection of GRB 231215A
  58. GRB 231220A: Swift-XRT follow-up observations
  59. GRB 231220A: Swift ToO observations
  60. GRB 231220A: Swift/BAT-GUANO arcminute localization of a long burst
  61. GRB 231210B: new optical transient detected with the Greenhill Observatory University of Tasmania within the BAT-Swift enhanced position
  62. GRID detection of GRB 231205B
  63. GRB 231216A: GAD Observatory, La Spezia, Italy upper limit
  64. GRB 231214B: Fermi GBM observation
  65. GRB 231216A: 10.4 m GTC optical upper limit
  66. GRB 231216A: Nanshan/HMT optical upper limit
  67. GRB 231216A: LCOGT Optical Upper Limits
  68. GRB 231216A: Osservatorio Astronomico Nastro Verde upper limit
  69. GRB 231216A: Swift-XRT refined analysis correction
  70. GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
  71. GRB 231216A: Swift-XRT refined Analysis
  72. GRB 231216A: AST3-3 YaoAn Optical Upper Limit
  73. GRB 231216A: REM NIR upper limits
  74. GRB 231216A: Swift/UVOT Upper Limits
  75. GRB 231216A: Swift-BAT refined analysis
  76. GRB 231215A: Swift-BAT refined analysis
  77. GRB 231214A: Swift-BAT refined analysis
  78. GRB 231216A: R-band observations from T120 at Observatoire de Haute-Provence
  79. GRB 231216A: GIT optical upper limit
  80. GRB 231216A: BOOTES-2/TELMA optical upper limit
  81. GRB 231215A: GRBAlpha detection
  82. Swift GRB231216.77: Global MASTER-Net observations report
  83. GRB 231216A: Swift detection of a burst
  84. Konus-Wind detection of GRB 231215A
  85. GRB 231215A: NOT optical observations
  86. GRB 231214A: Swift/UVOT Upper Limits
  87. GRB 231205B: VZLUSAT-2 detection
  88. GRB 231215A: Fermi GBM observation
  89. GRB 231215A: CALET Gamma-Ray Burst Monitor detection
  90. GRB 231215A: Swift/UVOT Detection
  91. GRB 231215A: Swift-XRT refined Analysis
  92. GRB 231215A: BOOTES-4/MET optical detection
  93. GRB 231215A: AKO Optical Upper Limit
  94. GRB 231215A: AGILE detection
  95. GRB 231214A: Fermi GBM observation
  96. Konus-Wind detection of GRB 231210B
  97. GRB 231215A: Enhanced Swift-XRT position
  98. GRB 231214A: REM optical/NIR upper limits
  99. GRB 231215A: GROWTH-India optical follow-up
  100. GRB 231215A : Nanshan/HMT optical observations

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