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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"

21983 results found.

  1. GRB 240205B: MASTER OT J232550.14-550704.6 counterpart detection
  2. GRB 240205B: Swift detection of a burst
  3. Swift GRB240205.93: Global MASTER-Net observations report
  4. GRB 240204a: Liverpool Telescope optical afterglow detection
  5. GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
  6. Fermi trigger No 728796365: Global MASTER-Net observations report
  7. GRB 240204A: Montarrenti Observatory optical observations
  8. Fermi GRB 240204A: Global MASTER-Net observations report
  9. Fermi trigger No 728706420: Global MASTER-Net observations report
  10. IceCube Alert 240204.38: Global MASTER-Net observations report
  11. GRB 240129A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  12. GRB 240128A: Swift-XRT observations
  13. GRB 240128A: Tiled Swift observations
  14. Fermi GRB 240127A: Global MASTER-Net observations report
  15. GRB 240122A: ATCA detection of radio counterpart
  16. GRB240122A: PRIME near infrared detection
  17. GRB 240123B: Swift/BAT-GUANO detection of a long burst
  18. Fermi-LAT gamma-ray observations of IceCube-240123A
  19. GRB 240123A: further SAO RAS optical observations
  20. IceCube Alert 240123.48: Global MASTER-Net observations report
  21. GRB 240123A: Mondy continued optical observations and the PL decay index
  22. GRB 240123A: SAO RAS optical observations
  23. Fermi GRB 240123B: Global MASTER-Net observations report
  24. GRB 240122A: Swift/UVOT Upper Limits
  25. Fermi GBM Sub-Threshold Detection of GRB 240123A
  26. GRB 240123A: Mondy continued optical observations + correction of the GRB name in GCN 35605
  27. GRB 240118A: Swift/UVOT Upper Limits
  28. GRB 240123A: Mondy optical afterglow observations
  29. Swift GRB240123.46: Global MASTER-Net observations report
  30. GRB 240122A: Swift-XRT afterglow detection
  31. GRB 240122A: VLT/X-shooter redshift confirmation
  32. GRB 240122A: LT non-detection of GOTO candidate counterpart confirms fading
  33. GRB 240122A: GOTO optical counterpart candidate
  34. GRB 240122A: Tiled Swift observations
  35. GRB 240118A: Mondy optical observations
  36. GRB 240118A: Swift-XRT afterglow detection
  37. Fermi GRB 240119A: Global MASTER-Net observations report
  38. IceCube-240105A: Detection of NIR flare of PKS 0446+11 with WINTER
  39. GRB 240118C: Swift/BAT-GUANO detection of a burst
  40. GRB 240118A: Swift ToO observations
  41. Fermi GRB 240118B: Global MASTER-Net observations report
  42. GRB 240118A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  43. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-240118A
  44. LAT GRB240118.08: Global MASTER-Net observations report
  45. GRB 240115A: Swift/BAT-GUANO detection of a short burst
  46. LIGO/Virgo/KAGRA S240109a: Upper limits from Swift/BAT-GUANO
  47. Integral GRB240115.70: Global MASTER-Net observations report
  48. Fermi GRB 240115B: Global MASTER-Net observations report
  49. Fermi GRB 240115A: Global MASTER-Net observations report
  50. GRB 240112C: Swift/UVOT Detection
  51. Fermi trigger No 726773850: Global MASTER-Net observations report
  52. GRB 240112C: SAO RAS optical observations
  53. Fermi GRB 240112D: Global MASTER-Net observations report
  54. Fermi trigger No 726774492: Global MASTER-Net observations report
  55. Swift GRB 240112C: Global MASTER-Net observations report
  56. Fermi GRB 240112B: Global MASTER-Net observations report
  57. Fermi-LAT detection of increased gamma-ray activity of blazar PKS 0446+11, located inside the IceCube-240105A error region
  58. GRB 231214A: ATCA Radio Upper Limits
  59. IceCube-240105A: Three candidates from the Zwicky Transient Facility
  60. GRB 231215A: radio detection with the VLA
  61. GRB 230818A: further radio observations with the VLA
  62. GRB 230812B: further radio observations with the VLA
  63. Swift GRB240109.17: Global MASTER-Net observations report
  64. LIGO/Virgo/KAGRA S240104bl: Upper limits from Swift/BAT-GUANO
  65. IceCube-240105A: JCMT SCUBA2 Detection of Two Bright Submillimeter Sources
  66. Fermi trigger No 726347794: Global MASTER-Net observations report
  67. Fermi trigger No 726194053: Global MASTER-Net observations report
  68. IceCube Alert 240105.52: Global MASTER-Net observations report
  69. GRB 240101A: 1.3m DFOT optical observations
  70. GRB 240102A: 1.3m DFOT optical upper limit
  71. GRB 240101B: 1.3m DFOT optical upper limit
  72. GRB 240101C: Swift/BAT-GUANO detection of a short burst
  73. GRB 231220A: Swift-UVOT upper limit
  74. GRB 240102A: Swift/UVOT Upper Limits
  75. Fermi trigger No 725857207: Global MASTER-Net observations report
  76. GRB 240101B: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  77. GRB 240101A: Terskol Zeiss-2000 optical observations
  78. GRB 240101B: Swift/UVOT Upper Limits
  79. GRB 240101A: Swift/UVOT Upper Limits
  80. Swift GRB240101.85: Global MASTER-Net observations report
  81. Fermi trigger No 725806648: Global MASTER-Net observations report
  82. GRB 231230A: GOTO optical upper limits
  83. GRB 231230A: Swift/UVOT Upper Limits
  84. GRB 231230A: NOT optical upper limits
  85. Fermi trigger No 725592555: Global MASTER-Net observations report
  86. Swift GRB231230.06: Global MASTER-Net observations report
  87. LIGO/Virgo/KAGRA S231224e: Upper limits from Swift/BAT-GUANO
  88. Fermi trigger No 725143760: Global MASTER-Net observations report
  89. GRB 231222B: Swift-XRT afterglow detection
  90. Fermi trigger No 724921799: Global MASTER-Net observations report
  91. LAT GRB231222.31: Global MASTER-Net observations report
  92. GRB 231222A: Tiled Swift observations
  93. IceCube-231211A: GRANDMA observations of PKS2047+098
  94. GRB 231220A: Swift-XRT follow-up observations
  95. GRB 231220A: Swift ToO observations
  96. GRB 231220A: Swift/BAT-GUANO arcminute localization of a long burst
  97. Fermi trigger No 724781422: Global MASTER-Net observations report
  98. GRB 231210B: new optical transient detected with the Greenhill Observatory University of Tasmania within the BAT-Swift enhanced position
  99. Fermi trigger No 724698747: Global MASTER-Net observations report
  100. GRB 231216A: GAD Observatory, La Spezia, Italy upper limit

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