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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"

22215 results found.

  1. GRB 210610A: Maidanak and AbAO optical observations
  2. GRB 210905A: REM NIR afterglow detection
  3. GRB 210905A: VLT/X-shooter spectroscopic redshift
  4. GRB 210905A: Continued LCO Optical Observations
  5. GRB 210901A: Swift/UVOT Upper Limits
  6. Swift GRB 210905A: Global MASTER-Net observations report
  7. Fermi GRB 210904A: Global MASTER-Net observations report
  8. Swift GRB210903.59: Global MASTER-Net observations report
  9. Swift GRB210903.58: Global MASTER-Net observations report
  10. Swift GRB210903.58: Global MASTER-Net observations report
  11. Fermi GRB 210903A: Global MASTER-Net observations report
  12. Fermi GRB 210903B: Global MASTER-Net observations report
  13. GRB 210901A: GROND observations
  14. Swift GRB 210901A: Global MASTER-Net observations report
  15. GRB 210827A: further Swift-XRT observations
  16. GRB 210827A: Swift/UVOT Upper Limits
  17. Integral GRB210829.17: Global MASTER-Net observations report
  18. Integral GRB210829.14: Global MASTER-Net observations report
  19. Fermi GRB 210827A: Global MASTER-Net observations report
  20. Fermi GRB 210827B: Global MASTER-Net observations report
  21. GRB 210827A: Swift-XRT observations
  22. GRB 210827A: Swift ToO observations
  23. GRB 210827A: Swift/BAT-GUANO detection and arcminute localization
  24. GRB 210820A: CAHA 2.2m Optical Detection
  25. GRB 210824A: Swift/UVOT Upper Limits
  26. GRB 210826A: Swift/UVOT Upper Limits
  27. GRB 210826A: Swift-XRT observations
  28. GRB 210822A: CAHA 2.2m observations
  29. Fermi GRB 210826A: Global MASTER-Net observations report
  30. GRB 210826A: Tiled Swift observations
  31. Swift GRB210825.29: Global MASTER-Net observations report
  32. GRB 210822A: TSHAO continued optical observation
  33. GRB 210822A: VLA detection
  34. GRB 210822A: Swift/UVOT Detection
  35. Swift GRB 210824A: Global MASTER-Net observations report
  36. Fermi GRB 210824A: Global MASTER-Net observations report
  37. GRB 210822A: GROND observations
  38. GRB 210822A: Detection by GRBAlpha
  39. GRB 210820A: GROND observations
  40. Konus-Wind detection of GRB 210822A
  41. Fermi trigger No 651306769: Global MASTER-Net observations report
  42. GRB 210820A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  43. GRB 210820A: Swift/UVOT Detection
  44. Fermi GRB 210822B: Global MASTER-Net observations report
  45. GRB 210822A: Nanshan/NEXT optical observations
  46. Swift GRB 210822A: Global MASTER-Net observations report
  47. GRB 210822A: RATIR Optical Detections
  48. GRB 210822A: KAIT Optical Afterglow Confirmation
  49. Fermi GRB 210821A: Global MASTER-Net observations report
  50. GRB 210820A: RATIR Optical Detections
  51. Swift GRB 210820A: Global MASTER-Net observations report
  52. Fermi trigger No 651110719: Global MASTER-Net observations report
  53. Swift GRB210818.68: Global MASTER-Net observations report
  54. Swift GRB 210818A: Global MASTER-Net observations report
  55. GRB 210726A: VLA radio afterglow detection
  56. Konus-Wind detection of GRB 210818A
  57. IceCube-210730A: not observable by Fermi-GBM
  58. IceCube-210811A: Upper limits from Fermi-GBM Observations
  59. Fermi trigger No 650687034: Global MASTER-Net observations report
  60. GRB 210812A is consistent with being a lensed GRB
  61. IceCube-210811A: No Candidate Counterparts from the Zwicky Transient Facility
  62. Fermi GRB 210813A: Global MASTER-Net observations report
  63. Fermi-LAT Gamma-ray Observations of IceCube-210811A
  64. GRB 210807A: continued Assy, AbAO and Mondy observations
  65. Fermi GRB 210812A: Global MASTER-Net observations report
  66. SGR 1935+2154: SPI INTEGRAL observations on 2021 August 5
  67. GRB 210730A: Tautenburg observations
  68. GRB 210807A: Tautenburg observations
  69. IceCube Alert 210811.09: Global MASTER-Net observations report
  70. GRB 210807A: Detection by GRBAlpha
  71. GRB 210802A: Further Swift/XRT observation and afterglow confirmation
  72. GRB 210807C: Swift/UVOT Upper Limits
  73. GRB 210807A: Swift/UVOT Detection
  74. GRB 210807A: correction to the GCN Circ. #30614 Assy optical observations
  75. GRB 210610B: Assy optical observations
  76. Swift GRB210807.74: Global MASTER-Net observations report
  77. Fermi GRB 210807C: Global MASTER-Net observations report
  78. Swift GRB210807.96: Global MASTER-Net observations report
  79. Fermi GRB 210807B: Global MASTER-Net observations report
  80. Swift GRB 210807A: Global MASTER-Net observations report
  81. Swift GRB210807.79: Global MASTER-Net observations report
  82. Swift GRB210807.78: Global MASTER-Net observations report
  83. Fermi trigger No 650046564: Global MASTER-Net observations report
  84. Fermi trigger No 649814537: Global MASTER-Net observations report
  85. Fermi trigger No 649684549: Global MASTER-Net observations report
  86. GRB 210802A: Swift-XRT afterglow detection
  87. GRB 210802A: Tiled Swift observations
  88. Fermi trigger No 649627691: Global MASTER-Net observations report
  89. GRB 210731A: continued GROND observations
  90. GRB 210731A: VLT/X-shooter redshift
  91. Fermi trigger No 649524889: Global MASTER-Net observations report
  92. Fermi trigger No 649519043: Global MASTER-Net observations report
  93. GRB 210731A: GROND observations
  94. GRB 210731A: Swift/UVOT Detection of an optical afterglow
  95. Swift GRB210731.62: Global MASTER-Net observations report
  96. GRB 210731A: MeerLICHT optical afterglow detection
  97. Swift GRB210731.93: Global MASTER-Net observations report
  98. Fermi-LAT Gamma-ray Observations of IceCube-210730A
  99. GRB 210730A: Campo Imperatore optical observations
  100. Swift GRB 210730A: Global MASTER-Net observations report

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