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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"

21114 results found.

  1. Swift GRB 210912A: Global MASTER-Net observations report
  2. GRB 210912A: BOOTES-5/JGT optical afterglow candidate
  3. GECAM observations of bursts from SGR J1935+2154 (2021-09-11T07 to 2021-09-12T08)
  4. Fermi trigger No 653093506: Global MASTER-Net observations report
  5. Fermi trigger No 653066776: Global MASTER-Net observations report
  6. Fermi trigger No 653084584: Global MASTER-Net observations report
  7. Fermi trigger No 653083551: Global MASTER-Net observations report
  8. Fermi trigger No 653079281: Global MASTER-Net observations report
  9. Fermi trigger No 653066130: Global MASTER-Net observations report
  10. Fermi trigger No 653072474: Global MASTER-Net observations report
  11. Fermi trigger No 653071808: Global MASTER-Net observations report
  12. Fermi trigger No 653054042: Global MASTER-Net observations report
  13. Fermi trigger No 653049776: Global MASTER-Net observations report
  14. Fermi trigger No 653022153: Global MASTER-Net observations report
  15. Fermi trigger No 653031163: Global MASTER-Net observations report
  16. Swift GRB210910.42: Global MASTER-Net observations report
  17. Fermi GBM observation of a bright flare in the direction of SGR 1935+2154
  18. Fermi trigger No 653010039: Global MASTER-Net observations report
  19. Fermi trigger No 652957973: Global MASTER-Net observations report
  20. Fermi trigger No 652944960: Global MASTER-Net observations report
  21. Fermi trigger No 652981861: Global MASTER-Net observations report
  22. GRB 210826A: further Swift-XRT observations
  23. GECAM observations of a series of bursts from SGR J1935+2154
  24. Fermi trigger No 652934203: Global MASTER-Net observations report
  25. Fermi trigger No 652927551: Global MASTER-Net observations report
  26. GRB 210619B: Maidanak and Assy optical observations, broken power law parametrization
  27. Fermi trigger No 652911693: Global MASTER-Net observations report
  28. Fermi trigger No 652906639: Global MASTER-Net observations report
  29. Fermi GRB 210909A: Global MASTER-Net observations report
  30. GRB 210905A: Swift/UVOT Upper Limits
  31. GRB 210905A: ATCA detection
  32. GRB 210905A: ALMA detection
  33. GRB 210905A, GROND observations
  34. Fermi trigger No 652585475: Global MASTER-Net observations report
  35. GRB 210610A: Maidanak and AbAO optical observations
  36. GRB 210905A: REM NIR afterglow detection
  37. GRB 210905A: VLT/X-shooter spectroscopic redshift
  38. GRB 210905A: Continued LCO Optical Observations
  39. GRB 210901A: Swift/UVOT Upper Limits
  40. Swift GRB 210905A: Global MASTER-Net observations report
  41. Fermi GRB 210904A: Global MASTER-Net observations report
  42. Swift GRB210903.59: Global MASTER-Net observations report
  43. Swift GRB210903.58: Global MASTER-Net observations report
  44. Swift GRB210903.58: Global MASTER-Net observations report
  45. Fermi GRB 210903A: Global MASTER-Net observations report
  46. Fermi GRB 210903B: Global MASTER-Net observations report
  47. GRB 210901A: GROND observations
  48. Swift GRB 210901A: Global MASTER-Net observations report
  49. GRB 210827A: further Swift-XRT observations
  50. GRB 210827A: Swift/UVOT Upper Limits
  51. Integral GRB210829.17: Global MASTER-Net observations report
  52. Integral GRB210829.14: Global MASTER-Net observations report
  53. Fermi GRB 210827A: Global MASTER-Net observations report
  54. Fermi GRB 210827B: Global MASTER-Net observations report
  55. GRB 210827A: Swift-XRT observations
  56. GRB 210827A: Swift ToO observations
  57. GRB 210827A: Swift/BAT-GUANO detection and arcminute localization
  58. GRB 210820A: CAHA 2.2m Optical Detection
  59. GRB 210824A: Swift/UVOT Upper Limits
  60. GRB 210826A: Swift/UVOT Upper Limits
  61. GRB 210826A: Swift-XRT observations
  62. GRB 210822A: CAHA 2.2m observations
  63. Fermi GRB 210826A: Global MASTER-Net observations report
  64. GRB 210826A: Tiled Swift observations
  65. Swift GRB210825.29: Global MASTER-Net observations report
  66. GRB 210822A: TSHAO continued optical observation
  67. GRB 210822A: VLA detection
  68. GRB 210822A: Swift/UVOT Detection
  69. Swift GRB 210824A: Global MASTER-Net observations report
  70. Fermi GRB 210824A: Global MASTER-Net observations report
  71. GRB 210822A: GROND observations
  72. GRB 210822A: Detection by GRBAlpha
  73. GRB 210820A: GROND observations
  74. Fermi trigger No 651306769: Global MASTER-Net observations report
  75. GRB 210820A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  76. GRB 210820A: Swift/UVOT Detection
  77. Fermi GRB 210822B: Global MASTER-Net observations report
  78. GRB 210822A: Nanshan/NEXT optical observations
  79. Swift GRB 210822A: Global MASTER-Net observations report
  80. GRB 210822A: KAIT Optical Afterglow Confirmation
  81. Fermi GRB 210821A: Global MASTER-Net observations report
  82. Swift GRB 210820A: Global MASTER-Net observations report
  83. Fermi trigger No 651110719: Global MASTER-Net observations report
  84. Swift GRB210818.68: Global MASTER-Net observations report
  85. Swift GRB 210818A: Global MASTER-Net observations report
  86. GRB 210726A: VLA radio afterglow detection
  87. IceCube-210730A: not observable by Fermi-GBM
  88. IceCube-210811A: Upper limits from Fermi-GBM Observations
  89. Fermi trigger No 650687034: Global MASTER-Net observations report
  90. GRB 210812A is consistent with being a lensed GRB
  91. IceCube-210811A: No Candidate Counterparts from the Zwicky Transient Facility
  92. Fermi GRB 210813A: Global MASTER-Net observations report
  93. Fermi-LAT Gamma-ray Observations of IceCube-210811A
  94. GRB 210807A: continued Assy, AbAO and Mondy observations
  95. Fermi GRB 210812A: Global MASTER-Net observations report
  96. SGR 1935+2154: SPI INTEGRAL observations on 2021 August 5
  97. GRB 210730A: Tautenburg observations
  98. GRB 210807A: Tautenburg observations
  99. IceCube Alert 210811.09: Global MASTER-Net observations report
  100. GRB 210807A: Detection by GRBAlpha

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