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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"

22208 results found.

  1. GRB 220430A: GRANDMA observations
  2. GRB 220430A: Mondy and AbAO optical upper limits
  3. GRB 220430A: MeerLICHT optical upper limits
  4. GRB 220430A: Swift detection of a burst or Swift J0630.4+0932
  5. GRB 220426A: Swift-XRT and UVOT observations
  6. GRB 220426A: Tiled Swift observations
  7. Konus-Wind detection of GRB 220426A
  8. GRB 220426C: Swift/BAT-GUANO detection outside the coded FOV (short)
  9. Fermi GRB 220426A: Global MASTER-Net observations report
  10. GRB 220426A: Swift/BAT-GUANO detection outside the coded FOV
  11. Fermi-LAT Gamma-ray Observations of IceCube-220425A
  12. Fermi GRB 220426B: Global MASTER-Net observations report
  13. IceCube-220425A: MASTER: flaring blazar TXS 1742-078 as the possible neutrino source candidate
  14. Fermi-LAT Gamma-ray Observations of IceCube-220424A
  15. IceCube Alert 220425.11: Global MASTER-Net observations report
  16. Fermi trigger No 672492774: Global MASTER-Net observations report
  17. GRB 220423A: Swift/BAT-GUANO detection outside the coded FOV
  18. IceCube Alert 220424.05: Global MASTER-Net observations report
  19. Fermi trigger No 672374264: Global MASTER-Net observations report
  20. Fermi-LAT Gamma-ray Observations of IceCube-220421A
  21. GRB 220421A: Swift/BAT-GUANO detection outside the coded FOV
  22. Fermi trigger No 672221879: Global MASTER-Net observations report
  23. GRB 220418B: Swift-XRT observations
  24. IceCube Alert 220421.22: Global MASTER-Net observations report
  25. Fermi trigger No 672093919: Global MASTER-Net observations report
  26. GRB 220420A: Swift/BAT-GUANO detection outside the coded FOV
  27. GRB 220403C: Further Swift-XRT observations
  28. GRB 220418B: Swift ToO observations
  29. GRB 220418B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  30. GRB 220417A: Swift/BAT-GUANO detection outside the coded FOV
  31. GRB 220412B: Swift/UVOT Upper Limits
  32. Fermi GRB 220418A: Global MASTER-Net observations report
  33. Fermi GRB 220417A: Global MASTER-Net observations report
  34. Fermi trigger No 671729344: Global MASTER-Net observations report
  35. Konus-Wind detection of GRB 220403C
  36. Konus-Wind detection of GRB 220408B
  37. GRB 220412B: TNG optical observations
  38. GRB 220412A: GRANDMA observations
  39. GRB 220412A: Continued RATIR Observations and Steepening of the Light Curve
  40. GRB 220412A: RATIR Observations of the Fading Afterglow
  41. GRB 220412B: Swift-XRT observations
  42. Swift GRB 220412B: Global MASTER-Net observations report
  43. GRB 220408A: HCT optical upper limit
  44. GRB 220412B: Swift detection of a short burst
  45. GRB 220412A: Swift/UVOT Upper Limits
  46. GRB 220408A: GRANDMA observations
  47. GRB 220403B: GRANDMA observations
  48. GRB 220412A: RATIR Afterglow Candidate
  49. Swift GRB220412.28: Global MASTER-Net observations report
  50. GRB 220403B: Swift/UVOT Detection
  51. GRB 220408A: Lowell Discovery Telescope Optical Observations
  52. Fermi GRB 220411A: Global MASTER-Net observations report
  53. GRB 220408A: RATIR Optical and NIR Observations
  54. GRB 220403B: 1.3m DFOT Optical upper limit
  55. GRB 220408A: 1.3m DFOT Optical upper limit
  56. GRB 220403C: Swift-XRT observations
  57. GRB 220408A: NOT optical observations and archival detection
  58. GRB 220403C: Swift ToO observations
  59. GRB 220408A: BOOTES-5/JGT optical afterglow detection
  60. Fermi GRB 220408B: Global MASTER-Net observations report
  61. GRB 220408A: Swift/UVOT Detection
  62. GRB 220408A: Xinglong-2.16m optical upper limit
  63. GRB 220408A: KAIT Optical Observations
  64. Fermi GRB 220408A: Global MASTER-Net observations report
  65. GRB 220408A: Swift detection of a burst with an optical counterpart, possibly associated with M51
  66. ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, SAO RAS, CrAO)
  67. Fermi-LAT Gamma-ray Observations of IceCube-220405B
  68. IceCube-220405A: No Candidate Counterparts from the Zwicky Transient Facility
  69. IceCube-220405B: No Candidate Counterparts from the Zwicky Transient Facility
  70. GRB 220403B: 1.5m OSN optical observation
  71. IceCube Alert 220405.93: Global MASTER-Net observations report
  72. GRB 220403B: Kitab optical observations
  73. Fermi-LAT Gamma-ray Observations of IceCube-220405A
  74. IceCube Alert 220405.21: Global MASTER-Net observations report
  75. GRB 220403B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  76. GRB 220403B: LBT observations
  77. Swift GRB 220403B: Global MASTER-Net observations report
  78. GRB 220403C (or A): Swift/BAT-GUANO detection outside the coded FOV
  79. GRB 220403B: Nanshan/NEXT optical afterglow power-law decay
  80. GRB 220403A: Tautenburg observations
  81. GRB 220403B: optical detection by D50
  82. Fermi GRB 220403A: Global MASTER-Net observations report
  83. GRB 220401A: Swift/BAT-GUANO detection outside the coded FOV
  84. Swift GRB220402.16: Global MASTER-Net observations report
  85. Fermi GRB 220401B: Global MASTER-Net observations report
  86. Fermi trigger No 670501065: Global MASTER-Net observations report
  87. Fermi GRB 220330A: Global MASTER-Net observations report
  88. ZTF22aaajecp/AT2022cmc: 1.3m DFOT Optical observations
  89. GRB 220325A: GRANDMA observations
  90. Konus-Wind observation of GRB 220320A
  91. GRB 220325A: Swift/UVOT Upper Limits
  92. ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, TSHAO, AbAO)
  93. GRB 220325A: Tautenburg observations
  94. GRB 220325A: 1.3m DFOT Optical upper limit
  95. GRB 220325A: MASTER Global Robotic Net optical observations
  96. GRB 220319A: GRANDMA observations
  97. GRB220319A: Optical observations from NOT
  98. GRB 220319A: MASTER Global Robotic Net optical observations
  99. Fermi-LAT Gamma-ray Observations of IceCube-220317A
  100. GRB 220317A: Swift/BAT-GUANO detection outside the coded FOV

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