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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"

5559 results found.

  1. GRB 210731A: MeerLICHT optical afterglow detection
  2. GRB210731A: Enhanced Swift-XRT position
  3. GRB 210731A: Swift detection of a burst
  4. Trigger 1062273: Swift detection of 4U 1700-377
  5. Fermi trigger No 649390368: Global MASTER-Net observations report
  6. Fermi GBM Sub-Threshold Detection of GRB 210726A
  7. Fermi trigger No 649072251: Global MASTER-Net observations report
  8. GRB 210726A: Swift detection of a burst
  9. Fermi trigger No 648959581: Global MASTER-Net observations report
  10. GRB 210725A: Fermi GBM detection
  11. GRB 210725A: CALET Gamma-Ray Burst Monitor detection
  12. Fermi trigger No 648868114: Global MASTER-Net observations report
  13. GRB 210725A: Swift detection of a burst
  14. Swift GRB210725.16: Global MASTER-Net observations report
  15. GRB 210702A: ALMA detection of mm-band rebrightening
  16. Fermi trigger No 648602917: Global MASTER-Net observations report
  17. Fermi trigger No 647942198: Global MASTER-Net observations report
  18. Fermi trigger No 647805873: Global MASTER-Net observations report
  19. Fermi trigger No 647522278: Global MASTER-Net observations report
  20. Fermi GRB 210709A: Global MASTER-Net observations report
  21. GRB 210702A: ALMA detection
  22. GRB 210708B: Swift detection of a possible burst
  23. Fermi GBM Observations of SGR J1935+2154
  24. GRB 210704A: Fermi-LAT detection
  25. Fermi trigger No 647108723: Global MASTER-Net observations report
  26. Fermi trigger No 647120009: Global MASTER-Net observations report
  27. GRB 210702A: iTelescope optical afterglow observations
  28. Fermi GRB 210627B: Global MASTER-Net observations report
  29. Fermi GRB 210627A: Global MASTER-Net observations report
  30. Fermi trigger No 646322348: Global MASTER-Net observations report
  31. Fermi GRB 210626A: Global MASTER-Net observations report
  32. Fermi trigger No 646189108: Global MASTER-Net observations report
  33. GRB 210619B: Abbey Ridge Observatory optical afterglow observation
  34. Swift Trigger 1057131: detection of a burst from SGR Swift J1555.2-5402
  35. GRB 210619B: SAO RAS optical observations
  36. GRB 210621A: Fermi GBM Final Real-time Localization
  37. GRB 210619B: CAHA 2.2m photometric monitoring
  38. GRB 210619B: Liverpool Telescope r'-band observations
  39. GRB 210619B: Liverpool telescope imaging of a red afterglow
  40. Fermi trigger No 645857659: Global MASTER-Net observations report
  41. Swift GRB210619.99: Global MASTER-Net OT detection
  42. GRB 210618A: DDOTI upper limit for the optical afterglow
  43. GRB 210323B: Fermi GBM observation
  44. Fermi GRB 210615A: Global MASTER-Net observations report
  45. Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
  46. GRB 210610A: Fermi GBM observations
  47. GRB 210610B: iTelescope optical afterglow observations
  48. GRB 210610B: Further SAO RAS optical observations
  49. GRB 210610A: SAO RAS optical observations
  50. GRB 210610B: optical observations from Burke-Gaffney Observatory and Abbey Ridge Observatory
  51. GRB 210610B: optical photometry of afterglow at INASAN/Simeiz
  52. Swift-BAT Trigger 1055000: Swift detection of an outburst from 4U 1543-47
  53. GRB 210606A: Fermi GBM detection
  54. Konus-Wind detection of GRB 210610A
  55. GRB 210610B: SAO RAS optical observations
  56. Fermi trigger No 645047470: Global MASTER-Net observations report
  57. GRB 210610A: Swift detection of a burst with an optical counterpart
  58. Fermi-LAT Gamma-ray Observations of IceCube-210608A
  59. IceCube-210608A: IceCube observation of a high-energy neutrino candidate track-like event
  60. IceCube Alert 210608.15: Global MASTER-Net observations report
  61. Konus-Wind detection of GRB 210602A
  62. GRB 210606B: AGILE detection
  63. GRB 210606A: Swift/BAT-GUANO detection and arcminute localization
  64. GRB 210606A: Fermi GBM Final Real-time Localization
  65. Initial results of a NICER X-ray monitoring of the magnetar, Swift J1555.2-5402
  66. SGR J1555.2-5402: Swift-BAT refined analysis
  67. Fermi trigger No 644449593: Global MASTER-Net observations report
  68. Swift J1555.2-5402: Swift XRT refined analysis of the new SGR
  69. NICER discovery of 3.86 s pulsations from a new magnetar: SGR J1555.2-5402
  70. Swift Detection of probable new Swift SGR J1555.2-5402
  71. MAXI GRB210602.50: Global MASTER-Net observations report
  72. Swift GRB210603.41: Global MASTER-Net observations report
  73. Fermi trigger No 644359567: Global MASTER-Net observations report
  74. GRB 210602A: MAXI/GSC detection
  75. GRB 210529B: DDOTI Upper Limits on the Afterglow
  76. Fermi GRB 210529B: Global MASTER-Net observations report
  77. GRB 210528A: Fermi GBM detection
  78. GRB 210528A: AstroSat CZTI detection
  79. GRB 210528A: BALROG localization (Fermi Trigger 643903431 / GRB 210528586)
  80. GRB 210528A: Fermi GBM Final Real-time Localization
  81. Fermi GRB 210524B: DDOTI Upper Limits on the Afterglow
  82. Fermi GRB 210519A: Global MASTER-Net observations report
  83. IPN triangulation of GRB 210518A
  84. Fermi trigger No 643065622: Global MASTER-Net observations report
  85. GRB 210518.889: DDOTI Upper Limits on the Afterglow
  86. Fermi trigger No 642991619: Global MASTER-Net observations report
  87. Fermi GRB 210516A: Global MASTER-Net observations report
  88. Fermi GRB 210515B: Global MASTER-Net observations report
  89. Fermi GRB 210515A: Global MASTER-Net observations report
  90. Fermi GRB 210511A: Global MASTER-Net observations report
  91. Fermi GRB 210510A: DDOTI Upper Limits on the Afterglow
  92. Fermi GRB 210510A: Global MASTER-Net observations report
  93. Swift trigger 1047857 is 4U 1700-377
  94. Fermi-LAT Gamma-ray Observations of IceCube-210503A and detection of a new gamma-ray source, Fermi J0931.9+3633
  95. IceCube-210503A: IceCube observation of a high-energy neutrino candidate event
  96. DDOTI Observations of ZTF21aayokph (AT2021lfa)
  97. Swift GRB210504.58: Global MASTER-Net observations report
  98. Fermi GRB 210503A: Global MASTER-Net observations report
  99. Swift GRB210502.74: Global MASTER-Net observations report
  100. Swift Detection of MAXI J1803-298 including an optical counterpart

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