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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"

22237 results found.

  1. Swift-BAT Trigger 1055000: Swift detection of an outburst from 4U 1543-47
  2. GRB 210610B: VLA detection
  3. GRB 210610B: ALMA detection
  4. GRB 210610B: CrAO/ZTSH optical observations and light curve
  5. GRB 210610A: CrAO/ZTSH optical observations
  6. GRB 210610B: CrAO/ZTSH optical observations (correction to the GCN circ. 30212)
  7. GRB 210610A: CrAO/ZTSH optical observations
  8. GRB 210610A: CAHA 2.2m observations and light-curve behavior
  9. GRB 210610B: Zwicky Transient Facility afterglow detection
  10. GRB 210610B: optical afterglow observations
  11. GRB 210610B: Spectroscopy and redshift confirmation with the Himalayan Chandra Telescope
  12. GRB 210610A: Spectroscopy and redshift confirmation with the Himalayan Chandra Telescope
  13. GRB 210610B: University of Siena Observatory optical photometry of the afterglow
  14. Konus-Wind detection of GRB 210610B
  15. GRB 210610B: GOTO confirmation of afterglow detection
  16. GRB 210610A: RATIR Optical and NIR Detection
  17. GRB 210610B: RATIR Optical and NIR Observations
  18. GRB 210610B: SAO RAS optical observations
  19. GRB 210610A: 1.5m OSN optical observation
  20. HAWC Transient Monitoring Alert: Significant Spot after 3 transits
  21. GRB 210610B: NOT optical observations and tentative redshift
  22. GRB 210610B: iTelescope optical afterglow observations
  23. GRB210610B: MeerLICHT multi-colour photometry
  24. Fermi trigger No 645047470: Global MASTER-Net observations report
  25. GRB 210610B: CrAO/ZTSh optical afterglow photometry
  26. GRB 210610B: BOOTES-2/TELMA optical observation
  27. Swift GRB 210610B: Global MASTER-Net observations report
  28. GRB 210610B: CrAO/ZTSh optical observations
  29. GRB 210606A: Swift-XRT afterglow detection
  30. GRB210610A: MeerLICHT multi-colour photometry
  31. Swift GRB 210610A: Global MASTER-Net observations report
  32. GRB 210610A: Xinglong-2.16m optical afterglow observations
  33. Konus-Wind detection of GRB 210606B
  34. Fermi-LAT Gamma-ray Observations of IceCube-210608A
  35. IceCube-210608A: not observable by Fermi-GBM
  36. IceCube Alert 210608.15: Global MASTER-Net observations report
  37. MAXI GRB210607.82: Global MASTER-Net observations report
  38. Fermi trigger No 644793834: Global MASTER-Net observations report
  39. GRB 210605B: Swift-XRT observations
  40. Fermi trigger No 644712030: Global MASTER-Net observations report
  41. GRB 210606A: Swift ToO observations
  42. GRB 210606A: Swift/BAT-GUANO detection and arcminute localization
  43. GRB 210605B: Swift ToO observations
  44. Fermi GRB 210606A: Global MASTER-Net observations report
  45. GRB 210605B: Swift/BAT-GUANO detection and arcminute localization
  46. Fermi GRB 210605A: Global MASTER-Net observations report
  47. Initial results of a NICER X-ray monitoring of the magnetar, Swift J1555.2-5402
  48. Fermi trigger No 644449593: Global MASTER-Net observations report
  49. Swift Detection of probable new Swift SGR J1555.2-5402
  50. MAXI GRB210602.50: Global MASTER-Net observations report
  51. Swift GRB210603.41: Global MASTER-Net observations report
  52. Fermi trigger No 644359567: Global MASTER-Net observations report
  53. Fermi GRB 210601A: Global MASTER-Net observations report
  54. GRB210529B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 644025222)
  55. Fermi trigger No 644155206: Global MASTER-Net observations report
  56. Fermi GRB 210529A: Global MASTER-Net observations report
  57. Fermi GRB 210529B: Global MASTER-Net observations report
  58. MAXI GRB210528.95: Global MASTER-Net observations report
  59. Fermi GRB 210528A: Global MASTER-Net observations report
  60. GRB 210527A: Swift/UVOT Observations
  61. Swift GRB 210527A: Global MASTER-Net observations report
  62. GRB 210527A: RATIR Optical and NIR Observations
  63. GRB 210527A: Swift-XRT observations
  64. GRB 210306A: LBT observations of the likely host galaxy
  65. ZTF21aayokph (AT2021lfa): LBT optical observations
  66. Fermi trigger No 643548039: Global MASTER-Net observations report
  67. Fermi GRB 210524A: Global MASTER-Net observations report
  68. GRB 210520A: Swift-XRT observations
  69. MAXI GRB210521.54: Global MASTER-Net observations report
  70. GRB210413B: further Swift-XRT observations
  71. ZTF21aayokph (AT2021lfa): continued Assy optical observations
  72. GRB 210520A: Tiled Swift observations
  73. Fermi GRB 210520A: Global MASTER-Net observations report
  74. Fermi GRB 210519A: Global MASTER-Net observations report
  75. IceCube Alert 210519.86: Global MASTER-Net observations report
  76. Fermi trigger No 643065622: Global MASTER-Net observations report
  77. Fermi GRB 210518A: Global MASTER-Net observations report
  78. Konus-Wind detection of GRB 210514A
  79. Fermi trigger No 642991619: Global MASTER-Net observations report
  80. Fermi-LAT Gamma-ray Observations of IceCube-210516A
  81. IceCube Alert 210515.01: Global MASTER-Net observations report
  82. GRB 210517A: Swift-BAT refined analysis
  83. GRB 210517A: Swift/UVOT Upper Limits
  84. GRB 210515C: Swift/UVOT Upper Limits
  85. GRB 210517A: VLT/X-shooter optical afterglow and redshift
  86. Swift GRB 210517A: Global MASTER-Net observations report
  87. Fermi GRB 210516A: Global MASTER-Net observations report
  88. IceCube Alert 210516.61: Global MASTER-Net observations report
  89. GRB 210514A: Swift/UVOT Upper Limits
  90. Swift GRB210515.83: Global MASTER-Net observations report
  91. Fermi GRB 210515B: Global MASTER-Net observations report
  92. Fermi GRB 210515A: Global MASTER-Net observations report
  93. Swift GRB210514.71: Global MASTER-Net observations report
  94. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEM-210515A and 210515B
  95. GRB210510A: Optical afterglow candidate from the Zwicky Transient Facility
  96. Fermi trigger No 642538568: Global MASTER-Net observations report
  97. IceCube-210510A: not observable by Fermi-GBM
  98. Short GRB 210323A: likely host galaxy detection
  99. IceCube-210510A: No candidate counterparts from the Zwicky Transient Facility
  100. Fermi-LAT Gamma-ray Observations of IceCube-210510A

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