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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"

21129 results found.

  1. GRB 210610B: AbAO optical observations
  2. Fermi GRB 210615A: Global MASTER-Net observations report
  3. GRB 210610B: REM optical/NIR observations of the afterglow
  4. Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
  5. Swift ToO Observations of HAWC transient J0020+3108
  6. GRB 210605B: Swift-XRT afterglow detection
  7. GRB 210610A: Fermi GBM observations
  8. GRB 210610A: CAHA 2.2m Second Epoch
  9. GRB 210610B: iTelescope optical afterglow observations
  10. GRB 210610B: Further SAO RAS optical observations
  11. GRB 210610A: SAO RAS optical observations
  12. GRB 210610B: optical observations from Burke-Gaffney Observatory and Abbey Ridge Observatory
  13. GRB 210610B: Continued KAIT Optical Detection
  14. Swift GRB210612.54: Global MASTER-Net observations report
  15. GRB 210610B: VLA detection
  16. GRB 210610B: ALMA detection
  17. GRB 210610B: CrAO/ZTSH optical observations and light curve
  18. GRB 210610A: CrAO/ZTSH optical observations
  19. GRB 210610B: CrAO/ZTSH optical observations (correction to the GCN circ. 30212)
  20. GRB 210610A: CrAO/ZTSH optical observations
  21. GRB 210610A: CAHA 2.2m observations and light-curve behavior
  22. GRB 210610B: Zwicky Transient Facility afterglow detection
  23. GRB 210610B: optical afterglow observations
  24. GRB 210610B: Spectroscopy and redshift confirmation with the Himalayan Chandra Telescope
  25. GRB 210610A: Spectroscopy and redshift confirmation with the Himalayan Chandra Telescope
  26. GRB 210610B: University of Siena Observatory optical photometry of the afterglow
  27. GRB 210610B: GOTO confirmation of afterglow detection
  28. GRB 210610B: RATIR Optical and NIR Observations
  29. GRB 210610B: SAO RAS optical observations
  30. GRB 210610A: 1.5m OSN optical observation
  31. HAWC Transient Monitoring Alert: Significant Spot after 3 transits
  32. GRB 210610B: NOT optical observations and tentative redshift
  33. GRB 210610B: iTelescope optical afterglow observations
  34. GRB210610B: MeerLICHT multi-colour photometry
  35. Fermi trigger No 645047470: Global MASTER-Net observations report
  36. GRB 210610B: CrAO/ZTSh optical afterglow photometry
  37. GRB 210610B: BOOTES-2/TELMA optical observation
  38. Swift GRB 210610B: Global MASTER-Net observations report
  39. GRB 210610B: CrAO/ZTSh optical observations
  40. GRB 210606A: Swift-XRT afterglow detection
  41. GRB210610A: MeerLICHT multi-colour photometry
  42. Swift GRB 210610A: Global MASTER-Net observations report
  43. Swift GRB 210610A: MASTER optical counterpart observation
  44. GRB 210610A: Xinglong-2.16m optical afterglow observations
  45. Fermi-LAT Gamma-ray Observations of IceCube-210608A
  46. IceCube-210608A: not observable by Fermi-GBM
  47. IceCube Alert 210608.15: Global MASTER-Net observations report
  48. MAXI GRB210607.82: Global MASTER-Net observations report
  49. Fermi trigger No 644793834: Global MASTER-Net observations report
  50. GRB 210605B: Swift-XRT observations
  51. Fermi trigger No 644712030: Global MASTER-Net observations report
  52. GRB 210606A: Swift ToO observations
  53. GRB 210606A: Swift/BAT-GUANO detection and arcminute localization
  54. GRB 210605B: Swift ToO observations
  55. Fermi GRB 210606A: Global MASTER-Net observations report
  56. Fermi GRB 210605A: Global MASTER-Net observations report
  57. Initial results of a NICER X-ray monitoring of the magnetar, Swift J1555.2-5402
  58. Fermi trigger No 644449593: Global MASTER-Net observations report
  59. MAXI GRB210602.50: Global MASTER-Net observations report
  60. Swift GRB210603.41: Global MASTER-Net observations report
  61. Fermi trigger No 644359567: Global MASTER-Net observations report
  62. Fermi GRB 210601A: Global MASTER-Net observations report
  63. GRB210529B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 644025222)
  64. Fermi trigger No 644155206: Global MASTER-Net observations report
  65. Fermi GRB 210529A: Global MASTER-Net observations report
  66. Fermi GRB 210529B: Global MASTER-Net observations report
  67. MAXI GRB210528.95: Global MASTER-Net observations report
  68. Fermi GRB 210528A: Global MASTER-Net observations report
  69. GRB 210527A: Swift/UVOT Observations
  70. Swift GRB 210527A: Global MASTER-Net observations report
  71. GRB 210527A: RATIR Optical and NIR Observations
  72. GRB 210527A: Swift-XRT observations
  73. GRB 210306A: LBT observations of the likely host galaxy
  74. ZTF21aayokph (AT2021lfa): LBT optical observations
  75. Fermi trigger No 643548039: Global MASTER-Net observations report
  76. Fermi GRB 210524A: Global MASTER-Net observations report
  77. GRB 210520A: Swift-XRT observations
  78. MAXI GRB210521.54: Global MASTER-Net observations report
  79. GRB210413B: further Swift-XRT observations
  80. ZTF21aayokph (AT2021lfa): continued Assy optical observations
  81. GRB 210520A: Tiled Swift observations
  82. Fermi GRB 210520A: Global MASTER-Net observations report
  83. Fermi GRB 210519A: Global MASTER-Net observations report
  84. IceCube Alert 210519.86: Global MASTER-Net observations report
  85. Fermi trigger No 643065622: Global MASTER-Net observations report
  86. Fermi GRB 210518A: Global MASTER-Net observations report
  87. Fermi trigger No 642991619: Global MASTER-Net observations report
  88. Fermi-LAT Gamma-ray Observations of IceCube-210516A
  89. IceCube Alert 210515.01: Global MASTER-Net observations report
  90. GRB 210517A: Swift/UVOT Upper Limits
  91. GRB 210515C: Swift/UVOT Upper Limits
  92. Swift GRB 210517A: Global MASTER-Net observations report
  93. Fermi GRB 210516A: Global MASTER-Net observations report
  94. IceCube Alert 210516.61: Global MASTER-Net observations report
  95. GRB 210514A: Swift/UVOT Upper Limits
  96. Swift GRB210515.83: Global MASTER-Net observations report
  97. Fermi GRB 210515B: Global MASTER-Net observations report
  98. GRB 210514A: Swift-BAT refined analysis
  99. Fermi GRB 210515A: Global MASTER-Net observations report
  100. Swift GRB210514.71: Global MASTER-Net observations report

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