Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. See news and announcements

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. Fermi trigger No 653049776: Global MASTER-Net observations report
  2. Fermi trigger No 653022153: Global MASTER-Net observations report
  3. Fermi trigger No 653031163: Global MASTER-Net observations report
  4. Swift GRB210910.42: Global MASTER-Net observations report
  5. Fermi GBM observation of a bright flare in the direction of SGR 1935+2154
  6. Fermi trigger No 653010039: Global MASTER-Net observations report
  7. Fermi trigger No 652957973: Global MASTER-Net observations report
  8. Fermi trigger No 652944960: Global MASTER-Net observations report
  9. Fermi trigger No 652981861: Global MASTER-Net observations report
  10. GRB 210826A: further Swift-XRT observations
  11. GECAM observations of a series of bursts from SGR J1935+2154
  12. Fermi trigger No 652934203: Global MASTER-Net observations report
  13. Fermi trigger No 652927551: Global MASTER-Net observations report
  14. GRB 210619B: Maidanak and Assy optical observations, broken power law parametrization
  15. Fermi trigger No 652911693: Global MASTER-Net observations report
  16. Fermi trigger No 652906639: Global MASTER-Net observations report
  17. Fermi GRB 210909A: Global MASTER-Net observations report
  18. GRB 210905A: Swift/UVOT Upper Limits
  19. GRB 210905A: ATCA detection
  20. GRB 210905A: ALMA detection
  21. GRB 210905A, GROND observations
  22. Fermi trigger No 652585475: Global MASTER-Net observations report
  23. GRB 210610A: Maidanak and AbAO optical observations
  24. GRB 210905A: REM NIR afterglow detection
  25. GRB 210905A: VLT/X-shooter spectroscopic redshift
  26. GRB 210905A: Continued LCO Optical Observations
  27. GRB 210901A: Swift/UVOT Upper Limits
  28. Swift GRB 210905A: Global MASTER-Net observations report
  29. Fermi GRB 210904A: Global MASTER-Net observations report
  30. Swift GRB210903.59: Global MASTER-Net observations report
  31. Swift GRB210903.58: Global MASTER-Net observations report
  32. Swift GRB210903.58: Global MASTER-Net observations report
  33. Fermi GRB 210903A: Global MASTER-Net observations report
  34. Fermi GRB 210903B: Global MASTER-Net observations report
  35. GRB 210901A: GROND observations
  36. Swift GRB 210901A: Global MASTER-Net observations report
  37. GRB 210827A: further Swift-XRT observations
  38. GRB 210827A: Swift/UVOT Upper Limits
  39. Integral GRB210829.17: Global MASTER-Net observations report
  40. Integral GRB210829.14: Global MASTER-Net observations report
  41. Fermi GRB 210827A: Global MASTER-Net observations report
  42. Fermi GRB 210827B: Global MASTER-Net observations report
  43. GRB 210827A: Swift-XRT observations
  44. GRB 210827A: Swift ToO observations
  45. GRB 210827A: Swift/BAT-GUANO detection and arcminute localization
  46. GRB 210820A: CAHA 2.2m Optical Detection
  47. GRB 210824A: Swift/UVOT Upper Limits
  48. GRB 210826A: Swift/UVOT Upper Limits
  49. GRB 210826A: Swift-XRT observations
  50. GRB 210822A: CAHA 2.2m observations
  51. Fermi GRB 210826A: Global MASTER-Net observations report
  52. GRB 210826A: Tiled Swift observations
  53. Swift GRB210825.29: Global MASTER-Net observations report
  54. GRB 210822A: TSHAO continued optical observation
  55. GRB 210822A: VLA detection
  56. GRB 210822A: Swift/UVOT Detection
  57. Swift GRB 210824A: Global MASTER-Net observations report
  58. Fermi GRB 210824A: Global MASTER-Net observations report
  59. GRB 210822A: GROND observations
  60. GRB 210822A: Detection by GRBAlpha
  61. GRB 210820A: GROND observations
  62. Konus-Wind detection of GRB 210822A
  63. Fermi trigger No 651306769: Global MASTER-Net observations report
  64. GRB 210820A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  65. GRB 210820A: Swift/UVOT Detection
  66. Fermi GRB 210822B: Global MASTER-Net observations report
  67. GRB 210822A: Nanshan/NEXT optical observations
  68. Swift GRB 210822A: Global MASTER-Net observations report
  69. GRB 210822A: RATIR Optical Detections
  70. GRB 210822A: KAIT Optical Afterglow Confirmation
  71. Fermi GRB 210821A: Global MASTER-Net observations report
  72. GRB 210820A: RATIR Optical Detections
  73. Swift GRB 210820A: Global MASTER-Net observations report
  74. Fermi trigger No 651110719: Global MASTER-Net observations report
  75. Swift GRB210818.68: Global MASTER-Net observations report
  76. Swift GRB 210818A: Global MASTER-Net observations report
  77. GRB 210726A: VLA radio afterglow detection
  78. Konus-Wind detection of GRB 210818A
  79. IceCube-210730A: not observable by Fermi-GBM
  80. IceCube-210811A: Upper limits from Fermi-GBM Observations
  81. Fermi trigger No 650687034: Global MASTER-Net observations report
  82. GRB 210812A is consistent with being a lensed GRB
  83. IceCube-210811A: No Candidate Counterparts from the Zwicky Transient Facility
  84. Fermi GRB 210813A: Global MASTER-Net observations report
  85. Fermi-LAT Gamma-ray Observations of IceCube-210811A
  86. GRB 210807A: continued Assy, AbAO and Mondy observations
  87. Fermi GRB 210812A: Global MASTER-Net observations report
  88. SGR 1935+2154: SPI INTEGRAL observations on 2021 August 5
  89. GRB 210730A: Tautenburg observations
  90. GRB 210807A: Tautenburg observations
  91. IceCube Alert 210811.09: Global MASTER-Net observations report
  92. GRB 210807A: Detection by GRBAlpha
  93. GRB 210802A: Further Swift/XRT observation and afterglow confirmation
  94. GRB 210807C: Swift/UVOT Upper Limits
  95. GRB 210807A: Swift/UVOT Detection
  96. GRB 210807A: correction to the GCN Circ. #30614 Assy optical observations
  97. GRB 210610B: Assy optical observations
  98. Swift GRB210807.74: Global MASTER-Net observations report
  99. Fermi GRB 210807C: Global MASTER-Net observations report
  100. Swift GRB210807.96: Global MASTER-Net observations report

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov