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"

24613 results found.

  1. GRB 211229A: Swift/BAT-GUANO arcminute localization
  2. GRB 211229A: GECAM detection
  3. Fermi GRB 211229A: Global MASTER-Net observations report
  4. GRB 211229A: Fermi GBM Final Real-time Localization
  5. GRB 211227A: Swift-BAT refined analysis
  6. Konus-Wind detection of the intermediate flare from SGR 1935+2154
  7. GRB 211227A: A possible short GRB with extended emission at z = 0.228?
  8. GRB 211227A: LCO Optical Observations
  9. Swift GRB211227.98: Global MASTER-Net observations report
  10. GRB 211226A: Swift/BAT-GUANO detection outside the coded FOV
  11. GRB 211225B: Swift-BAT refined analysis
  12. Fermi trigger No 662216114: Global MASTER-Net observations report
  13. GRB 211225A: MITSuME Akeno optical upper limits
  14. Swift GRB 211225B: Global MASTER-Net observations report
  15. Fermi GRB 211225C: Global MASTER-Net observations report
  16. GRB 211225C: Fermi GBM Final Real-time Localization
  17. GRB 211225B: Swift detection of a burst
  18. MAXI GRB211225.14: Global MASTER-Net observations report
  19. Fermi trigger No 662084433: Global MASTER-Net observations report
  20. GRB 211224A: Fermi GBM Final Real-time Localization
  21. GRB 211211A: observations with the 3.6m Devasthal Optical Telescope
  22. Fermi trigger No 662010159: Global MASTER-Net observations report
  23. GRB 211223C: Swift-BAT refined analysis
  24. Swift GRB 211223C: Global MASTER-Net observations report
  25. Fermi GRB 211223B: Global MASTER-Net observations report
  26. GRB 211221A: Swift-BAT refined analysis
  27. GRB 211223C: Swift detection of a burst
  28. GRB 211223B: Fermi GBM Final Real-time Localization
  29. GRB 211223A: GECAM detection
  30. GRB 211221A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  31. Fermi GRB 211222A: Global MASTER-Net observations report
  32. GRB 211222A: Fermi GBM Final Real-time Localization
  33. GRB 211218A: MITSuME Akeno optical upper limits
  34. GRB 211221A: MeerLICHT optical limits
  35. Swift GRB 211221A: Global MASTER-Net observations report
  36. IceCube-211216B: No significant detection in HAWC
  37. IceCube-211216A: No significant detection in HAWC
  38. GRB 211219A: Swift/BAT-GUANO detection outside the coded FOV
  39. Fermi GRB 211219B: Global MASTER-Net observations report
  40. GRB 211219B: Fermi GBM Final Real-time Localization
  41. Fermi GRB 211219A: Global MASTER-Net observations report
  42. GRB 211219A: Fermi GBM Final Real-time Localization
  43. GRB 211211A: MMT/MMIRS Observations Indicate Fading of K-band Source
  44. GRB 211216A: Fermi GBM observation
  45. IceCube-211216B: No neutrino counterpart candidates in ANTARES search
  46. MAXI GRB211218.04: Global MASTER-Net observations report
  47. Fermi-LAT Gamma-ray Observations of IceCube-211216B
  48. Fermi-LAT Gamma-ray Observations of IceCube-211216A
  49. IceCube-211216B: Upper limits from Fermi-GBM Observations
  50. IceCube-211216A: Upper limits from Fermi-GBM Observations
  51. IceCube-211216A: Upper limits from a search for additional neutrino events in IceCube
  52. Fermi trigger No 661417475: Global MASTER-Net observations report
  53. IceCube-211216A: No neutrino counterpart candidates in ANTARES search
  54. GRB 211217A: GECAM detection
  55. GRB 211216A: Swift/BAT-GUANO detection outside the coded FOV
  56. IceCube-211216B - IceCube observation of a high-energy neutrino candidate track-like event
  57. IceCube Alert 211216.99: Global MASTER-Net observations report
  58. Fermi GRB 211216B: Global MASTER-Net observations report
  59. GRB 211216B: GECAM detection
  60. IceCube Alert 211216.30: Global MASTER-Net observations report
  61. GRB 211216B: Fermi GBM Final Real-time Localization
  62. IceCube-211216A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  63. GRB 211211A: TNG NIR observations
  64. IceCube-211216A - IceCube observation of a high-energy neutrino candidate track-like event
  65. GRB 211216A: GECAM detection
  66. GRB 211216A: BALROG localization (Fermi Trigger 661329957 / GRB 211216282)
  67. Fermi GRB 211216A: Global MASTER-Net observations report
  68. GRB 211216A: Fermi GBM Final Real-time Localization
  69. Chandra observation of GW170817 at ~1575 days since merger (all epochs)
  70. GRB 211211A: redshift estimation and SPI-ACS/INTEGRAL detection
  71. IceCube-211208A: No neutrino counterpart detected with ANTARES
  72. Fermi GRB 211212A: Global MASTER-Net observations report
  73. GRB 211211A: NOT optical spectroscopy
  74. GRB 211211B: GECAM detection
  75. Fermi GRB 211212B: Global MASTER-Net observations report
  76. GRB 211211A: MITSuME Akeno optical observation
  77. Swift GRB 211211A: Global MASTER-Net observations report
  78. GRB 211212B: Fermi GBM Final Real-time Localization
  79. GRB 211211A: LCO Optical Observations
  80. GRB 211211A: Nanshan/NEXT optical observations
  81. GRB 211212A: Fermi GBM Final Real-time Localization
  82. GRB 211211A: Fermi GBM observation
  83. GRB 211211A: Swift-BAT refined analysis
  84. Fermi GRB 211211B: Global MASTER-Net observations report
  85. GRB 211211B: Fermi GBM Final Real-time Localization
  86. Fermi GRB 211211A: Global MASTER-Net observations report
  87. GRB 211211A: KAIT Optical Afterglow Candidate
  88. GRB 211211A: Swift detection of a bright burst
  89. GRB 211211A: Fermi GBM Final Real-time Localization
  90. Fermi trigger No 660868196: Global MASTER-Net observations report
  91. IceCube-211208A: No significant detection in HAWC
  92. AMON NuEm-211020A: No neutrino counterpart detected with ANTARES
  93. Fermi trigger No 660736561: Global MASTER-Net observations report
  94. GRB 211130A: MeerLICHT identification of possible afterglow candidate
  95. IceCube-211208A: Upper limits from a search for additional neutrino events in IceCube
  96. Fermi-LAT Gamma-ray Observations of IceCube-211208A
  97. IceCube-211208A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  98. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-211209A
  99. IceCube-211208A - IceCube observation of a high-energy neutrino candidate track-like event
  100. IceCube Alert 211208.84: 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