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"

36192 results found.

  1. GRB 210827B: BALROG localization (Fermi Trigger 651751821 / GRB 210827424)
  2. GRB 210827B: Fermi GBM Final Real-time Localization
  3. GRB 210826A: Swift-XRT observations
  4. GRB 210827A: Fermi GBM Final Real-time Localization
  5. GRB 210822A: CAHA 2.2m observations
  6. GRB 210824A: Swift-BAT refined analysis
  7. GRB 210826A: Fermi-LAT detection
  8. Fermi GRB 210826A: Global MASTER-Net observations report
  9. GRB 210826A: Tiled Swift observations
  10. GRB 210824A: MITSuME Akeno optical upper limits
  11. GRB 210826A: BALROG localization (Fermi Trigger 651654110 / GRB 210826293)
  12. GRB 210826A: Fermi GBM Final Real-time Localization
  13. GRB 210822A: TSHAO continued optical observation
  14. GRB 210822A: VLA detection
  15. GRB 210822A: TSHAO optical observation
  16. GRB 210822A: Swift/UVOT Detection
  17. Swift GRB 210824A: Global MASTER-Net observations report
  18. GRB 210824A: BOOTES-5/JGT optical upper limit
  19. GRB 210824A: Fermi GBM Observation
  20. Fermi GRB 210824A: Global MASTER-Net observations report
  21. GRB 210824A: Nanshan/NEXT optical upper limit
  22. GRB 210824A: Swift-XRT refined Analysis
  23. GRB 210822A: GROND observations
  24. GRB 210824A: Enhanced Swift-XRT position
  25. GRB 210822A: Abbey Ridge Observatory optical afterglow observation
  26. GRB 210824A: Swift detection of a burst
  27. GRB 210824A: Fermi GBM Final Real-time Localization
  28. GRB 210822B: DDOTI Upper Limits on the Afterglow
  29. GRB 210822A: Detection by GRBAlpha
  30. GRB 210822A: GECAM refined analysis
  31. GRB 210820A: GROND observations
  32. Konus-Wind detection of GRB 210822A
  33. GRB 210822A: AstroSat CZTI detection
  34. GRB 210822A: NOT photometry and spectroscopy
  35. GRB 210822A: Swift-XRT refined Analysis
  36. GRB 210822A: Swift-BAT refined analysis
  37. GRB 210820A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  38. GRB 210822A: Fermi-LAT detection
  39. GRB 210820A: Swift/UVOT Detection
  40. Fermi GRB 210822B: Global MASTER-Net observations report
  41. GRB 210822A: Nanshan/NEXT optical observations
  42. GRB 210822B: Fermi GBM Final Real-time Localization
  43. GRB 210822A: Enhanced Swift-XRT position
  44. Swift GRB 210822A: Global MASTER-Net observations report
  45. GRB 210822A: RATIR Optical Detections
  46. GRB 210822A: KAIT Optical Afterglow Confirmation
  47. GRB 210822A: GECAM detection
  48. GRB 210822A: Swift detection of a burst with an optical afterglow
  49. Fermi GRB 210821A: Global MASTER-Net observations report
  50. GRB 210820A: Swift-BAT refined analysis
  51. GRB 210820A: LT optical upper limit
  52. GRB 210820A: LCO Optical Upper Limit
  53. GRB 210820A: RATIR Optical Detections
  54. GRB 210821A: Fermi GBM Final Real-time Localization
  55. GRB 210820A: NOT optical upper limit
  56. GRB 210820A: Nanshan/NEXT optical upper limit
  57. GRB 210820A: Swift-XRT refined Analysis
  58. GRB 210820A: Enhanced Swift-XRT position
  59. Swift GRB 210820A: Global MASTER-Net observations report
  60. GRB 210820B: Fermi GBM Final Localization
  61. GRB 210820A: Swift detection of a burst with an optical counterpart
  62. Swift GRB 210818A: Global MASTER-Net observations report
  63. GRB 210818A: Swift-XRT refined Analysis
  64. GRB 210818A: Swift-BAT refined analysis
  65. GRB 210726A: VLA radio afterglow detection
  66. Konus-Wind detection of GRB 210818A
  67. GRB 210818A: AstroSat CZTI detection
  68. GRB 210818A: AGILE detection
  69. GRB 210818A: Enhanced Swift-XRT position
  70. GRB 210818A: Swift detection of a burst with an optical counterpart
  71. IceCube-210811A: Upper limits from Fermi-GBM Observations
  72. GRB 210815A: BALROG localization (Fermi Trigger 650687034 / GRB 210815100)
  73. GRB 210815A: Fermi GBM Final Real-time Localization
  74. GRB 210812A is consistent with being a lensed GRB
  75. GRB 210712A: Fermi GBM observation
  76. GRB 210813A: BALROG localization (Fermi Trigger 650508868 / GRB 210813038)
  77. Fermi GRB 210813A: Global MASTER-Net observations report
  78. GRB 210813A: Fermi GBM Final Real-time Localization
  79. Retraction of Fermi GBM GCN 30630 and GCN 30632
  80. GRB 210807A: continued Assy, AbAO and Mondy observations
  81. Fermi GRB 210812A: Global MASTER-Net observations report
  82. GRB 210812B: Fermi GBM Final Real-time Localization
  83. GRB 210812A: BALROG localization (Fermi Trigger 650479626 / GRB 210812699)
  84. GRB 210812A: Fermi GBM Final Real-time Localization
  85. GRB 080102A: Fermi GBM Final Real-time Localization
  86. SGR 1935+2154: SPI INTEGRAL observations on 2021 August 5
  87. GRB 080101A: Fermi GBM Final Real-time Localization
  88. GRB 210730A: Tautenburg observations
  89. GRB 210807A: Tautenburg observations
  90. GRB 210807C: Swift-BAT refined analysis
  91. GRB 210807A: Detection by GRBAlpha
  92. GRB 210807A: Swift-BAT refined analysis
  93. GRB 210802A: Further Swift/XRT observation and afterglow confirmation
  94. GRB 210807C: Swift-XRT refined Analysis
  95. GRB 210807C: Fermi GBM detection
  96. GRB 210807C: Swift/UVOT Upper Limits
  97. GRB 210807A: Swift/UVOT Detection
  98. GRB 210807A: Swift-XRT refined Analysis
  99. GRB 210807A: correction to the GCN Circ. #30614 Assy optical observations
  100. GRB 210807C: Enhanced Swift-XRT position

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