Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. 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"

11848 results found.

  1. GRB 210919A OSN 1.5m Source Confirmation
  2. IceCube-210922A: No significant detection in HAWC
  3. GRB 210919A: DECam Upper Limits
  4. Fermi-LAT Gamma-ray Observations of IceCube-210922A
  5. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 September 22
  6. GRB 210912A: LBT optical observations
  7. GRB 210919A: AbAO optical upper limit
  8. Swift GRB 210919A: Global MASTER-Net observations report
  9. Swift trigger 1073821: detection of IGR J16418-4532
  10. Konus-Wind observation of the recent SGR 1935+2154 activity
  11. AGILE observations of two bright bursts from SGR 1935+2154
  12. GRB 210912A: CAHA 2.2m Detection
  13. GRB 210912A: Swift-XRT refined Analysis
  14. Fermi GBM observation of another bright burst in the direction of SGR 1935+2154
  15. Swift GRB 210912A: Global MASTER-Net observations report
  16. GRB 210912A: Swift detection of a burst
  17. Fermi trigger No 653084584: Global MASTER-Net observations report
  18. Fermi trigger No 653083551: Global MASTER-Net observations report
  19. Fermi trigger No 653072474: Global MASTER-Net observations report
  20. Fermi trigger No 653054042: Global MASTER-Net observations report
  21. Fermi trigger No 653049776: Global MASTER-Net observations report
  22. Fermi trigger No 653022153: Global MASTER-Net observations report
  23. Swift GRB210910.42: Global MASTER-Net observations report
  24. Konus-Wind detection of the second intermediate flare from SGR 1935+2154
  25. Fermi trigger No 652981861: Global MASTER-Net observations report
  26. Fermi trigger No 652934203: Global MASTER-Net observations report
  27. Fermi trigger No 652927551: Global MASTER-Net observations report
  28. GRB 210619B: Maidanak and Assy optical observations, broken power law parametrization
  29. Fermi trigger No 652911693: Global MASTER-Net observations report
  30. Fermi trigger No 652906639: Global MASTER-Net observations report
  31. Fermi GRB 210909A: Global MASTER-Net observations report
  32. GRB 210905A: ATCA detection
  33. GRB 210905A: ALMA detection
  34. GRB 210905A: AstroSat CZTI detection
  35. Fermi trigger No 652585475: Global MASTER-Net observations report
  36. GRB 210905A: Swift-XRT refined Analysis
  37. GRB 210610A: Maidanak and AbAO optical observations
  38. GRB 210827B: GECAM detection
  39. Fermi GRB 210904A: Global MASTER-Net observations report
  40. GRB 210904A: Fermi GBM Final Real-time Localization
  41. GRB 210901A: GROND observations
  42. Fermi GBM observation of a burst from SGR J1555.2-5402
  43. Integral GRB210829.14: Global MASTER-Net observations report
  44. GRB 210826A: AstroSat CZTI detection
  45. Fermi GRB 210827A: Global MASTER-Net observations report
  46. Fermi GRB 210827B: Global MASTER-Net observations report
  47. GRB 210826A: Fermi-LAT detection
  48. GRB 210824A: MITSuME Akeno optical upper limits
  49. GRB 210822A: TSHAO continued optical observation
  50. GRB 210822A: VLA detection
  51. GRB 210822A: TSHAO optical observation
  52. GRB 210824A: Swift-XRT refined Analysis
  53. GRB 210824A: Swift detection of a burst
  54. GRB 210822A: GECAM refined analysis
  55. Konus-Wind detection of GRB 210822A
  56. GRB 210822A: AstroSat CZTI detection
  57. GRB 210822A: Swift-BAT refined analysis
  58. GRB 210820A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  59. GRB 210822A: Fermi-LAT detection
  60. Fermi GRB 210822B: Global MASTER-Net observations report
  61. GRB 210822A: KAIT Optical Afterglow Confirmation
  62. GRB 210820A: LCO Optical Upper Limit
  63. GRB 210820A: Nanshan/NEXT optical upper limit
  64. GRB 210820A: Swift-XRT refined Analysis
  65. Swift GRB 210820A: Global MASTER-Net observations report
  66. GRB 210820B: Fermi GBM Final Localization
  67. Fermi trigger No 651110719: Global MASTER-Net observations report
  68. Konus-Wind detection of GRB 210818A
  69. GRB 210818A: AstroSat CZTI detection
  70. GRB 210818A: AGILE detection
  71. Fermi trigger No 650687034: Global MASTER-Net observations report
  72. Fermi-LAT Gamma-ray Observations of IceCube-210811A
  73. GRB 210807A: continued Assy, AbAO and Mondy observations
  74. SGR 1935+2154: SPI INTEGRAL observations on 2021 August 5
  75. GRB 210730A: Tautenburg observations
  76. GRB 210807A: Tautenburg observations
  77. IceCube Alert 210811.09: Global MASTER-Net observations report
  78. GRB 210807C: Swift-BAT refined analysis
  79. GRB 210610B: Assy optical observations
  80. Fermi GRB 210807C: Global MASTER-Net observations report
  81. Swift GRB210807.96: Global MASTER-Net observations report
  82. GRB 210807C: Swift detection of a burst
  83. Fermi GRB 210807B: Global MASTER-Net observations report
  84. Swift GRB210807.78: Global MASTER-Net observations report
  85. GRB 210807A: BOOTES-5/JGT optical afterglow detection
  86. GRB 210807A: Swift detection of a burst with an optical counterpart
  87. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 August 5
  88. Fermi trigger No 649814537: Global MASTER-Net observations report
  89. GRB 210802A: BOOTES-2/TELMA optical upper limit
  90. GRB 210802A: Fermi GBM detection
  91. GRB 210802A: Fermi-LAT detection
  92. Fermi trigger No 649627691: Global MASTER-Net observations report
  93. Swift GRB210731.62: Global MASTER-Net observations report
  94. GRB 210731A: MeerLICHT optical afterglow detection
  95. GRB210731A: Enhanced Swift-XRT position
  96. Swift GRB210731.93: Global MASTER-Net observations report
  97. Fermi-LAT Gamma-ray Observations of IceCube-210730A
  98. GRB 210730A: BOOTES-5/JGT and 2.2m CAHA telescopes optical limit
  99. Fermi trigger No 649390368: Global MASTER-Net observations report
  100. GRB 210730A: AstroSat CZTI detection

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