Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
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"
  1. GRB 201013A: Swift detection of a burst
  2. GRB 201011A: Fermi GBM detection of a likely Long GRB in the direction of SGR 1830-0645
  3. Fermi trigger No 624139481: AGILE detection
  4. GRB 201012A: Fermi GBM Final Real-time Localization
  5. SGR 1830-0645: pre-discovery detection in Swift/BAT
  6. Fermi trigger No 624139481: Global MASTER-Net observations report
  7. SGR 1830-0645 / GRB 201010A: 1.5m OSN optical upper limit
  8. Fermi trigger No 624121589: Global MASTER-Net observations report
  9. SGR 1830-0645: Swift-BAT refined analysis
  10. GRB 201006A: Chandra upper limit on the X-ray afterglow
  11. SGR 1830-0645 / GRB 201010A: Kitab optical non-detection
  12. GRB 201010A: Enhanced Swift-XRT position
  13. Swift GRB201010.62: Global MASTER-Net observations report
  14. Swift detection of a new SGR 1830-0645 or a short GRB 201010A
  15. IceCube-200929A: JCMT/SCUBA2 observations
  16. IceCube-201007A: No significant detection in HAWC
  17. GRB 201008B: Fermi GBM Final Localization
  18. IceCube-201007A: Upper limits from a search for additional neutrino events in IceCube
  19. GRB 201009A: AstroSat CZTI detection
  20. GRB 201009A: AGILE detection of a burst
  21. GRB 201008A: Swift-XRT observations
  22. IceCube-200926A: Upper limits from Insight-HXMT Observations
  23. GRB 201008A: Swift ToO observations
  24. IceCube-201007A: Upper limits from Fermi-GBM Observations
  25. GRB 201008A: Swift/BAT-GUANO detection and possible arcminute localization
  26. Fermi-LAT Gamma-ray Observations of IceCube-201007A
  27. Fermi trigger No 623846261: Global MASTER-Net observations report
  28. Fermi trigger No 623873165: Global MASTER-Net observations report
  29. Swift-XRT observations of IceCube 201007A
  30. Baksan Neutrino Observatory Alert 201008.47: Global MASTER-Net observations report
  31. GRB 201008A: BALROG localization (Fermi Trigger 623846261 / GRB 201008443)
  32. IceCube-201007A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  33. IceCube-201007A - IceCube observation of a high-energy neutrino candidate track-like event
  34. IceCube Alert 201007.92: Global MASTER-Net observations report
  35. GRB 201006A: GROWTH-India Telescope optical upper limit
  36. GRB 201006A: Lowell Discovery Telescope upper limits
  37. GRB 201006A: MITSuME Akeno optical upper limits
  38. Fermi GRB 201007A: Global MASTER-Net observations report
  39. GRB 201007A: Fermi GBM Final Real-time Localization
  40. GRB 201006A: Swift-XRT refined Analysis
  41. GRB 201006A: Swift-BAT refined analysis
  42. Baksan Neutrino Observatory Alert 201006.88: Global MASTER-Net observations report
  43. GRB 201006A: Swift/UVOT Upper Limits
  44. GRB 201006A: Fermi GBM detection
  45. GRB 201006A is likely a short burst
  46. GRB 201006A: Enhanced Swift-XRT position
  47. INTEGRAL sub-threshold detection of GRB 201006A
  48. GRB 201006A: Swift detection of a burst
  49. Swift GRB201006.05: Global MASTER-Net observations report
  50. Fermi trigger No 623470566: Global MASTER-Net observations report
  51. GRB 201004A: Fermi GBM Final Localization
  52. Fermi trigger No 623493962: Global MASTER-Net observations report
  53. GRB 201001A: Swift/UVOT Upper Limits
  54. IceCube-200926A: No usable INTEGRAL data
  55. IceCube-200926B: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  56. IceCube-200929A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  57. IceCube-200926A: No candidate counterparts from the Zwicky Transient Facility
  58. GRB 201001A: TSHAO optical upper limit
  59. GRB 201001A: Xinglong-2.16m optical upper limit
  60. GRB 201001A: MITSuME Akeno optical upper limits
  61. IceCube-200926A: JCMT/SCUBA2 observations
  62. IceCube-200929A: No significant detection in HAWC
  63. GRB 201001A: Swift-BAT refined analysis
  64. GRB 201001A: Swift-XRT refined Analysis
  65. IceCube-200929A: Upper limits from a search for additional neutrino events in IceCube
  66. GRB 201001A: Fermi GBM observation
  67. Swift-XRT observations of IceCube 200929A
  68. GRB 201001A: Enhanced Swift-XRT position
  69. GRB 201001A: Swift detection of a burst
  70. GRB 201001A: Fermi GBM Final Real-time Localization
  71. Fermi-LAT Gamma-ray Observations of IceCube-200929A
  72. IceCube-200929A: Upper limits from Fermi-GBM Observations
  73. IceCube-200929A: No neutrino counterpart candidates in ANTARES search
  74. IceCube-200926B: No significant detection in HAWC
  75. GRB 200928B: Insight-HXMT/HE detection
  76. IceCube-200929A: IceCube observation of a high-energy neutrino candidate event
  77. IceCube-200926B: Upper limits from Fermi-GBM Observations
  78. IceCube-200926A: Upper limits from Fermi-GBM Observations
  79. IceCube Alert 200929.74: Global MASTER-Net observations report
  80. IceCube-200926A: No significant detection in HAWC
  81. Fermi GRB 200929A: Global MASTER-Net observations report
  82. GRB 200928B: AstroSat CZTI detection
  83. GRB 200929A: Fermi GBM Final Real-time Localization
  84. IceCube-200926B: Upper limits from a search for additional neutrino events in IceCube
  85. IceCube-200926A: Upper limits from a search for additional neutrino events in IceCube
  86. GRB 200928B: BALROG localization (Fermi Trigger 622991684 / GRB 200928552)
  87. GRB 200928B: Fermi GBM Final Real-time Localization
  88. IceCube-200926A: No Candidate Counterparts from the Zwicky Transient Facility
  89. Fermi-LAT Gamma-ray Observations of IceCube-200926B
  90. GRB 200928A: Fermi GBM Final Localization
  91. IceCube-200926B: No neutrino counterpart candidates in ANTARES search
  92. IceCube Alert 200926.94: Global MASTER-Net observations report
  93. Swift-XRT observations of IceCube 200926A
  94. Konus-Wind detection of GRB 200920B
  95. Fermi-LAT Gamma-ray Observations of IceCube-200926A
  96. GRB 200925B: Swift-XRT refined analysis update
  97. GRB 200925B NUTTelA-TAO / BSTI Early Measurements (Preliminary)
  98. IceCube Alert 200926.33: Global MASTER-Net observations report
  99. IceCube-200926B: IceCube observation of a high-energy neutrino candidate event
  100. GRB 200925B: Swift-XRT refined Analysis

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