Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

11546 results found.

  1. GRB 201020B: AGILE detection
  2. GRB 201021A: Fermi GBM Final Real-time Localization
  3. GRB 201020B: Fermi GBM detection
  4. GRB 201020A: Fermi GBM observation
  5. Fermi GRB 201020B: Global MASTER-Net observations report
  6. GRB 201020B: Fermi GBM Final Real-time Localization
  7. GRB 201019B: AstroSat CZTI detection
  8. GRB 201016A: Insight-HXMT/HE detection
  9. GRB 201017A: SAO RAS optical observations
  10. GRB 201017A: GROWTH-India optical upper limit
  11. GRB 201019B: Fermi GBM correction to GCN 28687
  12. GRB 201019A: Fermi GBM Final Real-time Localization
  13. GRB 201017A: MITSuME Akeno optical upper limits
  14. GRB 201019A: Fermi GBM Final Real-time Localization
  15. GRB 201017A: Assy and Mondy optical observations, possible afterglow detection
  16. GRB 201017A: Fermi GBM detection
  17. GRB 201015A: classification as long GRB
  18. GRB 201017A: Fermi GBM Final Real-time Localization
  19. Fermi GBM Sub-Threshold Detection of GRB 201015A
  20. GRB 201016A: AstroSat CZTI detection
  21. GRB 201008A: Swift-XRT afterglow detection
  22. GRB 201016A: Fermi GBM detection
  23. Fermi GRB 201016B: Global MASTER-Net observations report
  24. GRB 201016B: BALROG localization (Fermi Trigger 624510986 / GRB 201016136)
  25. GRB 201016A: BALROG localization (Fermi Trigger 624500874 / GRB 201016019)
  26. GRB 201016B: Fermi GBM Final Real-time Localization
  27. GRB 201016A: Fermi GBM Final Real-time Localization
  28. Fermi-LAT Gamma-ray Observations of IceCube-201014A
  29. IceCube-201014A: Not observable by GBM
  30. IceCube-201014A - IceCube observation of a high-energy neutrino candidate track-like event
  31. GRB 201011A: Fermi GBM detection of a likely Long GRB in the direction of SGR 1830-0645
  32. Fermi trigger No 624139481: AGILE detection
  33. GRB 201012A: Fermi GBM Final Real-time Localization
  34. Fermi trigger No 624139481: Global MASTER-Net observations report
  35. Fermi trigger No 624121589: Global MASTER-Net observations report
  36. GRB 201008B: Fermi GBM Final Localization
  37. GRB 201008A: Swift-XRT observations
  38. GRB 201008A: Swift ToO observations
  39. IceCube-201007A: Upper limits from Fermi-GBM Observations
  40. GRB 201008A: Swift/BAT-GUANO detection and possible arcminute localization
  41. Fermi-LAT Gamma-ray Observations of IceCube-201007A
  42. Fermi trigger No 623846261: Global MASTER-Net observations report
  43. Fermi trigger No 623873165: Global MASTER-Net observations report
  44. GRB 201008A: BALROG localization (Fermi Trigger 623846261 / GRB 201008443)
  45. IceCube-201007A - IceCube observation of a high-energy neutrino candidate track-like event
  46. Fermi GRB 201007A: Global MASTER-Net observations report
  47. GRB 201007A: Fermi GBM Final Real-time Localization
  48. GRB 201006A: Fermi GBM detection
  49. GRB 201006A is likely a short burst
  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: MITSuME Akeno optical upper limits
  54. GRB 201001A: Fermi GBM observation
  55. GRB 201001A: Fermi GBM Final Real-time Localization
  56. Fermi-LAT Gamma-ray Observations of IceCube-200929A
  57. IceCube-200929A: Upper limits from Fermi-GBM Observations
  58. GRB 200928B: Insight-HXMT/HE detection
  59. IceCube-200929A: IceCube observation of a high-energy neutrino candidate event
  60. IceCube-200926B: Upper limits from Fermi-GBM Observations
  61. IceCube-200926A: Upper limits from Fermi-GBM Observations
  62. Fermi GRB 200929A: Global MASTER-Net observations report
  63. GRB 200928B: AstroSat CZTI detection
  64. GRB 200929A: Fermi GBM Final Real-time Localization
  65. GRB 200928B: BALROG localization (Fermi Trigger 622991684 / GRB 200928552)
  66. GRB 200928B: Fermi GBM Final Real-time Localization
  67. Fermi-LAT Gamma-ray Observations of IceCube-200926B
  68. GRB 200928A: Fermi GBM Final Localization
  69. Fermi-LAT Gamma-ray Observations of IceCube-200926A
  70. IceCube-200926B: IceCube observation of a high-energy neutrino candidate event
  71. IceCube-200926A: IceCube observation of a high-energy neutrino candidate event
  72. Fermi GRB 200925A: Global MASTER-Net observations report
  73. GRB 200925A: Fermi GBM Final Real-time Localization
  74. Konus-Wind observation of GRB 200914A
  75. Fermi GRB 200924A: Global MASTER-Net observations report
  76. GRB 200924B: Fermi GBM Final Localization
  77. Fermi trigger No 622618714: Global MASTER-Net observations report
  78. GRB 200924A: Fermi GBM Final Real-time Localization
  79. Fermi GRB 200923A: Global MASTER-Net observations report
  80. GRB 200923A: Fermi GBM Final Real-time Localization
  81. Fermi-LAT Gamma-ray Observations of IceCube-200921A and detection of a new gamma-ray source, Fermi J1256.9+2630
  82. Fermi GRB 200922B: Global MASTER-Net observations report
  83. GRB 200922B: Fermi GBM Final Real-time Localization
  84. GRB 200919C: Insight-HXMT/HE detection
  85. IceCube-200921A: Upper limits from Fermi-GBM Observations
  86. IceCube-200921A: IceCube observation of a high-energy neutrino candidate event
  87. IPN triangulation of GRB 200920B (short)
  88. GRB 200920B: AGILE/MCAL detection of a burst
  89. GRB 200920A: Fermi GBM Final Real-time Localization
  90. Fermi GRB 200919C: Global MASTER-Net observations report
  91. GRB 200919C: Fermi GBM Final Real-time Localization
  92. Fermi GRB 200919B: Global MASTER-Net observations report
  93. GRB 200919B: Fermi GBM Final Real-time Localization
  94. Fermi-GBM Sub-Threshold Detection of GRB 200917A
  95. IceCube-200916A: Upper limits from Fermi-GBM Observations
  96. Fermi-LAT Gamma-ray Observations of IceCube-200916A
  97. IceCube-200916A - IceCube observation of a high-energy neutrino candidate track-like event
  98. Fermi GRB 200916A: Global MASTER-Net observations report
  99. GRB 200916A: Fermi GBM Final Real-time Localization
  100. Fermi trigger No 621893860: 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