Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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"

10778 results found.

  1. Fermi trigger No 683537972: Global MASTER-Net observations report
  2. Fermi trigger No 683476673: Global MASTER-Net observations report
  3. Konus-Wind detection of GRB 220826A
  4. Fermi trigger No 683202084: Global MASTER-Net observations report
  5. Fermi trigger No 683183601: Global MASTER-Net observations report
  6. GRB 220826A: Swift-XRT refined Analysis
  7. GRB 220826A: Swift detection of a burst with an optical counterpart
  8. GRB 220825A: Swift/BAT-GUANO detection
  9. IceCube-220822A: Upper limits from a search for additional neutrino events in IceCube
  10. Fermi-LAT gamma-ray observations of IceCube-220822A and detection of a new gamma-ray source, Fermi J1810.1+2154
  11. Fermi trigger No 682918137: Global MASTER-Net observations report
  12. GRB 220823A: Swift/BAT-GUANO detection of a short burst
  13. IceCube-220822A - IceCube observation of a high-energy neutrino candidate track-like event
  14. IceCube Alert 220822.85: Global MASTER-Net observations report
  15. Konus-Wind detection of GRB 220813A
  16. GRB 220813A: Swift-XRT refined Analysis
  17. GRB 220813A: Swift detection of a burst with an optical counterpart
  18. Fermi trigger No 681998863: Global MASTER-Net observations report
  19. GRB 220810A: MeerLICHT detection of two afterglow candidates
  20. Fermi trigger No 681890304: Global MASTER-Net observations report
  21. Swift GRB220806.76: Global MASTER-Net observations report
  22. GRB 220803A: AstroSat CZTI detection
  23. Konus-Wind detection of GRB 220730A (short)
  24. GRB 220729A: AstroSat CZTI detection
  25. Fermi trigger No 680782656: Global MASTER-Net observations report
  26. Fermi GRB 220728A: Global MASTER-Net observations report
  27. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-220728A
  28. GRB 220728A: Fermi GBM Final Real-time Localization
  29. Fermi GRB 220724A: Global MASTER-Net observations report
  30. Introducing new GCN Kafka broker and web site for transient alerts, https://gcn.nasa.gov
  31. GRB 220715B: Swift-BAT refined analysis
  32. GRB 220714B: Swift-XRT refined Analysis
  33. GRB 220714B: Swift detection of a burst
  34. GRB 220714A: Possible Swift detection of a burst
  35. GRB 220710A: Swift-XRT afterglow detection
  36. GRB 220711C: Swift/BAT-GUANO detection outside the coded FOV
  37. GRB 220711B, GROND observations
  38. Konus-Wind detection of GRB 220711C
  39. Fermi trigger No 679248723: Global MASTER-Net observations report
  40. Fermi GRB 220711B: Global MASTER-Net observations report
  41. GRB 220710A: Swift/BAT-GUANO arcminute localization
  42. GRB 220711B: Swift-XRT refined Analysis
  43. GRB 220711B: Swift detection of a burst
  44. GRB 220707A: AstroSat CZTI detection
  45. GRB 220708B: GIT optical upper limits
  46. GRB 220708B: T193-OHP optical upper limit
  47. Konus-Wind detection of GRB 220708B
  48. GRB 220708B: Swift-XRT afterglow detection
  49. GRB 220708B: Swift/BAT-GUANO arcminute localization
  50. GRB 220708A: Swift-XRT observations
  51. GRB 220706A: Swift-XRT refined Analysis
  52. GRB 220706A, GROND observations
  53. GRB 220706A: MAXI/GSC detection 84 minutes after the Swift Trigger
  54. GRB 220702B: AstroSat CZTI detection
  55. GRB 220706A: Nanshan/NEXT optical upper limits
  56. GRB 220706A: Swift detection of a burst
  57. GRB 220702B: Fermi GBM Final Localization
  58. Alert from the HAWC Burst Monitor HAWC-220702A
  59. GRB 220627A: AstroSat CZTI detection
  60. GRB 220701A: Swift-XRT refined Analysis
  61. GRB 220701A: BOOTES-5/JGT early optical upper limit
  62. GRB 200701A: KAIT Optical Upper Limit
  63. GRB 220701A: Swift detection of a burst
  64. Fermi-LAT Gamma-ray Observations of IceCube-220629A
  65. GRB 220627A, GROND observations
  66. GRB 220624A: AGILE/GRID refined analysis
  67. Fermi-LAT Gamma-ray Observations of IceCube-220627A
  68. Konus-Wind detection of GRB 220627A
  69. IceCube-220624A: One Candidate Counterpart from Swift/XRT follow up observations
  70. GRB 220627A: Fermi GBM Detection of a possible Lensed or Ultra-long GRB
  71. GRB 220627A: Swift/BAT-GUANO detection outside the coded FOV
  72. Konus-Wind detection of GRB 220624A
  73. Fermi-LAT Gamma-ray Observations of IceCube-220624A and and detection of a new gamma-ray source, Fermi J1458.0+4119
  74. GRB 220627A: Fermi-LAT detection
  75. IceCube Alert 220627.74: Global MASTER-Net observations report
  76. GRB 220624A: CALET Gamma-Ray Burst Monitor detection
  77. IPN triangulation of GRB 220624A
  78. GRB 220624A: Swift/BAT-GUANO detection outside the coded FOV
  79. GRB 220624A: AGILE/GRID analysis
  80. GRB 220624A: AGILE detection
  81. Konus-Wind detection of GRB 220623A
  82. GRB 220624B: Fermi GBM Final Real-time Localization
  83. GRB 220623A: Swift-XRT refined Analysis
  84. Konus-Wind detection of GRB 220609B
  85. GRB 220623A: AGILE detection
  86. GRB 220623A: AstroSat CZTI detection
  87. GRB 220623A: Swift-XRT observations
  88. Konus-Wind detection of GRB 220617A
  89. Fermi trigger No 677377371: Global MASTER-Net observations report
  90. Fermi GRB 220620B: Global MASTER-Net observations report
  91. Fermi GRB 220620A: Global MASTER-Net observations report
  92. GRB 220620B: Fermi GBM Final Real-time Localization
  93. Integral GRB220619.53: Global MASTER-Net observations report
  94. GRB 220619A: AstroSat CZTI detection
  95. Swift GRB220620.02: Global MASTER-Net observations report
  96. GRB 220620A: Fermi GBM Final Real-time Localization
  97. Fermi trigger No 677307509: Global MASTER-Net observations report
  98. Swift Trigger 1110865 is probably not an astrophysical event
  99. GRB 220618A: BOOTES-5/JGT early optical upper limit
  100. Swift GRB220618.38: Global MASTER-Net observations report

Advanced

Download all Circulars as a .tar.gz archive:
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