Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

7301 results found.

  1. GRB 230116D: Swift detection of a burst
  2. IceCube-230112A: No Candidate Counterparts from the Zwicky Transient Facility
  3. IceCube-230112A - IceCube observation of a high-energy neutrino candidate track-like event
  4. GRB 221231A: 3.6m DOT optical upper limit
  5. IceCube-221223A: No Candidate Counterparts from the Zwicky Transient Facility
  6. GRB 221231A: Swift ToO observations
  7. IceCube-221229A - IceCube observation of a high-energy neutrino candidate track-like event
  8. GRB 221226B: Swift detection of a burst
  9. IceCube-221224A - IceCube observation of a high-energy neutrino candidate track-like event
  10. IceCube-221223A - IceCube observation of a high-energy neutrino candidate track-like event
  11. GRB 221218A: 3.6m DOT optical upper limit
  12. IceCube-221216A: No Candidate Counterparts from the Zwicky Transient Facility
  13. GRB 221218A: KAIT Optical Upper Limit
  14. IceCube-221210A: BOOTES-4/MET and Lijiang 2.4-meter Telescopes Optical Observations
  15. GRB 221216A: Swift detection of a burst
  16. IceCube-221216A - IceCube observation of a high-energy neutrino candidate track-like event
  17. GRB 221215A: Swift ToO observations
  18. IceCube-221210A - IceCube observation of a high-energy neutrino candidate track-like event
  19. GRB 221206B: Swift/BAT-GUANO candidate arcminute localization
  20. GRB 221206B: Swift ToO observations
  21. GRB 221202A: Swift detection of a burst
  22. GRB 221201A: Swift detection of a burst
  23. IceCube-221124A - IceCube observation of a high-energy neutrino candidate track-like event
  24. GRB 221120A: TURBO Optical Upper Limit
  25. GRB221120A: WIRC near-IR imaging of the afterglow candidate
  26. GRB 221120A: Liverpool Telescope Upper Limits
  27. GRB 221120A: Archival PS1 Imaging of Faint Source near XRT position
  28. GRB 221120A: LDT Optical Afterglow Candidate
  29. GRB 221120A: Swift detection of a likely short burst
  30. GRB 221110A: GRANDMA observations
  31. GRB 221110A: LCOGT Optical Afterglow Detection
  32. GRB 221110A: Swift detection of a burst with an optical counterpart
  33. IceCube-221104A - IceCube observation of a high-energy neutrino candidate track-like event
  34. GRB 221027B: Swift detection of a burst
  35. GRB 221024A: D50 candidate afterglow
  36. GRB 221022A: Swift ToO observations
  37. GRB 221009A: Determination of the black holes mass and spin
  38. GRB 221024A: Swift detection of a burst
  39. GRB 221022A: Swift/BAT-GUANO detection
  40. GRB 221017A: Swift ToO observations
  41. GRB 221009A: A type I BdHN of exceptional energetics
  42. GRB 221016A: Swift detection of a burst
  43. MAXI GRB 221006A: Redshifts of the possible host galaxies
  44. Afterglow limits of GRB 221006A from OHP
  45. GRB 221009A/Swift J1913.1+1946: SMA observations
  46. GRB 221006A: Swift ToO observations
  47. GRB 221009A / Swift J1913.1+1946: GIT detection of the optical afterglow
  48. GRB 221009A/Swift J1913.1+1946: AMI-LA observations
  49. Swift J1913.1+1946 a new bright hard X-ray and optical transient
  50. GRB 221008A: Tiled Swift observations
  51. GRB 221006A: Tiled Swift observations
  52. GRB 220921A: ATCA detection of radio counterpart
  53. GRB 220930A: Swift detection of a burst
  54. IceCube-220928A - IceCube observation of a high-energy neutrino candidate track-like event
  55. GRB 220921A: LCOGT Optical Observations
  56. GRB 220926A: Swift detection of a burst
  57. IceCube-220907A: Classification of AT2022oyn as a Type Ia supernova
  58. GRB 220921A: Tiled Swift observations
  59. IceCube-220918A - IceCube observation of a high-energy neutrino candidate track-like event
  60. GRB 220909A: Swift ToO observations
  61. GRB 220909A: Swift/BAT-GUANO candidate arcminute localization
  62. IceCube-220907A: One Candidate Counterpart from the Zwicky Transient Facility
  63. GRB 220831A: ATCA 5/9 GHz radio observations
  64. IceCube-220907A - IceCube observation of a high-energy neutrino candidate track-like event
  65. GRB 220831A: Swift-UVOT Upper Limits
  66. Introducing Self-Service Configuration of GCN Notices over Email for Transient Alerts
  67. GRB 220831A: DECam detection of a possible optical counterpart
  68. GRB 220831A: Swift ToO observations
  69. IceCube-220822A: Classification of AT2022saw as a Type Ia supernova
  70. GRB 220826A: Swift detection of a burst with an optical counterpart
  71. IceCube-220822A: One Candidate Counterpart from the Zwicky Transient Facility
  72. IceCube-220822A - IceCube observation of a high-energy neutrino candidate track-like event
  73. GRB 220810A: Further Swift-XRT observations
  74. GRB 220813A: Swift detection of a burst with an optical counterpart
  75. GRB 220810A: Swift-XRT observations
  76. GRB 220810A: Swift ToO observations
  77. GRB 220810A: MeerLICHT detection of two afterglow candidates
  78. GRB 220730A: Swift detection of a short hard burst
  79. Introducing new GCN Kafka broker and web site for transient alerts, https://gcn.nasa.gov
  80. GRB 220715B: Swift detection of a burst
  81. GRB 220714B: UVOT afterglow discovery
  82. GRB 220714B: Swift detection of a burst
  83. GRB 220712B: NOT optical afterglow confirmation
  84. GRB 220710A: Swift ToO observations
  85. GRB 220711B: NOT optical observations
  86. GRB 220711B: Swift detection of a burst
  87. IceCube-220624A: Classification of AT2022nit as a type Ia supernova and AT2021bei as an AGN
  88. GRB 220708B: Swift ToO observations
  89. GRB 220627A: ATCA detection of radio counterpart
  90. GRB 220706A: Swift detection of a burst
  91. GRB 220701A: Keck/LRIS Optical Upper Limit
  92. GRB 200701A: KAIT Optical Upper Limit
  93. GRB 220701A: Swift detection of a burst
  94. Fermi-LAT Gamma-ray Observations of IceCube-220627A
  95. IceCube-220629A - IceCube observation of a high-energy neutrino candidate track-like event
  96. GRB 220627A: Swift-XRT afterglow detection
  97. IceCube-220624A: One Candidate Counterpart from Swift/XRT follow up observations
  98. GRB 220627A: VLT MUSE redshift
  99. GRB 220627A: MeerLICHT candidate optical afterglow
  100. Fermi-LAT Gamma-ray Observations of IceCube-220624A and and detection of a new gamma-ray source, Fermi J1458.0+4119

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