Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"
  1. GRB 081102B: Fermi GBM detection
  2. GRB 081105B: Fermi GBM detection
  3. GRB 081107: Fermi GBM detection
  4. GRB 081104: GROND found no Optical/NIR Afterglow
  5. GRB 081105: GROND Upper Limits
  6. Radio observation of GRB 080523 with ATCA
  7. Radio observation of GRB 080520 with ATCA
  8. GRB 081105: Observations from OSN
  9. UVOT/Swift observations of GRB081105
  10. Swift-XRT observations of GRB 081105
  11. GRB 081101B: Fermi GBM detection
  12. Radio observation of GRB 080516 with ATCA
  13. GRB 081105 Swift/BAT and IPN Localization
  14. GRB 081025: Fermi GBM observation
  15. GRB 081104: GROND Detection of the Optical/NIR Afterglow Candidate?
  16. GRB 081104: refined XRT analysis
  17. GRB 081104: Enhanced Swift-XRT position
  18. GRB 081104: Swift-BAT refined analysis
  19. GRB081104: Swift/UVOT Upper Limits
  20. Fermi-GBM detection of a Solar Flare
  21. Fermi Detection of GRB 081102
  22. GRB 081104 : Faulkes Telescope South observations
  23. GRB 081104: Swift-XRT position
  24. GRB 081104: Swift detection of a burst
  25. Radio observation of GRB 080130 with ATCA
  26. GRB 081102: MASTER prompt optical limit
  27. GRB 081102: Swift-XRT refined analysis
  28. GRB 081102: Swift/UVOT refined analysis
  29. GRB 081102: Swift-BAT refined analysis
  30. GRB 081102: Enhanced Swift-XRT position
  31. Radio observation of GRB 080218b with ATCA
  32. Radio observation of GRB 080229a with ATCA
  33. GRB 081102: MASTER VWF promt observation
  34. GRB 081102: OPTIMA-Burst optical upper limit
  35. GRB 081102: Swift detection of a burst
  36. SGR 0501+4516: optical observations in August
  37. GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
  38. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  39. SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
  40. Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
  41. GRB 081024B: BTA deep optical observations
  42. GRB 081028: CrAO optical observations
  43. GRB 081024B: new Swift-XRT observations
  44. Radio observation of GRB 080229b with ATCA
  45. GRB 081029, SMARTS optical/IR afterglow observations
  46. GRB 081024B: VLA radio observation
  47. GRB 081029: UVOT Detection of the Optical Afterglow
  48. GRB 081029: PROMPT Detections
  49. GRB 081029: Redshift Confirmation from Gemini-South
  50. GRB 081029: Swift-BAT refined analysis
  51. GRB081029: Swift XRT refined analysis
  52. GRB 081025: Suzaku WAM observation of the prompt emission
  53. GRB 081024B: Suzaku WAM observation of the prompt emission
  54. GRB 081029: Enhanced Swift-XRT position
  55. GRB 081028: GROND Confirmation of the Optical/NIR Afterglow
  56. GRB 081029: REM observations
  57. Radio observation of GRB 080303 with ATCA
  58. Radio observation of GRB 080411 with ATCA
  59. GRB 081029: UVES/VLT Absorption Redshift
  60. GRB 081029: GROND Detection of the Optical/NIR Afterglow
  61. GRB 081029: ROTSE-III Detection of Optical Counterpart
  62. GRB 081029: Swift detection of a burst
  63. GRB 081028: Magellan redshift
  64. GRB 081028B: Fermi GBM detection
  65. GRB 081021: Fermi GBM detection
  66. GRB081028: UVOT detection of a brightening afterglow
  67. Swift UVOT observations of GRB081028
  68. GRB 081028: Swift-XRT refined analysis
  69. GRB 081028, Swift-BAT refined analysis
  70. GRB 081028: Enhanced Swift-XRT position
  71. GRB 081028: TAROT Calern observatory optical observations
  72. GRB 081028: optical observations at the NOT
  73. GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
  74. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  75. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  76. GRB 081028: Swift detection of a burst
  77. GRB 081025: TLS upper limits
  78. GRB 081024: No radio detection with the VLA
  79. GRB081025: RTT150 optical observations
  80. GRB081024B: P200 Observations
  81. GRB 081024B: Swift-XRT further observations
  82. GRB 081025 BAT refined analysis
  83. Swift UVOT observations of GRB081025
  84. Swift UVOT observations of GRB081024B
  85. Konus-Wind observation of GRB 081025
  86. GRB 081025: Swift-XRT position
  87. GRB 081024B: Swift-XRT observations
  88. GRB 081025: Burst detection from Swift-BAT slew data
  89. GRB 081024B: Fermi Gamma-ray Burst Monitor detection
  90. Fermi-LAT observation of GRB 081024B
  91. Swift UVOT observations of GRB 081024
  92. GRB 081024: Swift-XRT refined analysis
  93. GRB 081024, Swift-BAT refined analysis
  94. GRB 081024: Enhanced Swift-XRT position
  95. GRB 081024: Faulkes Telescope North optical observations
  96. GRB 081024: KAIT Optical Limits
  97. GRB 081024: Early Super-LOTIS Observations
  98. GRB 081024A: ROTSE-III Optical Limits
  99. GRB 081024: Swift detection of a burst
  100. GRB 081022, Swift-BAT refined analysis

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