Skip to main content
Retirement of GCN Classic VOEvent Brokers. 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. Radio observation of GRB 080523 with ATCA
  2. Radio observation of GRB 080520 with ATCA
  3. GRB 081105: Observations from OSN
  4. UVOT/Swift observations of GRB081105
  5. Swift-XRT observations of GRB 081105
  6. GRB 081101B: Fermi GBM detection
  7. Radio observation of GRB 080516 with ATCA
  8. GRB 081105 Swift/BAT and IPN Localization
  9. GRB 081025: Fermi GBM observation
  10. GRB 081104: GROND Detection of the Optical/NIR Afterglow Candidate?
  11. GRB 081104: refined XRT analysis
  12. GRB 081104: Enhanced Swift-XRT position
  13. GRB 081104: Swift-BAT refined analysis
  14. GRB081104: Swift/UVOT Upper Limits
  15. Fermi-GBM detection of a Solar Flare
  16. Fermi Detection of GRB 081102
  17. GRB 081104 : Faulkes Telescope South observations
  18. GRB 081104: Swift-XRT position
  19. GRB 081104: Swift detection of a burst
  20. Radio observation of GRB 080130 with ATCA
  21. GRB 081102: MASTER prompt optical limit
  22. GRB 081102: Swift-XRT refined analysis
  23. GRB 081102: Swift/UVOT refined analysis
  24. GRB 081102: Swift-BAT refined analysis
  25. GRB 081102: Enhanced Swift-XRT position
  26. Radio observation of GRB 080218b with ATCA
  27. Radio observation of GRB 080229a with ATCA
  28. GRB 081102: MASTER VWF promt observation
  29. GRB 081102: OPTIMA-Burst optical upper limit
  30. GRB 081102: Swift detection of a burst
  31. SGR 0501+4516: optical observations in August
  32. GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
  33. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  34. SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
  35. Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
  36. GRB 081024B: BTA deep optical observations
  37. GRB 081028: CrAO optical observations
  38. GRB 081024B: new Swift-XRT observations
  39. Radio observation of GRB 080229b with ATCA
  40. GRB 081029, SMARTS optical/IR afterglow observations
  41. GRB 081024B: VLA radio observation
  42. GRB 081029: UVOT Detection of the Optical Afterglow
  43. GRB 081029: PROMPT Detections
  44. GRB 081029: Redshift Confirmation from Gemini-South
  45. GRB 081029: Swift-BAT refined analysis
  46. GRB081029: Swift XRT refined analysis
  47. GRB 081025: Suzaku WAM observation of the prompt emission
  48. GRB 081024B: Suzaku WAM observation of the prompt emission
  49. GRB 081029: Enhanced Swift-XRT position
  50. GRB 081028: GROND Confirmation of the Optical/NIR Afterglow
  51. GRB 081029: REM observations
  52. Radio observation of GRB 080303 with ATCA
  53. Radio observation of GRB 080411 with ATCA
  54. GRB 081029: UVES/VLT Absorption Redshift
  55. GRB 081029: GROND Detection of the Optical/NIR Afterglow
  56. GRB 081029: ROTSE-III Detection of Optical Counterpart
  57. GRB 081029: Swift detection of a burst
  58. GRB 081028: Magellan redshift
  59. GRB 081028B: Fermi GBM detection
  60. GRB 081021: Fermi GBM detection
  61. GRB081028: UVOT detection of a brightening afterglow
  62. Swift UVOT observations of GRB081028
  63. GRB 081028: Swift-XRT refined analysis
  64. GRB 081028, Swift-BAT refined analysis
  65. GRB 081028: Enhanced Swift-XRT position
  66. GRB 081028: TAROT Calern observatory optical observations
  67. GRB 081028: optical observations at the NOT
  68. GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
  69. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  70. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  71. GRB 081028: Swift detection of a burst
  72. GRB 081025: TLS upper limits
  73. GRB 081024: No radio detection with the VLA
  74. GRB081025: RTT150 optical observations
  75. GRB081024B: P200 Observations
  76. GRB 081024B: Swift-XRT further observations
  77. GRB 081025 BAT refined analysis
  78. Swift UVOT observations of GRB081025
  79. Swift UVOT observations of GRB081024B
  80. Konus-Wind observation of GRB 081025
  81. GRB 081025: Swift-XRT position
  82. GRB 081024B: Swift-XRT observations
  83. GRB 081025: Burst detection from Swift-BAT slew data
  84. GRB 081024B: Fermi Gamma-ray Burst Monitor detection
  85. Fermi-LAT observation of GRB 081024B
  86. Swift UVOT observations of GRB 081024
  87. GRB 081024: Swift-XRT refined analysis
  88. GRB 081024, Swift-BAT refined analysis
  89. GRB 081024: Enhanced Swift-XRT position
  90. GRB 081024: Faulkes Telescope North optical observations
  91. GRB 081024: KAIT Optical Limits
  92. GRB 081024: Early Super-LOTIS Observations
  93. GRB 081024A: ROTSE-III Optical Limits
  94. GRB 081024: Swift detection of a burst
  95. GRB 081022, Swift-BAT refined analysis
  96. GRB 081016A: Swift-XRT refined analysis
  97. GRB 081022: Swift detection of a burst
  98. GRB 081012: Swift-XRT Refined Analysis
  99. Swift trigger 332287 is not a GRB
  100. Swift detection of a possible burst (trigger 332287)

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