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. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  2. GRB081222: REM candidate afterglow
  3. GRB 081222: Swift detection of a burst with a bright optical afterglow
  4. GRB 081221: Enhanced Swift-XRT position
  5. GRB 081221: further NOT observations
  6. GRB 081221: NOT observations
  7. GRB 081221: Swift detection of a burst
  8. GRB 081217: Fermi GBM detection
  9. Modification of Swift/UVOT response to bright GRBs
  10. GRB081215A: Fermi-LAT observations
  11. GRB 081211B: Further Swift-XRT analysis
  12. GRB 081215B: Fermi GBM detection
  13. GRB 081216: Suzaku WAM observation of the prompt emission
  14. GRB 081216 : Fermi GBM observation
  15. GRB 081215A: Fermi GBM detection (correction to event fluence)
  16. GRB 081215A: Fermi GBM detection
  17. IPN localization of short hard GRB 081216
  18. GRB 081211B - possibly a short burst with extended emission
  19. GRB 081118: Zadko observations
  20. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  21. GRB 081215A: Gamma Repeater?
  22. GRB 0811215A: MASTER prompt optical observations
  23. GRB 081215A: Andromeda inside Fermi error box: MASTER observations
  24. GRB 0811215A: Andromeda inside Fermi error box: MASTER observations
  25. Possible GRB 081211B: Swift/UVOT Upper Limits
  26. GRB 081213: Fermi GBM detection
  27. GRB 081210: optical observations
  28. Possible GRB 081211B - Swift-XRT analysis
  29. GRB 081207: Fermi GBM detection
  30. GRB 081209: Fermi GBM detection
  31. Fermi Gamma-ray Burst Monitor trigger 250533995 is not a GRB
  32. GRB 081007: Detection of a Supernova
  33. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  34. GRB 081210: Xinglong TNT R band Upper Limits
  35. GRB 081210, SMARTS optical/IR observations
  36. GRB 081211: Swift-BAT refined analysis
  37. GRB 081211: Swift XRT refined analysis
  38. GRB 081211: Swift/UVOT detection of an optical afterglow
  39. GRB 081211: Enhanced Swift-XRT position
  40. GRB 081210: Swift/UVOT refined analysis
  41. GRB 081211: Swift detection of a burst
  42. GRB 081210: Swift-XRT refined analysis
  43. GRB081203B: optical observations
  44. GRB 081210: Enhanced Swift-XRT position
  45. GRB 081210: Swift-BAT refined analysis
  46. GRB 081210: Swift detection of a burst with optical afterglow
  47. Konus-Wind observation of GRB 081209
  48. IPN triangulation of short hard GRB 081209
  49. GRB 081203A: optical observations
  50. GRB 081206C: Fermi GBM detection
  51. Radio observation of GRB 081121 with ATCA
  52. Radio observation of GRB 081118 with ATCA
  53. GRB 081206B: Fermi GBM detection
  54. GRB 081206: Fermi GBM detection
  55. GRB 081128: afterglow observations
  56. GRB 081203B: Suzaku WAM observation of the prompt emission
  57. GRB 081203B: Additional Gemini imaging
  58. Radio observation of GRB 081109 with ATCA
  59. Radio observation of GRB 081104 with ATCA
  60. Radio observation of GRB 081029 with ATCA
  61. Radio observation of GRB 081008 with ATCA
  62. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  63. GRB 081203B: Gemini observations
  64. GRB 081128: optical observation in CrAO
  65. GRB081203A: Optical observations at Ishigaki
  66. GRB 081128: Optical afterglow observations
  67. GRB 081204: GROND Observations
  68. GRB081203B: optical observations
  69. Radio detection of GRB 081203B with the VLA
  70. GRB 081204: Magellan observations
  71. GRB081203A: Radio upper limit at 15 GHz
  72. GRB 081204B: Fermi GBM detection
  73. GRB 081204: Swift/UVOT Upper Limits
  74. GRB 081204: Swift XRT afterglow confirmation
  75. GRB081203A: MITSuME optical observation
  76. GRB 081203A: Optical observations of Xinglong TNT telescope
  77. GRB 081203A: Skynet/GORT Detections
  78. GRB 081204: Swift XRT afterglow candidate
  79. GRB081203A: optical observation
  80. GRB 081204 : a long GRB localized by INTEGRAL
  81. VLA Radio upper limit on GRB 081203A
  82. Swift-XRT observations of GRB 081203B
  83. Konus-Wind observation of GRB 081203A
  84. Konus-Wind observation of GRB 081203B
  85. GRB081203A: Swift-XRT refined analysis
  86. GRB 081203B: optical observations
  87. GRB 081203B: SDSS upper limits at the position of the optical afterglow
  88. Swift/UVOT detection of GRB081203B
  89. GRB 081203B: Swift-XRT candidate afterglow.
  90. GRB 081203A: optical observations
  91. Swift UVOT observations of GRB 081203A
  92. GRB 081203B: Naming correction for burst detected in Swift-BAT slew data
  93. GRB081203A: Swift/UVOT grism redshift
  94. GRB 081203A: Burst detection from Swift-BAT slew data
  95. GRB 081203A: Swift-BAT refined analysis
  96. GRB 081203: Enhanced Swift-XRT position
  97. GRB 081130B: MASTER prompt optical observations
  98. GRB081203: optical observation
  99. GRB 081203: Swift detection of a burst with a bright optical counterpart
  100. GRB 081128: optical observation

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