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"

35441 results found.

  1. GRB 081128: optical observation in CrAO
  2. GRB081203A: Optical observations at Ishigaki
  3. GRB 081128: Optical afterglow observations
  4. GRB 081204: GROND Observations
  5. GRB081203B: optical observations
  6. Radio detection of GRB 081203B with the VLA
  7. GRB 081204: Magellan observations
  8. GRB081203A: Radio upper limit at 15 GHz
  9. GRB 081204B: Fermi GBM detection
  10. GRB 081204: Swift/UVOT Upper Limits
  11. GRB 081204: Swift XRT afterglow confirmation
  12. GRB081203A: MITSuME optical observation
  13. GRB 081203A: Optical observations of Xinglong TNT telescope
  14. GRB 081203A: Skynet/GORT Detections
  15. GRB 081204: Swift XRT afterglow candidate
  16. GRB081203A: optical observation
  17. GRB 081204 : a long GRB localized by INTEGRAL
  18. VLA Radio upper limit on GRB 081203A
  19. Swift-XRT observations of GRB 081203B
  20. Konus-Wind observation of GRB 081203A
  21. Konus-Wind observation of GRB 081203B
  22. GRB081203A: Swift-XRT refined analysis
  23. GRB 081203B: optical observations
  24. GRB 081203B: SDSS upper limits at the position of the optical afterglow
  25. Swift/UVOT detection of GRB081203B
  26. GRB 081203B: Swift-XRT candidate afterglow.
  27. GRB 081203A: optical observations
  28. Swift UVOT observations of GRB 081203A
  29. GRB 081203B: Naming correction for burst detected in Swift-BAT slew data
  30. GRB081203A: Swift/UVOT grism redshift
  31. GRB 081203A: Burst detection from Swift-BAT slew data
  32. GRB 081203A: Swift-BAT refined analysis
  33. GRB 081203: Enhanced Swift-XRT position
  34. GRB 081130B: MASTER prompt optical observations
  35. GRB081203: optical observation
  36. GRB 081203: Swift detection of a burst with a bright optical counterpart
  37. GRB 081128: optical observation
  38. GRB 081130B: Fermi GBM detection
  39. GRB 081130: Fermi GBM detection
  40. GRB 081126: afterglow photometry
  41. GRB 081126: Fermi GBM detection
  42. Fermi Gamma-ray Burst Monitor trigger 249166723 reclassification
  43. VLA Radio upper limit on GRB 081126
  44. GRB 081129: Fermi GBM detection
  45. GRB 081130: MASTER VWF prompt optical observations Fermi GRB
  46. GRB 081128A: optical observations
  47. Trigger 335971: Swift possible detection of a burst
  48. GRB081128: Swift/UVOT Upper Limits
  49. GRB 081122B: Fermi GBM Detection
  50. GRB 081128: Swift-XRT refined analysis
  51. GRB 081128: Liverpool Telescope afterglow confirmation
  52. GRB081128: optical observations
  53. GRB 081128: Swift-BAT refined analysis
  54. GRB 081128: Enhanced Swift-XRT position
  55. GRB 081128: Optical observation of xinglong TNT
  56. GRB 081128: Swift detection of a burst
  57. GRB 081126: Swift observations continuing
  58. GRB081126: Afterglow photometry from Crni Vrh
  59. GRB 081126: GRT Optical Observation
  60. GRB 081127: Swift/UVOT Upper Limits
  61. GRB 081127: Swift-XRT refined analysis
  62. GRB 081127: Enhanced Swift-XRT position
  63. GRB 081126: Confirmation of the Optical Afterglow
  64. GRB 081127: Swift-BAT refined analysis
  65. Konus-Wind observation of GRB 081126
  66. GRB 081126: Swift-XRT refined analysis
  67. GRB 081127: Swift detection of a burst
  68. GRB 081126: Swift/UVOT Observations
  69. GRB 081126: optical observations
  70. GRB 081126: Swift-BAT refined analysis
  71. GRB 081126: Enhanced Swift-XRT position
  72. GRB 081126: TAROT Calern observatory optical observations
  73. GRB 081126: Swift detection of a burst
  74. GRB 081125: Fermi GBM detection
  75. GRB 081124: Fermi GBM detection
  76. GRB 081120: Fermi GBM detection
  77. GRB 081118: Fermi GBM detection.
  78. GRB 081122: Fermi GBM detection
  79. Konus-Wind observation of GRB 081121
  80. GRB 081121, SMARTS optical/IR afterglow observations
  81. GRB081121: Fermi GBM detection
  82. Fermi GBM detection of a weak source
  83. GRB081121: Refined Swift/UVOT observations
  84. GRB 081121: Swift-XRT refined analysis
  85. GRB 081121: Magellan Redshift
  86. GRB 081121: Enhanced Swift-XRT position
  87. GRB 081121: GROND observations
  88. GRB 081121: Swift-BAT refined analysis
  89. GRB 081121: Swift detection of a burst
  90. GRB 081121: ROTSE-III Detection of Optical Counterpart
  91. GRB 081016b, SMARTS optical/IR observations
  92. GRB 081119: Fermi GBM detection
  93. VLA Radio upper limit on GRB 081118
  94. GRB 081118: VLT redshift
  95. GRB 081118: Swift-XRT refined analysis
  96. GRB 081118: GROND detection of afterglow
  97. GRB 081118: optical afterglow candidate
  98. GRB 081118: Swift UVOT Upper Limits
  99. GRB 081118: Swift-BAT refined analysis
  100. GRB 081118: Enhanced Swift-XRT position

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