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"

26355 results found.

  1. GRB 051008: early Swift XRT analysis
  2. GRB 051008: Swift UVOT Candidate
  3. GRB 051006: P60 Observations
  4. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  5. GRB 051006: optical observations at Sierra Nevada
  6. GRB051006: Refined analysis of the Swift-BAT burst
  7. GRB051006: Swift detection of a burst
  8. GRB 050906, summary of radio observations
  9. GRB051001: Swift UVOT Upper Limits
  10. GRB 050925: Second Epoch WSRT Radio Observations
  11. GRB 051001: I-band limit
  12. GRB 051001: AAT infra-red observations
  13. GRB 051001: Swift-BAT refined analysis
  14. GRB 051001: Swift Detection of a Burst
  15. GRB 050820A: NIR photometry at the TNG
  16. GRB050925: Swift/XRT limits
  17. GRB/SGR 050925: IR Observations
  18. GRB 050922C: break in the lightcurve
  19. GRB050925: Swift UVOT upper limits
  20. Refined analysis of the Swift-BAT soft short burst
  21. GRB050925: Faulkes Telescope North R-band limit
  22. GRB050925: Swift-BAT detection of a short burst
  23. GRB050922C: TNG spectroscopic observations
  24. GRB050922B: refined XRT analysis
  25. GRB050922B: Swift UVOT early upper limits.
  26. GRB050922C: Optical Observations
  27. GRB 050922C: Swift XRT refined analysis
  28. HETE Fregate observations of GRB 050922C
  29. GRB 050922C: Swift-BAT refined analysis
  30. GRB 050922B: Swift-BAT refined analysis
  31. GRB 050922C: optical obserations
  32. GRB 050922C: NOT optical observations
  33. GRB 050922C: Swift detection of a bright burst
  34. GRB 050922B: ROTSE-III Optical Limits
  35. GRB 050922B,optical observation
  36. GRB050922B: Swift-BAT detection of a weak long burst
  37. GRB050820B: analysis of the XMM-Newton observation
  38. GRB050916: Swift/UVOT Upper Limits
  39. GRB 050916: Swift-BAT refined analysis
  40. Swift-BAT trigger 155764 is not a GRB
  41. Swift-BAT trigger 155764 is probably not a GRB
  42. Swift trigger 155764: bad XRT centroid
  43. Swift-BAT trigger 155535 is definitely not a GRB
  44. GRB050916 : Swift-XRT refined analysis
  45. GRB 050915B: Swift-BAT refined analysis
  46. GRB 050915B: Swift/UVOT Upper Limits
  47. GRB 050915a: IR Transient
  48. GRB 050915b, SMARTS optical/IR observations
  49. GRB050915B: Swift-BAT detection of a long bright burst
  50. GRB050915: Swift/UVOT upper limits
  51. GRB 050915: IR Observations
  52. GRB 050915: Swift XRT refined analysis
  53. GRB 050915: Swift-BAT refined analysis
  54. GRB 050915: Swift detection of a GRB
  55. GRB050911: Upper limit on X-ray afterglow
  56. Swift-BAT trigger 155072 ground analysis
  57. Swift-BAT trigger 155072 is probably not a GRB
  58. GRB 050908: DEIMOS spectrum and further analysis
  59. GRB 050911, optical content of Swift/XRT error box
  60. GRB 050911: Swift-BAT refined analysis
  61. GRB 050911: z~0.16 cluster in the field
  62. GRB050911: Swift-BAT detection of a long burst
  63. GRB 050910a: TAROT early optical limits
  64. WIRO observations in I of GRB 050908
  65. GRB 050906: Possible X-ray Counterpart
  66. GRB050908: Swift/UVOT Early upper limits
  67. GRB050908 : Swift-XRT refined analysis
  68. GRB 050908: Swift-BAT refined analysis
  69. GRB 050908: Optical observations
  70. GRB 050908: Optical Observations
  71. GRB 050908: Swift detection of a burst
  72. GRB 050906: Optical observations at the Very Large Telescope
  73. GRB 050904 BAT refined analysis of complete data set
  74. GRB 050904: Subaru Optical Spectroscopy
  75. GRB 050906: MARGE Optical Limits
  76. GRB 050906: Swift-BAT refined analysis
  77. GRB 050906: Swift XRT upper limit
  78. GRB 050906: Radio Observations
  79. GRB 050904: Keck I-band Imaging
  80. GRB050906: P60 Observations
  81. GRB 050904: more VLT NIR observations
  82. GRB 050904: photometric redshift
  83. GRB 050904: Swift/UVOT observations
  84. GRB 050904: NIR object inside the XRT error box
  85. GRB 050904: early Swift XRT analysis results
  86. GRB 050904: SOAR YJ and PROMPT Ic Observations
  87. GRB050904: Optical Observations
  88. GRB050904: P60 Observations
  89. GRB 050904: TAROT optical limits
  90. GRB 050827 : OSN 1.5m optical observations
  91. GRB 050827: P200 NIR Observations
  92. GRB050827: Swift/UVOT upper limits
  93. GRB 050827: Optical Limit
  94. GRB 050827: XRT possible afterglow detection
  95. GRB 050826 : Lulin R band observation
  96. GRB050824: Maidanak optical limits
  97. GRB 050827: Swift-BAT refined analysis
  98. Subaru Observations of GRB050724
  99. GRB 050826: Optical Candidate
  100. GRB 050826: Swift XRT preliminary analysis results

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