Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

28038 results found.

  1. GRB 050922C: break in the lightcurve
  2. GRB050925: Swift UVOT upper limits
  3. Refined analysis of the Swift-BAT soft short burst
  4. GRB050925: Faulkes Telescope North R-band limit
  5. GRB050925: Swift-BAT detection of a short burst
  6. GRB050922C: TNG spectroscopic observations
  7. GRB050922B: refined XRT analysis
  8. GRB050922B: Swift UVOT early upper limits.
  9. GRB050922C: Optical Observations
  10. GRB 050922C: Swift XRT refined analysis
  11. HETE Fregate observations of GRB 050922C
  12. GRB 050922C: Swift-BAT refined analysis
  13. GRB 050922B: Swift-BAT refined analysis
  14. GRB 050922C: optical obserations
  15. GRB 050922C: NOT optical observations
  16. GRB 050922C: Swift detection of a bright burst
  17. GRB 050922B: ROTSE-III Optical Limits
  18. GRB 050922B,optical observation
  19. GRB050922B: Swift-BAT detection of a weak long burst
  20. GRB050820B: analysis of the XMM-Newton observation
  21. GRB050916: Swift/UVOT Upper Limits
  22. GRB 050916: Swift-BAT refined analysis
  23. Swift-BAT trigger 155764 is not a GRB
  24. Swift-BAT trigger 155764 is probably not a GRB
  25. Swift trigger 155764: bad XRT centroid
  26. Swift-BAT trigger 155535 is definitely not a GRB
  27. GRB050916 : Swift-XRT refined analysis
  28. GRB 050915B: Swift-BAT refined analysis
  29. GRB 050915B: Swift/UVOT Upper Limits
  30. GRB 050915a: IR Transient
  31. GRB 050915b, SMARTS optical/IR observations
  32. GRB050915B: Swift-BAT detection of a long bright burst
  33. GRB050915: Swift/UVOT upper limits
  34. GRB 050915: IR Observations
  35. GRB 050915: Swift XRT refined analysis
  36. GRB 050915: Swift-BAT refined analysis
  37. GRB 050915: Swift detection of a GRB
  38. GRB050911: Upper limit on X-ray afterglow
  39. Swift-BAT trigger 155072 ground analysis
  40. Swift-BAT trigger 155072 is probably not a GRB
  41. GRB 050908: DEIMOS spectrum and further analysis
  42. GRB 050911, optical content of Swift/XRT error box
  43. GRB 050911: Swift-BAT refined analysis
  44. GRB 050911: z~0.16 cluster in the field
  45. GRB050911: Swift-BAT detection of a long burst
  46. GRB 050910a: TAROT early optical limits
  47. WIRO observations in I of GRB 050908
  48. GRB 050906: Possible X-ray Counterpart
  49. GRB050908: Swift/UVOT Early upper limits
  50. GRB050908 : Swift-XRT refined analysis
  51. GRB 050908: Swift-BAT refined analysis
  52. GRB 050908: Optical observations
  53. GRB 050908: Optical Observations
  54. GRB 050908: Swift detection of a burst
  55. GRB 050906: Optical observations at the Very Large Telescope
  56. GRB 050904 BAT refined analysis of complete data set
  57. GRB 050904: Subaru Optical Spectroscopy
  58. GRB 050906: MARGE Optical Limits
  59. GRB 050906: Swift-BAT refined analysis
  60. GRB 050906: Swift XRT upper limit
  61. GRB 050906: Radio Observations
  62. GRB 050904: Keck I-band Imaging
  63. GRB050906: P60 Observations
  64. GRB 050904: more VLT NIR observations
  65. GRB 050904: photometric redshift
  66. GRB 050904: Swift/UVOT observations
  67. GRB 050904: NIR object inside the XRT error box
  68. GRB 050904: early Swift XRT analysis results
  69. GRB 050904: SOAR YJ and PROMPT Ic Observations
  70. GRB050904: Optical Observations
  71. GRB050904: P60 Observations
  72. GRB 050904: TAROT optical limits
  73. GRB 050827 : OSN 1.5m optical observations
  74. GRB 050827: P200 NIR Observations
  75. GRB050827: Swift/UVOT upper limits
  76. GRB 050827: Optical Limit
  77. GRB 050827: XRT possible afterglow detection
  78. GRB 050826 : Lulin R band observation
  79. GRB050824: Maidanak optical limits
  80. GRB 050827: Swift-BAT refined analysis
  81. Subaru Observations of GRB050724
  82. GRB 050826: Optical Candidate
  83. GRB 050826: Swift XRT preliminary analysis results
  84. GRB 050826: BAT refined analysis
  85. GRB050826: Swift/UVOT early upper limits
  86. GRB050826: Swift-BAT detection of a long burst
  87. GRB050824: MASTER final analysis of the OT observations
  88. Swift-BAT trigger 152038 is probably not a GRB
  89. GRB 050824: XRT refined analysis and possible afterglow detection
  90. GRB 050824: BAT refined analysis of a soft weak burst
  91. GRB050824: MASTER:OT decay
  92. GRB050824: MASTER observation OT
  93. GRB050805a: MASTER optical candidat
  94. XRF050509c: Radio upper limits from GMRT
  95. GRB050822: Swift/UVOT upper limits
  96. GRB 050820A BAT observations of second, larger episode of emission
  97. GRB050813: Maidanak I-band observations
  98. GRB 050822: Swift-BAT refined analysis
  99. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  100. GRB050820B at FRAM

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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