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"

26327 results found.

  1. GRB 050922C: Swift-BAT refined analysis
  2. GRB 050922B: Swift-BAT refined analysis
  3. GRB 050922C: optical obserations
  4. GRB 050922C: NOT optical observations
  5. GRB 050922C: Swift detection of a bright burst
  6. GRB 050922B: ROTSE-III Optical Limits
  7. GRB 050922B,optical observation
  8. GRB050922B: Swift-BAT detection of a weak long burst
  9. GRB050820B: analysis of the XMM-Newton observation
  10. GRB050916: Swift/UVOT Upper Limits
  11. GRB 050916: Swift-BAT refined analysis
  12. Swift-BAT trigger 155764 is not a GRB
  13. Swift-BAT trigger 155764 is probably not a GRB
  14. Swift trigger 155764: bad XRT centroid
  15. Swift-BAT trigger 155535 is definitely not a GRB
  16. GRB050916 : Swift-XRT refined analysis
  17. GRB 050915B: Swift-BAT refined analysis
  18. GRB 050915B: Swift/UVOT Upper Limits
  19. GRB 050915a: IR Transient
  20. GRB 050915b, SMARTS optical/IR observations
  21. GRB050915B: Swift-BAT detection of a long bright burst
  22. GRB050915: Swift/UVOT upper limits
  23. GRB 050915: IR Observations
  24. GRB 050915: Swift XRT refined analysis
  25. GRB 050915: Swift-BAT refined analysis
  26. GRB 050915: Swift detection of a GRB
  27. GRB050911: Upper limit on X-ray afterglow
  28. Swift-BAT trigger 155072 ground analysis
  29. Swift-BAT trigger 155072 is probably not a GRB
  30. GRB 050908: DEIMOS spectrum and further analysis
  31. GRB 050911, optical content of Swift/XRT error box
  32. GRB 050911: Swift-BAT refined analysis
  33. GRB 050911: z~0.16 cluster in the field
  34. GRB050911: Swift-BAT detection of a long burst
  35. GRB 050910a: TAROT early optical limits
  36. WIRO observations in I of GRB 050908
  37. GRB 050906: Possible X-ray Counterpart
  38. GRB050908: Swift/UVOT Early upper limits
  39. GRB050908 : Swift-XRT refined analysis
  40. GRB 050908: Swift-BAT refined analysis
  41. GRB 050908: Optical observations
  42. GRB 050908: Optical Observations
  43. GRB 050908: Swift detection of a burst
  44. GRB 050906: Optical observations at the Very Large Telescope
  45. GRB 050904 BAT refined analysis of complete data set
  46. GRB 050904: Subaru Optical Spectroscopy
  47. GRB 050906: MARGE Optical Limits
  48. GRB 050906: Swift-BAT refined analysis
  49. GRB 050906: Swift XRT upper limit
  50. GRB 050906: Radio Observations
  51. GRB 050904: Keck I-band Imaging
  52. GRB050906: P60 Observations
  53. GRB 050904: more VLT NIR observations
  54. GRB 050904: photometric redshift
  55. GRB 050904: Swift/UVOT observations
  56. GRB 050904: NIR object inside the XRT error box
  57. GRB 050904: early Swift XRT analysis results
  58. GRB 050904: SOAR YJ and PROMPT Ic Observations
  59. GRB050904: Optical Observations
  60. GRB050904: P60 Observations
  61. GRB 050904: TAROT optical limits
  62. GRB 050827 : OSN 1.5m optical observations
  63. GRB 050827: P200 NIR Observations
  64. GRB050827: Swift/UVOT upper limits
  65. GRB 050827: Optical Limit
  66. GRB 050827: XRT possible afterglow detection
  67. GRB 050826 : Lulin R band observation
  68. GRB050824: Maidanak optical limits
  69. GRB 050827: Swift-BAT refined analysis
  70. Subaru Observations of GRB050724
  71. GRB 050826: Optical Candidate
  72. GRB 050826: Swift XRT preliminary analysis results
  73. GRB 050826: BAT refined analysis
  74. GRB050826: Swift/UVOT early upper limits
  75. GRB050826: Swift-BAT detection of a long burst
  76. GRB050824: MASTER final analysis of the OT observations
  77. Swift-BAT trigger 152038 is probably not a GRB
  78. GRB 050824: XRT refined analysis and possible afterglow detection
  79. GRB 050824: BAT refined analysis of a soft weak burst
  80. GRB050824: MASTER:OT decay
  81. GRB050824: MASTER observation OT
  82. GRB050805a: MASTER optical candidat
  83. XRF050509c: Radio upper limits from GMRT
  84. GRB050822: Swift/UVOT upper limits
  85. GRB 050820A BAT observations of second, larger episode of emission
  86. GRB050813: Maidanak I-band observations
  87. GRB 050822: Swift-BAT refined analysis
  88. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  89. GRB050820B at FRAM
  90. Swift/UVOT UV Photometry of GRB 050820B
  91. GRB 050822: Swift detection of a long burst
  92. GRB050820a BVRcIc field photometry
  93. GRB050820B XMM-Newton observation
  94. GRB 050820a: NIR Observations by WIRO
  95. GRB 050820B: Swift XRT position
  96. GRB050820B: Refined analysis of the Swift-BAT burst
  97. GRB050820: refined XRT analysis
  98. GRB 050820 Swift-BAT refined analysis
  99. GRB050819: refined XRT analysis
  100. GRB 050820: Swift detection of a GRB

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