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"

26335 results found.

  1. GRB050925: Faulkes Telescope North R-band limit
  2. GRB050925: Swift-BAT detection of a short burst
  3. GRB050922C: TNG spectroscopic observations
  4. GRB050922B: refined XRT analysis
  5. GRB050922B: Swift UVOT early upper limits.
  6. GRB050922C: Optical Observations
  7. GRB 050922C: Swift XRT refined analysis
  8. HETE Fregate observations of GRB 050922C
  9. GRB 050922C: Swift-BAT refined analysis
  10. GRB 050922B: Swift-BAT refined analysis
  11. GRB 050922C: optical obserations
  12. GRB 050922C: NOT optical observations
  13. GRB 050922C: Swift detection of a bright burst
  14. GRB 050922B: ROTSE-III Optical Limits
  15. GRB 050922B,optical observation
  16. GRB050922B: Swift-BAT detection of a weak long burst
  17. GRB050820B: analysis of the XMM-Newton observation
  18. GRB050916: Swift/UVOT Upper Limits
  19. GRB 050916: Swift-BAT refined analysis
  20. Swift-BAT trigger 155764 is not a GRB
  21. Swift-BAT trigger 155764 is probably not a GRB
  22. Swift trigger 155764: bad XRT centroid
  23. Swift-BAT trigger 155535 is definitely not a GRB
  24. GRB050916 : Swift-XRT refined analysis
  25. GRB 050915B: Swift-BAT refined analysis
  26. GRB 050915B: Swift/UVOT Upper Limits
  27. GRB 050915a: IR Transient
  28. GRB 050915b, SMARTS optical/IR observations
  29. GRB050915B: Swift-BAT detection of a long bright burst
  30. GRB050915: Swift/UVOT upper limits
  31. GRB 050915: IR Observations
  32. GRB 050915: Swift XRT refined analysis
  33. GRB 050915: Swift-BAT refined analysis
  34. GRB 050915: Swift detection of a GRB
  35. GRB050911: Upper limit on X-ray afterglow
  36. Swift-BAT trigger 155072 ground analysis
  37. Swift-BAT trigger 155072 is probably not a GRB
  38. GRB 050908: DEIMOS spectrum and further analysis
  39. GRB 050911, optical content of Swift/XRT error box
  40. GRB 050911: Swift-BAT refined analysis
  41. GRB 050911: z~0.16 cluster in the field
  42. GRB050911: Swift-BAT detection of a long burst
  43. GRB 050910a: TAROT early optical limits
  44. WIRO observations in I of GRB 050908
  45. GRB 050906: Possible X-ray Counterpart
  46. GRB050908: Swift/UVOT Early upper limits
  47. GRB050908 : Swift-XRT refined analysis
  48. GRB 050908: Swift-BAT refined analysis
  49. GRB 050908: Optical observations
  50. GRB 050908: Optical Observations
  51. GRB 050908: Swift detection of a burst
  52. GRB 050906: Optical observations at the Very Large Telescope
  53. GRB 050904 BAT refined analysis of complete data set
  54. GRB 050904: Subaru Optical Spectroscopy
  55. GRB 050906: MARGE Optical Limits
  56. GRB 050906: Swift-BAT refined analysis
  57. GRB 050906: Swift XRT upper limit
  58. GRB 050906: Radio Observations
  59. GRB 050904: Keck I-band Imaging
  60. GRB050906: P60 Observations
  61. GRB 050904: more VLT NIR observations
  62. GRB 050904: photometric redshift
  63. GRB 050904: Swift/UVOT observations
  64. GRB 050904: NIR object inside the XRT error box
  65. GRB 050904: early Swift XRT analysis results
  66. GRB 050904: SOAR YJ and PROMPT Ic Observations
  67. GRB050904: Optical Observations
  68. GRB050904: P60 Observations
  69. GRB 050904: TAROT optical limits
  70. GRB 050827 : OSN 1.5m optical observations
  71. GRB 050827: P200 NIR Observations
  72. GRB050827: Swift/UVOT upper limits
  73. GRB 050827: Optical Limit
  74. GRB 050827: XRT possible afterglow detection
  75. GRB 050826 : Lulin R band observation
  76. GRB050824: Maidanak optical limits
  77. GRB 050827: Swift-BAT refined analysis
  78. Subaru Observations of GRB050724
  79. GRB 050826: Optical Candidate
  80. GRB 050826: Swift XRT preliminary analysis results
  81. GRB 050826: BAT refined analysis
  82. GRB050826: Swift/UVOT early upper limits
  83. GRB050826: Swift-BAT detection of a long burst
  84. GRB050824: MASTER final analysis of the OT observations
  85. Swift-BAT trigger 152038 is probably not a GRB
  86. GRB 050824: XRT refined analysis and possible afterglow detection
  87. GRB 050824: BAT refined analysis of a soft weak burst
  88. GRB050824: MASTER:OT decay
  89. GRB050824: MASTER observation OT
  90. GRB050805a: MASTER optical candidat
  91. XRF050509c: Radio upper limits from GMRT
  92. GRB050822: Swift/UVOT upper limits
  93. GRB 050820A BAT observations of second, larger episode of emission
  94. GRB050813: Maidanak I-band observations
  95. GRB 050822: Swift-BAT refined analysis
  96. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  97. GRB050820B at FRAM
  98. Swift/UVOT UV Photometry of GRB 050820B
  99. GRB 050822: Swift detection of a long burst
  100. GRB050820a BVRcIc field photometry

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