Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"
  1. GRB 111022B: MASTER-Net early limit
  2. GRB 111022A: Preliminary UVOT TDRSS Non-Detection
  3. GRB 111022A: MASTER-Net early limit
  4. GRB 111022B: Swift detection of a burst
  5. GRB 111022A: Swift detection of a burst
  6. GRB 111020A: Gemini-South additional observations and limit on an optical afterglow
  7. GRB 111020A: EVLA observations
  8. GRB 111020A: Swift-XRT refined Analysis
  9. GRB 111020A: Gemini-South i-band observations
  10. GRB 111020A: Swift/UVOT Upper Limits
  11. GRB 111020A: Faulkes Telescope South observations
  12. GRB 111020A: Swift-BAT refined analysis
  13. GRB 111020A: Enhanced Swift-XRT position
  14. GRB 111020A: BOOTES-3 Optical Upper Limit.
  15. GRB 111020A: Planned XMM-Newton observation
  16. GRB 111020A: Swift detection of a short burst
  17. GRB 111018A: Swift/UVOT Upper Limits
  18. GRB 110918A: Optical light curve for days 1.4 to 16.3
  19. GRB 111018A: Swift-BAT refined analysis
  20. Konus-Wind observation of GRB 111016B
  21. GRB 111018A: Swift-XRT refined Analysis
  22. GRB 111018A: GROND Upper Limits
  23. GRB 111018A: Enhanced Swift-XRT position
  24. IPN Triangulation of GRB 111016B (long duration, intense)
  25. GRB111016A : WIYN 3.5m NIR observations
  26. GRB 111018A: Swift detection of a burst
  27. GRB 111017A: Fermi GBM Detection
  28. GRB111016A: D50 optical limit
  29. GRB 111016A: Gemini Detection of the NIR Counterpart
  30. GRB 111016A: Swift/UVOT Detection of a Source
  31. GRB 111016A: Swift-BAT refined analysis
  32. GRB 111016A: P60 Afterglow Candidate
  33. GRB 111016A: MITSuME Akeno Optical upper limits
  34. GRB 111016A: Swift-XRT refined Analysis
  35. GRB 111016A: Enhanced Swift-XRT position
  36. GRB 111016A: Swift-XRT observations
  37. GRB 111016A: Swift detection of a burst
  38. GRB 110921A: optical observations
  39. GRB 111008A : miniTAO/ANIR NIR observations
  40. EVLA 22 GHz Detection of GRB 111008A
  41. GRB 111005A: ATCA 18 GHz decay
  42. GRB 111008A: Swift/UVOT Upper Limits
  43. Konus-Wind observation of GRB 111008A
  44. GRB 111008A: IAC80 I-band observations
  45. GRB 111008A: VLT/X-shooter spectroscopy
  46. GRB 111008A: Swift-XRT refined Analysis
  47. GRB 111008A: Gemini spectroscopic redshift
  48. GRB 111008A, GROND observations
  49. GRB 111008A: NOT optical observation
  50. GRB 111008A: Gemini optical counterpart
  51. GRB 111008A: Enhanced Swift-XRT position
  52. GRB 111008A, Swift-BAT refined analysis,
  53. GRB 111008A: Swift detection of a burst
  54. GRB 111005A: ATCA 18 GHz detection
  55. GRB 111005A: ATCA radio upper limit
  56. GRB 111005A : miniTAO/ANIR NIR observations
  57. GRB 111005A: EVLA Observations
  58. GRB 111005A: VLT optical observations
  59. GRB 111005A: GROND NIR observations
  60. GRB 111005A: VLT IR observations
  61. GRB 111005A: Swift-BAT refined analysis
  62. GRB 111005A: bright galaxy in error circle
  63. GRB 111005A: Swift detection of a burst
  64. GRB 111003A: Fermi GBM detection
  65. GRB 110905A / MAXI J1836-194: optical monitoring
  66. GRB 110921A: MITSuME-Akeno Optical photometry
  67. Skynet/Dolomiti observations of GRB 110928A
  68. Skynet observations of GRB 110928A
  69. GRB 110928A: RAPTOR Limits During Gamma-ray Emitting Interval
  70. GRB 110928A: Swift/UVOT Upper Limits
  71. Trigger 504307: Swift detection of MAXI J1836-194
  72. GRB 110928A: Swift-XRT refined Analysis
  73. GRB 110825A: GROND Observations
  74. GRB 110928A: Enhanced Swift-XRT position
  75. GRB 110928A: P60 Observations
  76. GRB 110928A: Further PAIRITEL NIR Observations
  77. GRB 110928A: Swift-BAT refined analysis
  78. GRB 110928A: Swift-XRT observations
  79. GRB 110928A: Swift/UVOT finding chart observation
  80. GRB 110928A: PAIRITEL NIR Observations
  81. GRB 110928A: ROTSE-III Optical Limits
  82. GRB 110928A: Swift detection of a burst
  83. Fermi GBM triggers 110923481, 110924391 and 110925200 are not GRBs
  84. Swift-BAT trigger 503926 is noise
  85. GRB 110924A: Swift detection of a possible burst
  86. GCN for GRB 110921B
  87. GRB 110921A: Swift/UVOT Observations
  88. GRB110918A: Lick Observations
  89. GRB 110921A: NOT observations
  90. GRB 110921A: Fermi GBM observation
  91. GRB 110921A: TNT astrometry
  92. GRB 110921A: Swift-XRT refined Analysis
  93. GRB 110921A, Swift-BAT refined analysis
  94. GRB 110918A: Liverpool Telescope optical observations
  95. GRB 110918A: submm observations from APEX
  96. GRB 110921A: optical observations in Mt. Terskol and Maidanak observatories
  97. GRB 110921A: Enhanced Swift-XRT position
  98. GRB 110921A: MITSuME Akeno Optical Observation
  99. GRB 110921A : TNT optical counterpart candidate
  100. GRB 110918A: Swift-XRT refined Analysis

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