Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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"
  1. GRB 051117B: Optical observations
  2. GRB 051117B: ROTSE-III Optical Limits
  3. GRB051117B: Swift XRT position
  4. GRB 051117B: Swift detection of a burst
  5. GRB 051117: Swift detection of a bright burst
  6. GRB051114: results of the Swift-XRT observation
  7. GRB 051028 Optical Observations
  8. GRB 051109B : Nainital upper limits
  9. GRB 051114: Radio Observations
  10. GRB 051114: Swift-BAT refined analysis
  11. GRB050925: analysis of the XMM-Newton observation
  12. GRB051109A optical observations
  13. GRB 051114: Swift-BAT detection of a short burst
  14. GRB 051111: Further spectroscopic analysis
  15. GRB 051111: Radio afterglow
  16. GRB 051113: Swift-BAT refined analysis
  17. GRB 051113: Swift-BAT detection of a burst
  18. GRB 051111: AEOS optical observations
  19. GRB051103: Radio Observations
  20. GRB 051109A Milagro GeV/TeV Observations
  21. GRB/SGR 050925: XMM-Newton ToO observation
  22. GRB051111: Swift/UVOT Observations
  23. GRB 051111A : R-band temporal decay index based on Lulin
  24. GRB051111: XRT preliminary analysis
  25. GRB 051111: Swift-BAT refined analysis
  26. GRB 051109A Optical Observations
  27. GRB 051111A : Lulin BVRI multi band afterglow observation
  28. GRB051111a: SARA Observations
  29. GRB 051111a: IR photometry
  30. GRB 051111: Keck HIRES redshift
  31. GRB 051111A: KAIT optical observations
  32. GRB 051111a: Afterglow fading in Ic
  33. GRB051111: Super-LOTIS Early Detection
  34. GRB 051111: ROTSE-III Analysis of Prompt Counterpart
  35. Faulkes Telescope R-band detection of GRB051111
  36. GRB 051103 Milagro GeV/TeV Observations
  37. GRB051111: Swift-BAT detection of a bright burst
  38. GRB 051111A: ROTSE-III Detection of Possible Counterpart
  39. GRB 051008 Tautenburg Supernova Search
  40. GRB 051109B. Radio Observations
  41. GRB 051109A
  42. GRB051109A - radio observations
  43. GRB 051105a: GETS optical limit
  44. GRB 051109b: GETS observation
  45. GRB 051109A: KAIT optical observations
  46. Early RAPTOR measurements of GRB 051109a - the movie.
  47. Konus-Wind observation of GRB 051109A
  48. GRB 051109B: Swift-BAT refined analysis
  49. GRB 051109B: ROTSE-III Optical Limits
  50. GRB 051109A: Swift-UVOT Observations
  51. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  52. GRB051109B: no UVOT source detected
  53. GRB051109B: XRT refined analysis
  54. GRB 051109B : Lulin Optical Observations
  55. GRB 051109A : Lulin BVRI Optical afterglow observation
  56. GRB051109A: further steepening in the X-ray light curve
  57. GRB051109A: XRT refined analysis
  58. GRB 051109a: BOOTES R & I-band detection of the early afterglow
  59. GRB051109B: XRT position
  60. GRB 051109B: Super-LOTIS Observations
  61. GRB 051109B Kiso optical follow-up observation
  62. GRB051105B: REM Optical observation
  63. GRB 051109B: Swift detection of a burst
  64. GRB 051109: HET Optical Spectrum and Absorption Redshift
  65. GRB 051109: PROMPT Detections
  66. GRB 051109: Rc and Ic observations
  67. GRB051109: Early Super-LOTIS Detection
  68. GRB 051109: Swift-BAT refined analysis
  69. GRB 051109a: IR Photometry and Astrometry
  70. GRB 051109a: MDM Observations
  71. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  72. GRB051109: Swift detection of a burst
  73. GRB 051109a: IR Detections
  74. GRB 051109: ROTSE-III Detection of Possible Counterpart
  75. GRB051105B: Swift/XRT upper limit
  76. GRB051105B: Swift/UVOT upper limit
  77. GRB051103: optical observations
  78. GRB 051103, optical observations
  79. GRB051103: MASTER: OT limit and host galaxy candidates
  80. GRB051028: Swift-XRT refined analysis
  81. GRB 051105a, observation from Naini Tal and OSN
  82. GRB 051105A, 2nd epoch optical observations
  83. GRB 051105a: MDM Observations
  84. GRB 051105A: TNG optical observations
  85. GRB051105A: Swift/UVOT Observations
  86. GRB 051105A, radio observations
  87. GRB051103:_MASTER_optical_observations
  88. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  89. GRB 051105A, optical observations
  90. XRT observations of GRB 051105A
  91. GRB 051105: Swift-BAT improved refined analysis
  92. GRB 051105b: ART optical limits
  93. GRB051105B - A long GRB detected by INTEGRAL
  94. GRB 051105B (INTEGRAL 2701): Optical observation
  95. GRB 051105: Swift-BAT refined analysis
  96. GRB 051105: Optical limit
  97. GRB 051105: Swift detection of a short burst
  98. IBAS Alert 2700: Not a GRB
  99. GRB 051016B host spectroscopy and redshift
  100. GRB051016B: optical observation

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