Skip to main content
GCN at AAS 245, Legacy Circulars Address Retirement. 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').
  1. GRB 051210: Swift XRT refined analysis
  2. GRB 051210: FRAM early limit
  3. GRB 051210: Swift-BAT refined analysis of a short burst
  4. GRB051210: Swift UVOT Observation
  5. GRB 051210: A short GRB in a cluster?
  6. GRB 051210: Swift detection of a burst
  7. IPN observations of SGR1806-20
  8. Swift XRT positions
  9. An extraordinary long burst on December 3 from SGR1806-20
  10. IBAS Alert 2706 : not a real GRB
  11. Possible resuming of the SGR 1806-20 activity
  12. Swift UVOT Calibration Documentation
  13. GRB051117B: optical observation
  14. GRB051111: optical observaion
  15. Swift-BAT trigger 165579 is not a GRB
  16. GRB 051127: Swift-BAT detection of a possible burst
  17. GRB051117B: Swift XRT refined analysis
  18. GRB051117b: No Swift/UVOT Detection
  19. GRB051111: Rc optical observations: correction
  20. GRB 051117A: Swift/UVOT Detection of an Afterglow: Correction
  21. GRB 051117A: Swift/UVOT Detection of an Afterglow
  22. GRB051111: Suzaku WAM observation of the prompt emission
  23. GRB051111: Rc optical observations
  24. GRB051008: Suzaku WAM observation of the prompt emission
  25. GRB 051109B: GAO 150cm telescope Optical limit
  26. GRB 051109A : GAO 150cm telescope Rc-band detection
  27. GRB 051021 Optical Observations
  28. GRB 051117B: MARGE Optical Limits
  29. GRB 051117A and B: Radio Observations
  30. GRB 051117B: R and I observations of possible host galaxy
  31. GRB 051117b: NIR observations
  32. GRB 051117A: Refined analysis of the Swift-BAT burst
  33. GRB 051117B: Refined analysis of the Swift-BAT burst
  34. GRB051117A : XRT refined analysis
  35. GRB 051117B,optical observation
  36. GRB 051117B: Lulin R and I band observation
  37. GRB 051117B: Optical observations
  38. GRB 051117B: ROTSE-III Optical Limits
  39. GRB051117B: Swift XRT position
  40. GRB 051117B: Swift detection of a burst
  41. GRB 051117: Swift detection of a bright burst
  42. GRB051114: results of the Swift-XRT observation
  43. GRB 051028 Optical Observations
  44. GRB 051109B : Nainital upper limits
  45. GRB 051114: Radio Observations
  46. GRB 051114: Swift-BAT refined analysis
  47. GRB050925: analysis of the XMM-Newton observation
  48. GRB051109A optical observations
  49. GRB 051114: Swift-BAT detection of a short burst
  50. GRB 051111: Further spectroscopic analysis
  51. GRB 051111: Radio afterglow
  52. GRB 051113: Swift-BAT refined analysis
  53. GRB 051113: Swift-BAT detection of a burst
  54. GRB 051111: AEOS optical observations
  55. GRB051103: Radio Observations
  56. GRB 051109A Milagro GeV/TeV Observations
  57. GRB/SGR 050925: XMM-Newton ToO observation
  58. GRB051111: Swift/UVOT Observations
  59. GRB 051111A : R-band temporal decay index based on Lulin
  60. GRB051111: XRT preliminary analysis
  61. GRB 051111: Swift-BAT refined analysis
  62. GRB 051109A Optical Observations
  63. GRB 051111A : Lulin BVRI multi band afterglow observation
  64. GRB051111a: SARA Observations
  65. GRB 051111a: IR photometry
  66. GRB 051111: Keck HIRES redshift
  67. GRB 051111A: KAIT optical observations
  68. GRB 051111a: Afterglow fading in Ic
  69. GRB051111: Super-LOTIS Early Detection
  70. GRB 051111: ROTSE-III Analysis of Prompt Counterpart
  71. Faulkes Telescope R-band detection of GRB051111
  72. GRB 051103 Milagro GeV/TeV Observations
  73. GRB051111: Swift-BAT detection of a bright burst
  74. GRB 051111A: ROTSE-III Detection of Possible Counterpart
  75. GRB 051008 Tautenburg Supernova Search
  76. GRB 051109B. Radio Observations
  77. GRB 051109A
  78. GRB051109A - radio observations
  79. GRB 051105a: GETS optical limit
  80. GRB 051109b: GETS observation
  81. GRB 051109A: KAIT optical observations
  82. Early RAPTOR measurements of GRB 051109a - the movie.
  83. Konus-Wind observation of GRB 051109A
  84. GRB 051109B: Swift-BAT refined analysis
  85. GRB 051109B: ROTSE-III Optical Limits
  86. GRB 051109A: Swift-UVOT Observations
  87. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  88. GRB051109B: no UVOT source detected
  89. GRB051109B: XRT refined analysis
  90. GRB 051109B : Lulin Optical Observations
  91. GRB 051109A : Lulin BVRI Optical afterglow observation
  92. GRB051109A: further steepening in the X-ray light curve
  93. GRB051109A: XRT refined analysis
  94. GRB 051109a: BOOTES R & I-band detection of the early afterglow
  95. GRB051109B: XRT position
  96. GRB 051109B: Super-LOTIS Observations
  97. GRB 051109B Kiso optical follow-up observation
  98. GRB051105B: REM Optical observation
  99. GRB 051109B: Swift detection of a burst
  100. GRB 051109: HET Optical Spectrum and Absorption Redshift

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