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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 051109B : Nainital upper limits
  2. GRB 051114: Radio Observations
  3. GRB 051114: Swift-BAT refined analysis
  4. GRB050925: analysis of the XMM-Newton observation
  5. GRB051109A optical observations
  6. GRB 051114: Swift-BAT detection of a short burst
  7. GRB 051111: Further spectroscopic analysis
  8. GRB 051111: Radio afterglow
  9. GRB 051113: Swift-BAT refined analysis
  10. GRB 051113: Swift-BAT detection of a burst
  11. GRB 051111: AEOS optical observations
  12. GRB051103: Radio Observations
  13. GRB 051109A Milagro GeV/TeV Observations
  14. GRB/SGR 050925: XMM-Newton ToO observation
  15. GRB051111: Swift/UVOT Observations
  16. GRB 051111A : R-band temporal decay index based on Lulin
  17. GRB051111: XRT preliminary analysis
  18. GRB 051111: Swift-BAT refined analysis
  19. GRB 051109A Optical Observations
  20. GRB 051111A : Lulin BVRI multi band afterglow observation
  21. GRB051111a: SARA Observations
  22. GRB 051111a: IR photometry
  23. GRB 051111: Keck HIRES redshift
  24. GRB 051111A: KAIT optical observations
  25. GRB 051111a: Afterglow fading in Ic
  26. GRB051111: Super-LOTIS Early Detection
  27. GRB 051111: ROTSE-III Analysis of Prompt Counterpart
  28. Faulkes Telescope R-band detection of GRB051111
  29. GRB 051103 Milagro GeV/TeV Observations
  30. GRB051111: Swift-BAT detection of a bright burst
  31. GRB 051111A: ROTSE-III Detection of Possible Counterpart
  32. GRB 051008 Tautenburg Supernova Search
  33. GRB 051109B. Radio Observations
  34. GRB 051109A
  35. GRB051109A - radio observations
  36. GRB 051105a: GETS optical limit
  37. GRB 051109b: GETS observation
  38. GRB 051109A: KAIT optical observations
  39. Early RAPTOR measurements of GRB 051109a - the movie.
  40. Konus-Wind observation of GRB 051109A
  41. GRB 051109B: Swift-BAT refined analysis
  42. GRB 051109B: ROTSE-III Optical Limits
  43. GRB 051109A: Swift-UVOT Observations
  44. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  45. GRB051109B: no UVOT source detected
  46. GRB051109B: XRT refined analysis
  47. GRB 051109B : Lulin Optical Observations
  48. GRB 051109A : Lulin BVRI Optical afterglow observation
  49. GRB051109A: further steepening in the X-ray light curve
  50. GRB051109A: XRT refined analysis
  51. GRB 051109a: BOOTES R & I-band detection of the early afterglow
  52. GRB051109B: XRT position
  53. GRB 051109B: Super-LOTIS Observations
  54. GRB 051109B Kiso optical follow-up observation
  55. GRB051105B: REM Optical observation
  56. GRB 051109B: Swift detection of a burst
  57. GRB 051109: HET Optical Spectrum and Absorption Redshift
  58. GRB 051109: PROMPT Detections
  59. GRB 051109: Rc and Ic observations
  60. GRB051109: Early Super-LOTIS Detection
  61. GRB 051109: Swift-BAT refined analysis
  62. GRB 051109a: IR Photometry and Astrometry
  63. GRB 051109a: MDM Observations
  64. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  65. GRB051109: Swift detection of a burst
  66. GRB 051109a: IR Detections
  67. GRB 051109: ROTSE-III Detection of Possible Counterpart
  68. GRB051105B: Swift/XRT upper limit
  69. GRB051105B: Swift/UVOT upper limit
  70. GRB051103: optical observations
  71. GRB 051103, optical observations
  72. GRB051103: MASTER: OT limit and host galaxy candidates
  73. GRB051028: Swift-XRT refined analysis
  74. GRB 051105a, observation from Naini Tal and OSN
  75. GRB 051105A, 2nd epoch optical observations
  76. GRB 051105a: MDM Observations
  77. GRB 051105A: TNG optical observations
  78. GRB051105A: Swift/UVOT Observations
  79. GRB 051105A, radio observations
  80. GRB051103:_MASTER_optical_observations
  81. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  82. GRB 051105A, optical observations
  83. XRT observations of GRB 051105A
  84. GRB 051105: Swift-BAT improved refined analysis
  85. GRB 051105b: ART optical limits
  86. GRB051105B - A long GRB detected by INTEGRAL
  87. GRB 051105B (INTEGRAL 2701): Optical observation
  88. GRB 051105: Swift-BAT refined analysis
  89. GRB 051105: Optical limit
  90. GRB 051105: Swift detection of a short burst
  91. IBAS Alert 2700: Not a GRB
  92. GRB 051016B host spectroscopy and redshift
  93. GRB051016B: optical observation
  94. Recent GRB UBVRcIc field photometry
  95. Konus-Wind observation of GRB 051028
  96. GRB051028:MASTER correction and final results
  97. GRB 051022: RTT150 optical observations
  98. GRB 051021A: RTT150 optical observations
  99. GRB051028 SARA Observation
  100. GRB051028: optical observations

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