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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').
  1. GRB 051127: Swift-BAT detection of a possible burst
  2. GRB051117B: Swift XRT refined analysis
  3. GRB051117b: No Swift/UVOT Detection
  4. GRB051111: Rc optical observations: correction
  5. GRB 051117A: Swift/UVOT Detection of an Afterglow: Correction
  6. GRB 051117A: Swift/UVOT Detection of an Afterglow
  7. GRB051111: Suzaku WAM observation of the prompt emission
  8. GRB051111: Rc optical observations
  9. GRB051008: Suzaku WAM observation of the prompt emission
  10. GRB 051109B: GAO 150cm telescope Optical limit
  11. GRB 051109A : GAO 150cm telescope Rc-band detection
  12. GRB 051021 Optical Observations
  13. GRB 051117B: MARGE Optical Limits
  14. GRB 051117A and B: Radio Observations
  15. GRB 051117B: R and I observations of possible host galaxy
  16. GRB 051117b: NIR observations
  17. GRB 051117A: Refined analysis of the Swift-BAT burst
  18. GRB 051117B: Refined analysis of the Swift-BAT burst
  19. GRB051117A : XRT refined analysis
  20. GRB 051117B,optical observation
  21. GRB 051117B: Lulin R and I band observation
  22. GRB 051117B: Optical observations
  23. GRB 051117B: ROTSE-III Optical Limits
  24. GRB051117B: Swift XRT position
  25. GRB 051117B: Swift detection of a burst
  26. GRB 051117: Swift detection of a bright burst
  27. GRB051114: results of the Swift-XRT observation
  28. GRB 051028 Optical Observations
  29. GRB 051109B : Nainital upper limits
  30. GRB 051114: Radio Observations
  31. GRB 051114: Swift-BAT refined analysis
  32. GRB050925: analysis of the XMM-Newton observation
  33. GRB051109A optical observations
  34. GRB 051114: Swift-BAT detection of a short burst
  35. GRB 051111: Further spectroscopic analysis
  36. GRB 051111: Radio afterglow
  37. GRB 051113: Swift-BAT refined analysis
  38. GRB 051113: Swift-BAT detection of a burst
  39. GRB 051111: AEOS optical observations
  40. GRB051103: Radio Observations
  41. GRB 051109A Milagro GeV/TeV Observations
  42. GRB/SGR 050925: XMM-Newton ToO observation
  43. GRB051111: Swift/UVOT Observations
  44. GRB 051111A : R-band temporal decay index based on Lulin
  45. GRB051111: XRT preliminary analysis
  46. GRB 051111: Swift-BAT refined analysis
  47. GRB 051109A Optical Observations
  48. GRB 051111A : Lulin BVRI multi band afterglow observation
  49. GRB051111a: SARA Observations
  50. GRB 051111a: IR photometry
  51. GRB 051111: Keck HIRES redshift
  52. GRB 051111A: KAIT optical observations
  53. GRB 051111a: Afterglow fading in Ic
  54. GRB051111: Super-LOTIS Early Detection
  55. GRB 051111: ROTSE-III Analysis of Prompt Counterpart
  56. Faulkes Telescope R-band detection of GRB051111
  57. GRB 051103 Milagro GeV/TeV Observations
  58. GRB051111: Swift-BAT detection of a bright burst
  59. GRB 051111A: ROTSE-III Detection of Possible Counterpart
  60. GRB 051008 Tautenburg Supernova Search
  61. GRB 051109B. Radio Observations
  62. GRB 051109A
  63. GRB051109A - radio observations
  64. GRB 051105a: GETS optical limit
  65. GRB 051109b: GETS observation
  66. GRB 051109A: KAIT optical observations
  67. Early RAPTOR measurements of GRB 051109a - the movie.
  68. Konus-Wind observation of GRB 051109A
  69. GRB 051109B: Swift-BAT refined analysis
  70. GRB 051109B: ROTSE-III Optical Limits
  71. GRB 051109A: Swift-UVOT Observations
  72. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  73. GRB051109B: no UVOT source detected
  74. GRB051109B: XRT refined analysis
  75. GRB 051109B : Lulin Optical Observations
  76. GRB 051109A : Lulin BVRI Optical afterglow observation
  77. GRB051109A: further steepening in the X-ray light curve
  78. GRB051109A: XRT refined analysis
  79. GRB 051109a: BOOTES R & I-band detection of the early afterglow
  80. GRB051109B: XRT position
  81. GRB 051109B: Super-LOTIS Observations
  82. GRB 051109B Kiso optical follow-up observation
  83. GRB051105B: REM Optical observation
  84. GRB 051109B: Swift detection of a burst
  85. GRB 051109: HET Optical Spectrum and Absorption Redshift
  86. GRB 051109: PROMPT Detections
  87. GRB 051109: Rc and Ic observations
  88. GRB051109: Early Super-LOTIS Detection
  89. GRB 051109: Swift-BAT refined analysis
  90. GRB 051109a: IR Photometry and Astrometry
  91. GRB 051109a: MDM Observations
  92. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  93. GRB051109: Swift detection of a burst
  94. GRB 051109a: IR Detections
  95. GRB 051109: ROTSE-III Detection of Possible Counterpart
  96. GRB051105B: Swift/XRT upper limit
  97. GRB051105B: Swift/UVOT upper limit
  98. GRB051103: optical observations
  99. GRB 051103, optical observations
  100. GRB051103: MASTER: OT limit and host galaxy candidates

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