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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. GRB051111: Rc optical observations
  2. GRB051008: Suzaku WAM observation of the prompt emission
  3. GRB 051109B: GAO 150cm telescope Optical limit
  4. GRB 051109A : GAO 150cm telescope Rc-band detection
  5. GRB 051021 Optical Observations
  6. GRB 051117B: MARGE Optical Limits
  7. GRB 051117A and B: Radio Observations
  8. GRB 051117B: R and I observations of possible host galaxy
  9. GRB 051117b: NIR observations
  10. GRB 051117A: Refined analysis of the Swift-BAT burst
  11. GRB 051117B: Refined analysis of the Swift-BAT burst
  12. GRB051117A : XRT refined analysis
  13. GRB 051117B,optical observation
  14. GRB 051117B: Lulin R and I band observation
  15. GRB 051117B: Optical observations
  16. GRB 051117B: ROTSE-III Optical Limits
  17. GRB051117B: Swift XRT position
  18. GRB 051117B: Swift detection of a burst
  19. GRB 051117: Swift detection of a bright burst
  20. GRB051114: results of the Swift-XRT observation
  21. GRB 051028 Optical Observations
  22. GRB 051109B : Nainital upper limits
  23. GRB 051114: Radio Observations
  24. GRB 051114: Swift-BAT refined analysis
  25. GRB050925: analysis of the XMM-Newton observation
  26. GRB051109A optical observations
  27. GRB 051114: Swift-BAT detection of a short burst
  28. GRB 051111: Further spectroscopic analysis
  29. GRB 051111: Radio afterglow
  30. GRB 051113: Swift-BAT refined analysis
  31. GRB 051113: Swift-BAT detection of a burst
  32. GRB 051111: AEOS optical observations
  33. GRB051103: Radio Observations
  34. GRB 051109A Milagro GeV/TeV Observations
  35. GRB/SGR 050925: XMM-Newton ToO observation
  36. GRB051111: Swift/UVOT Observations
  37. GRB 051111A : R-band temporal decay index based on Lulin
  38. GRB051111: XRT preliminary analysis
  39. GRB 051111: Swift-BAT refined analysis
  40. GRB 051109A Optical Observations
  41. GRB 051111A : Lulin BVRI multi band afterglow observation
  42. GRB051111a: SARA Observations
  43. GRB 051111a: IR photometry
  44. GRB 051111: Keck HIRES redshift
  45. GRB 051111A: KAIT optical observations
  46. GRB 051111a: Afterglow fading in Ic
  47. GRB051111: Super-LOTIS Early Detection
  48. GRB 051111: ROTSE-III Analysis of Prompt Counterpart
  49. Faulkes Telescope R-band detection of GRB051111
  50. GRB 051103 Milagro GeV/TeV Observations
  51. GRB051111: Swift-BAT detection of a bright burst
  52. GRB 051111A: ROTSE-III Detection of Possible Counterpart
  53. GRB 051008 Tautenburg Supernova Search
  54. GRB 051109B. Radio Observations
  55. GRB 051109A
  56. GRB051109A - radio observations
  57. GRB 051105a: GETS optical limit
  58. GRB 051109b: GETS observation
  59. GRB 051109A: KAIT optical observations
  60. Early RAPTOR measurements of GRB 051109a - the movie.
  61. Konus-Wind observation of GRB 051109A
  62. GRB 051109B: Swift-BAT refined analysis
  63. GRB 051109B: ROTSE-III Optical Limits
  64. GRB 051109A: Swift-UVOT Observations
  65. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  66. GRB051109B: no UVOT source detected
  67. GRB051109B: XRT refined analysis
  68. GRB 051109B : Lulin Optical Observations
  69. GRB 051109A : Lulin BVRI Optical afterglow observation
  70. GRB051109A: further steepening in the X-ray light curve
  71. GRB051109A: XRT refined analysis
  72. GRB 051109a: BOOTES R & I-band detection of the early afterglow
  73. GRB051109B: XRT position
  74. GRB 051109B: Super-LOTIS Observations
  75. GRB 051109B Kiso optical follow-up observation
  76. GRB051105B: REM Optical observation
  77. GRB 051109B: Swift detection of a burst
  78. GRB 051109: HET Optical Spectrum and Absorption Redshift
  79. GRB 051109: PROMPT Detections
  80. GRB 051109: Rc and Ic observations
  81. GRB051109: Early Super-LOTIS Detection
  82. GRB 051109: Swift-BAT refined analysis
  83. GRB 051109a: IR Photometry and Astrometry
  84. GRB 051109a: MDM Observations
  85. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  86. GRB051109: Swift detection of a burst
  87. GRB 051109a: IR Detections
  88. GRB 051109: ROTSE-III Detection of Possible Counterpart
  89. GRB051105B: Swift/XRT upper limit
  90. GRB051105B: Swift/UVOT upper limit
  91. GRB051103: optical observations
  92. GRB 051103, optical observations
  93. GRB051103: MASTER: OT limit and host galaxy candidates
  94. GRB051028: Swift-XRT refined analysis
  95. GRB 051105a, observation from Naini Tal and OSN
  96. GRB 051105A, 2nd epoch optical observations
  97. GRB 051105a: MDM Observations
  98. GRB 051105A: TNG optical observations
  99. GRB051105A: Swift/UVOT Observations
  100. GRB 051105A, radio observations

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