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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"

26050 results found.

  1. GRB 051109A : Lulin BVRI Optical afterglow observation
  2. GRB051109A: further steepening in the X-ray light curve
  3. GRB051109A: XRT refined analysis
  4. GRB 051109a: BOOTES R & I-band detection of the early afterglow
  5. GRB051109B: XRT position
  6. GRB 051109B: Super-LOTIS Observations
  7. GRB 051109B Kiso optical follow-up observation
  8. GRB 051109B: Swift detection of a burst
  9. GRB 051109: HET Optical Spectrum and Absorption Redshift
  10. GRB 051109: PROMPT Detections
  11. GRB 051109: Rc and Ic observations
  12. GRB051109: Early Super-LOTIS Detection
  13. GRB 051109: Swift-BAT refined analysis
  14. GRB 051109a: MDM Observations
  15. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  16. GRB051109: Swift detection of a burst
  17. GRB 051109a: IR Detections
  18. GRB 051109: ROTSE-III Detection of Possible Counterpart
  19. GRB051105B: Swift/XRT upper limit
  20. GRB051105B: Swift/UVOT upper limit
  21. GRB051028: Swift-XRT refined analysis
  22. GRB 051105A, 2nd epoch optical observations
  23. GRB 051105a: MDM Observations
  24. GRB 051105A: TNG optical observations
  25. GRB051105A: Swift/UVOT Observations
  26. GRB 051105A, radio observations
  27. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  28. GRB 051105A, optical observations
  29. XRT observations of GRB 051105A
  30. GRB 051105: Swift-BAT improved refined analysis
  31. GRB 051105b: ART optical limits
  32. GRB 051105: Swift-BAT refined analysis
  33. GRB 051105: Optical limit
  34. GRB 051105: Swift detection of a short burst
  35. GRB 051016B host spectroscopy and redshift
  36. GRB051016B: optical observation
  37. GRB 051022: RTT150 optical observations
  38. GRB051028: optical observations
  39. GRB051028: Swift/UVOT upper limits
  40. GRB051028: confirmation of the afterglow
  41. GRB051028: WHT optical candidate
  42. GRB051028: Swift XRT Position
  43. GRB 051022: XRT Refined Spectral and Temporal Analysis--Correction
  44. GRB051022: Swift XRT measurement of jet break
  45. GRB051021B: Swift/UVOT Upper limits
  46. GRB 051022: XRT Refined Spectral and Temporal Analysis
  47. GRB051012: Swift-XRT analysis
  48. GRB051021B: Swift XRT refined analysis
  49. GRB051021a: optical observations
  50. GRB 051022: WSRT Radio Detection
  51. GRB051022: host galaxy redshift
  52. GRB 051022: Swift/UVOT Upper Limits
  53. GRB051022: Radio Counterpart
  54. GRB051022: IR observations
  55. GRB 051022: SOAR JKs Observations
  56. GRB051021A: Swift XRT refined analysis
  57. GRB051022: Optical Observations
  58. GRB 051022: Magellan NIR imaging
  59. GRB 051021: PROMPT RcIc Observations
  60. GRB051021b: Magellan IR Imaging
  61. GRB 051021: Correction
  62. GRB 051022, J & K-band observation
  63. GRB 051021, SMARTS optical/IR observations
  64. GRB051022: Swift XRT Position
  65. GRB 051021: P200 Ks Observations
  66. GRB 051021: MDM Upper Limit
  67. GRB051021: Swift/UVOT Upper Limits
  68. GRB 051021B: Refined analysis of the Swift-BAT burst
  69. GRB051021B: Swift XRT Position
  70. GRB 051021: SOAR NIR Observations
  71. GRB 051021B: Swift detection of a burst
  72. GRB051021: Swift XRT analysis
  73. GRB 051021 : optical afterglow observation at Lulin
  74. GRB 051021: Optical observations and candidate afterglow
  75. GRB051021.63
  76. Swift-BAT trigger 160640 is not a real GRB
  77. Swift-BAT trigger 160619 is not a GRB
  78. Swift-BAT triggered on a posible CR Shower or possible GRB
  79. GRB 050502b: Optical limit
  80. GRB 051016b: Optical limit
  81. Afterglow candidate of GRB 051016B observed at Lulin
  82. GRB 051016b: Gemini Near IR Observations
  83. GRB 051016A: Swift/UVOT upper limits
  84. GRB 051016B: refined analysis of the Swift/XRT data
  85. GRB 051016B: Swift/UVOT detection
  86. GRB 051016B : Optical follow-up at Lulin
  87. GRB 051016B: Refined analysis of the Swift-BAT burst
  88. GRB 051016B: Swift detection of a soft burst
  89. GRB 051016: Swift-BAT refined analysis
  90. GRB051016 XMM-Newton observation
  91. GRB051016: Swift XRT refined analysis.
  92. GRB 051016: LCO optical and near-IR imaging
  93. GRB 051016: PROMPT Observations
  94. GRB051016: Swift detection of a burst
  95. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  96. GRB051006: optical observations
  97. GRB 051012: Swift-BAT detection of burst yesterday
  98. Swift trigger 159578 is not a burst
  99. Swift-BAT Trigger 159578 is a possible burst
  100. GRB050805A: Rc optical observations

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