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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"

45642 results found.

  1. GRB 051103 Milagro GeV/TeV Observations
  2. GRB051111: Swift-BAT detection of a bright burst
  3. GRB 051111A: ROTSE-III Detection of Possible Counterpart
  4. GRB 051008 Tautenburg Supernova Search
  5. GRB 051109B. Radio Observations
  6. GRB 051109A
  7. GRB051109A - radio observations
  8. GRB 051105a: GETS optical limit
  9. GRB 051109b: GETS observation
  10. GRB 051109A: KAIT optical observations
  11. Early RAPTOR measurements of GRB 051109a - the movie.
  12. Konus-Wind observation of GRB 051109A
  13. GRB 051109B: Swift-BAT refined analysis
  14. GRB 051109B: ROTSE-III Optical Limits
  15. GRB 051109A: Swift-UVOT Observations
  16. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  17. GRB051109B: no UVOT source detected
  18. GRB051109B: XRT refined analysis
  19. GRB 051109B : Lulin Optical Observations
  20. GRB 051109A : Lulin BVRI Optical afterglow observation
  21. GRB051109A: further steepening in the X-ray light curve
  22. GRB051109A: XRT refined analysis
  23. GRB 051109a: BOOTES R & I-band detection of the early afterglow
  24. GRB051109B: XRT position
  25. GRB 051109B: Super-LOTIS Observations
  26. GRB 051109B Kiso optical follow-up observation
  27. GRB051105B: REM Optical observation
  28. GRB 051109B: Swift detection of a burst
  29. GRB 051109: HET Optical Spectrum and Absorption Redshift
  30. GRB 051109: PROMPT Detections
  31. GRB 051109: Rc and Ic observations
  32. GRB051109: Early Super-LOTIS Detection
  33. GRB 051109: Swift-BAT refined analysis
  34. GRB 051109a: IR Photometry and Astrometry
  35. GRB 051109a: MDM Observations
  36. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  37. GRB051109: Swift detection of a burst
  38. GRB 051109a: IR Detections
  39. GRB 051109: ROTSE-III Detection of Possible Counterpart
  40. GRB051105B: Swift/XRT upper limit
  41. GRB051105B: Swift/UVOT upper limit
  42. GRB051103: optical observations
  43. GRB 051103, optical observations
  44. GRB051103: MASTER: OT limit and host galaxy candidates
  45. GRB051028: Swift-XRT refined analysis
  46. GRB 051105a, observation from Naini Tal and OSN
  47. GRB 051105A, 2nd epoch optical observations
  48. GRB 051105a: MDM Observations
  49. GRB 051105A: TNG optical observations
  50. GRB051105A: Swift/UVOT Observations
  51. GRB 051105A, radio observations
  52. GRB051103:_MASTER_optical_observations
  53. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  54. GRB 051105A, optical observations
  55. XRT observations of GRB 051105A
  56. GRB 051105: Swift-BAT improved refined analysis
  57. GRB 051105b: ART optical limits
  58. GRB051105B - A long GRB detected by INTEGRAL
  59. GRB 051105B (INTEGRAL 2701): Optical observation
  60. GRB 051105: Swift-BAT refined analysis
  61. GRB 051105: Optical limit
  62. GRB 051105: Swift detection of a short burst
  63. IBAS Alert 2700: Not a GRB
  64. GRB 051016B host spectroscopy and redshift
  65. GRB051016B: optical observation
  66. Recent GRB UBVRcIc field photometry
  67. Konus-Wind observation of GRB 051028
  68. GRB051028:MASTER correction and final results
  69. GRB 051022: RTT150 optical observations
  70. GRB 051021A: RTT150 optical observations
  71. GRB051028 SARA Observation
  72. GRB051028: optical observations
  73. GRB051028: Swift/UVOT upper limits
  74. GRB051028: confirmation of the afterglow
  75. GRB051028: WHT optical candidate
  76. GRB051028: Swift XRT Position
  77. GRB051028:MASTER observations
  78. GRB 051028 (=H3951): A GRB localized by HETE
  79. GRB051028:MASTER optical observations
  80. GRB 051022: XRT Refined Spectral and Temporal Analysis--Correction
  81. GRB051022: Swift XRT measurement of jet break
  82. SGR 1806-20: continued moderate activity seen with INTEGRAL
  83. GRB051021B: Swift/UVOT Upper limits
  84. GRB 051021, Optical Observations
  85. GRB 051022: XRT Refined Spectral and Temporal Analysis
  86. GRB 051022, refined optical astrometry
  87. Chandra Observations of GRB 051022
  88. GRB051012: Swift-XRT analysis
  89. GRB 051022 Chandra Observations scheduled
  90. GRB051021B: Swift XRT refined analysis
  91. GRB051021a: optical observations
  92. GRB 051022: WSRT Radio Detection
  93. GRB 051022, mm counterpart
  94. GRB051022: host galaxy redshift
  95. GRB 051022: Swift/UVOT Upper Limits
  96. GRB051022: Radio Counterpart
  97. GRB051022: IR observations
  98. GRB 051022: SOAR JKs Observations
  99. GRB051021A: Swift XRT refined analysis
  100. Konus-Wind observation of GRB 051022

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