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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"

42185 results found.

  1. GRB 051111: Keck HIRES redshift
  2. GRB 051111A: KAIT optical observations
  3. GRB 051111: ROTSE-III Analysis of Prompt Counterpart
  4. GRB 051103 Milagro GeV/TeV Observations
  5. GRB051111: Swift-BAT detection of a bright burst
  6. GRB 051111A: ROTSE-III Detection of Possible Counterpart
  7. GRB 051008 Tautenburg Supernova Search
  8. GRB 051109B. Radio Observations
  9. GRB 051109A
  10. GRB051109A - radio observations
  11. GRB 051105a: GETS optical limit
  12. GRB 051109A: KAIT optical observations
  13. Early RAPTOR measurements of GRB 051109a - the movie.
  14. Konus-Wind observation of GRB 051109A
  15. GRB 051109B: ROTSE-III Optical Limits
  16. GRB 051109A: Swift-UVOT Observations
  17. IPN triangulation and Konus spectrum of the short/soft GRB051107 (large
  18. GRB051109B: no UVOT source detected
  19. GRB051109B: XRT refined analysis
  20. GRB 051109B : Lulin Optical Observations
  21. GRB 051109A : Lulin BVRI Optical afterglow observation
  22. GRB051109A: further steepening in the X-ray light curve
  23. GRB051109A: XRT refined analysis
  24. GRB 051109a: BOOTES R & I-band detection of the early afterglow
  25. GRB051109B: XRT position
  26. GRB 051109B: Super-LOTIS Observations
  27. GRB 051109B Kiso optical follow-up observation
  28. GRB051105B: REM Optical observation
  29. GRB 051109B: Swift detection of a burst
  30. GRB 051109: HET Optical Spectrum and Absorption Redshift
  31. GRB 051109: PROMPT Detections
  32. GRB 051109: Rc and Ic observations
  33. GRB 051109: Swift-BAT refined analysis
  34. GRB 051109a: IR Photometry and Astrometry
  35. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  36. GRB051109: Swift detection of a burst
  37. GRB 051109: ROTSE-III Detection of Possible Counterpart
  38. GRB051105B: Swift/XRT upper limit
  39. GRB051105B: Swift/UVOT upper limit
  40. GRB051103: optical observations
  41. GRB 051103, optical observations
  42. GRB051103: MASTER: OT limit and host galaxy candidates
  43. GRB051028: Swift-XRT refined analysis
  44. GRB 051105a, observation from Naini Tal and OSN
  45. GRB 051105A, 2nd epoch optical observations
  46. GRB 051105a: MDM Observations
  47. GRB 051105A: TNG optical observations
  48. GRB051105A: Swift/UVOT Observations
  49. GRB 051105A, radio observations
  50. IPN triangulation and Konus spectrum of the bright short/hard GRB051103
  51. GRB 051105A, optical observations
  52. XRT observations of GRB 051105A
  53. GRB 051105b: ART optical limits
  54. GRB051105B - A long GRB detected by INTEGRAL
  55. GRB 051105B (INTEGRAL 2701): Optical observation
  56. GRB 051105: Swift-BAT refined analysis
  57. GRB 051105: Optical limit
  58. GRB 051105: Swift detection of a short burst
  59. GRB 051016B host spectroscopy and redshift
  60. GRB051016B: optical observation
  61. Recent GRB UBVRcIc field photometry
  62. Konus-Wind observation of GRB 051028
  63. GRB 051022: RTT150 optical observations
  64. GRB 051021A: RTT150 optical observations
  65. GRB051028 SARA Observation
  66. GRB051028: optical observations
  67. GRB051028: Swift/UVOT upper limits
  68. GRB051028: confirmation of the afterglow
  69. GRB051028: WHT optical candidate
  70. GRB051028: Swift XRT Position
  71. GRB051028:MASTER observations
  72. GRB 051028 (=H3951): A GRB localized by HETE
  73. GRB051028:MASTER optical observations
  74. GRB 051022: XRT Refined Spectral and Temporal Analysis--Correction
  75. SGR 1806-20: continued moderate activity seen with INTEGRAL
  76. GRB 051021, Optical Observations
  77. GRB 051022: XRT Refined Spectral and Temporal Analysis
  78. GRB 051022, refined optical astrometry
  79. Chandra Observations of GRB 051022
  80. GRB051012: Swift-XRT analysis
  81. GRB 051022 Chandra Observations scheduled
  82. GRB051021B: Swift XRT refined analysis
  83. GRB051021a: optical observations
  84. GRB 051022: WSRT Radio Detection
  85. GRB 051022, mm counterpart
  86. GRB051022: host galaxy redshift
  87. GRB 051022: Swift/UVOT Upper Limits
  88. GRB051022: Radio Counterpart
  89. GRB051022: IR observations
  90. GRB 051022: SOAR JKs Observations
  91. GRB051021A: Swift XRT refined analysis
  92. Konus-Wind observation of GRB 051022
  93. GRB051022: Optical Observations
  94. GRB 051022: Magellan NIR imaging
  95. GRB051021b: Magellan IR Imaging
  96. GRB 051022: Spectral Analysis Indicates That The Spectrum Is Absorbed
  97. GRB 051022, J & K-band observation
  98. GRB 051021, SMARTS optical/IR observations
  99. GRB051022: Swift XRT Position
  100. GRB 051021: P200 Ks Observations

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