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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. GRB 060927, optical observation
  2. GRB 060927: Possible host galaxy (star?) in the SDSS
  3. GRB 060927 : Kiso optical observation
  4. GRB060927: Faulkes Telescope South observation
  5. GRB 060926: MASTER: first minutes decay
  6. GRB060927 - SDSS Pre-Burst Observations
  7. GRB 060927: optical afterglow confirmation
  8. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  9. Swift XRT boresight
  10. GRB 060927: Swift detection of a burst
  11. GRB060926: VLT redshift
  12. GRB 060926: Swift-UVOT Detections
  13. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  14. GRB 060926: OPTIMA-Burst -- further observations
  15. GRB 060926: Swift XRT refined analysis
  16. GRB 060926, Swift-BAT refined analysis
  17. GRB 060923A: Radio Observations
  18. GRB 060926: MASTER OT alert observation
  19. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  20. GRB 060912A: Redshift of probable host galaxy
  21. GRB 060926: BOOTES-IR observations
  22. GRB 060926: Watcher observations
  23. GRB060926 OPTIMA-Burst optical observation
  24. GRB 060926: MASTER optical observation
  25. GRB 060926: Swift detection of a burst
  26. GRB 060923C, Swift-BAT refined analysis
  27. GRB 060923C: VLA Observation
  28. GRB 060923C: NIR afterglow confirmed
  29. GRB060923C: AROMA optical obsevation
  30. GRB 060923C: Gemini Observations and Afterglow Candidate
  31. GRB 060923C, optical observation
  32. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  33. GRB 060923C: VLT J-band observations
  34. GRB060923B: Swift/UVOT upper limits
  35. GRB 060923B: Swift XRT Refined Analysis
  36. GRB 060923C: Swift XRT refined analysis
  37. GRB 060923C, Swift-BAT partial refined analysis
  38. GRB 060923A: Swift XRT refined analysis
  39. GRB 060923C: Keck Observations
  40. GRB 060923A: Keck and Gemini Observations
  41. GRB 060923C: Xinglong TNT optical observations
  42. GRB 060923B, Swift-BAT refined analysis
  43. GRB060923C : Faulkes Telescope South optical limits
  44. GRB060923C: Faulkes Telescope North optical observations
  45. GRB 060923C: optical observation
  46. GRB 060923C: Swift detection of a burst
  47. GRB 060923B: Swift detection of a burst
  48. GRB 060923, Swift-BAT refined analysis
  49. GRB 060923: Early Super-LOTIS Observations
  50. GRB 060923: UKIRT nIR observations - candidate afterglow
  51. GRB060923: Faulkes Telescope North optical observations
  52. GRB060923 - SDSS Pre-Burst Observations
  53. GRB 060923: KAIT observations
  54. GRB 060923: Swift detection of a burst
  55. Swift detection of IGR J17497-2821 (trigger 230504)
  56. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  57. GRB060919: Swift/UVOT optical observations
  58. GRB 060919 : Faulkes South Telescope Observations
  59. GRB 060919, Swift-BAT refined analysis
  60. GRB060919: XRT refined analysis
  61. GRB 060919: TAROT optical observations
  62. GRB 060919: Swift detection of a burst
  63. GRB 060912A: VLA Observation
  64. GRB 060912A: Probable Host Galaxy
  65. IBAS Alert n.3470: not a GRB
  66. GRB060825: MAGIC telescope GeV observation
  67. Konus-Wind observation of GRB 060912
  68. IBAS Alert No.3468: not a GRB
  69. GRB 060912: Redshift of nearby 2MASS galaxy
  70. GRB060912: optical observations
  71. GRB 060912B: Watcher observations
  72. GRB060912: Swift/UVOT Observations
  73. GRB060912: OPTIMA-Burst optical observations
  74. GRB 060912B: a long GRB detected with INTEGRAL
  75. GRB 060912: Swift XRT Team Refined Analysis
  76. GRB 060912, Swift-BAT refined analysis
  77. GRB 060912: Correction to GCN 5559
  78. GRB 060912: Xinglong TNT optical observations
  79. GRB 060912: Swift detection of a burst with an optical afterglow
  80. GRB060906: Danish/DFOSC optical observations
  81. VLA observations of GRB 060908
  82. GRB 060908: redshift
  83. GRB 060908, Swift/XRT refined analysis
  84. GRB 060908: Swift/UVOT Observations
  85. GRB 060908: Danish/DFOSC optical observations
  86. GRB 060908, Swift-BAT refined analysis
  87. GRB 060908 - SDSS Pre-burst Observations
  88. GRB 060904B : CFHT/WIRCam NIR afterglow observations
  89. GRB 060904B: Kiso Optical observation
  90. GRB 060904A : Optical limit
  91. GRB 060908: REM optical prompt observation
  92. GRB 060908: PROMPT Detection of a Bright Counterpart
  93. GRB 060908: Swift detection of a burst with a bright optical counterpart
  94. GRB 060904A: Suzaku/WAM observation of the prompt emission
  95. GRB060906 , optical observation
  96. GRB060904b optical detections (delayed report due to internet outage)
  97. GRB 060906: optical observation
  98. GRB 060906: Early RAPTOR optical limits
  99. GRB 060906, Swift-BAT refined spectral analysis
  100. GRB 060906: Swift/XRT Refined Analysis

Advanced

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