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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"

23445 results found.

  1. GRB061007: Swift UVOT followup observations
  2. GRB 061006: optical afterglow
  3. GRB 061007: OA fading and VLT redshift
  4. GRB 061007: Swift XRT refined analysis
  5. GRB 061006: Swift/UVOT optical observations
  6. Konus-Wind observation of the short hard GRB 061006
  7. GRB 061007: Swift detection of a burst with an optical counterpart
  8. GRB 061006: VLT observation
  9. GRB 061006: Swift-XRT Team Refined Analysis
  10. GRB061006 (Swift 232585) might be a short-hard GRB
  11. GRB 060930: near-IR afterglow candidate retraction
  12. GRB 061006: Swift detection of a burst
  13. GRB 061004: Optical afterglow candidate and redshift
  14. GRB 061004: Las Campanas Optical/NIR Observations
  15. GRB061004: Swift/UVOT optical observations
  16. GRB 061004: Swift detection of a burst
  17. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  18. GRB 060928: Swift observations
  19. IPN triangulation of GRB060928 (long, exceptionally bright)
  20. GRB061002: Swift UVOT followup observations
  21. GRB 060930: near-IR afterglow candidate
  22. GRB 061002: Swift-XRT Team Refined Analysis
  23. VLA observations of GRB 060926
  24. GRB061002 - SDSS Pre-Burst Observations
  25. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  26. GRB 061002: Swift detection of a burst
  27. GRB 060908: Detection of a possible host
  28. GRB 060807: Detection of a possible host galaxy
  29. GRB 060923A: VLA K-band Observations
  30. GRB 060930: Xinglong TNT optical observations
  31. GRB 060929: Swift/UVOT Optical Observations
  32. GRB 060930: ROTSE-III Optical Limits
  33. GRB 060929: TNG K-band observations
  34. GRB 060929, Swift-BAT refined analysis
  35. GRB060929: Optical limit
  36. Liverpool Telescope observations of GRB 060929
  37. GRB060908: optical observations
  38. GRB 060729: An update on the late-time Swift observations
  39. GRB060923C: optical limit
  40. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  41. GRB 060927: Swift/UVOT Optical Observations
  42. GRB 060927: Swift XRT Team refined analysis
  43. GRB 060927 optical limit
  44. GRB 060927: Xinglong TNT optical observations
  45. GRB 060927, optical observation
  46. GRB060927 - SDSS Pre-Burst Observations
  47. GRB 060927: Swift detection of a burst
  48. GRB 060926: Swift-UVOT Detections
  49. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  50. GRB 060926: Swift XRT refined analysis
  51. GRB 060923A: Radio Observations
  52. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  53. GRB 060926: BOOTES-IR observations
  54. GRB 060926: Swift detection of a burst
  55. GRB 060923C: VLA Observation
  56. GRB 060923C: NIR afterglow confirmed
  57. GRB060923C: AROMA optical obsevation
  58. GRB 060923C, optical observation
  59. GRB 060923C: VLT J-band observations
  60. GRB060923B: Swift/UVOT upper limits
  61. GRB 060923A: Keck and Gemini Observations
  62. GRB 060923C: Xinglong TNT optical observations
  63. GRB 060923C: optical observation
  64. GRB 060923C: Swift detection of a burst
  65. GRB 060923B: Swift detection of a burst
  66. GRB 060923: Early Super-LOTIS Observations
  67. GRB 060923: UKIRT nIR observations - candidate afterglow
  68. GRB060923 - SDSS Pre-Burst Observations
  69. GRB 060923: Swift detection of a burst
  70. Swift detection of IGR J17497-2821 (trigger 230504)
  71. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216
  72. GRB060919: Swift/UVOT optical observations
  73. GRB 060919 : Faulkes South Telescope Observations
  74. GRB 060919: TAROT optical observations
  75. GRB 060919: Swift detection of a burst
  76. GRB 060912A: VLA Observation
  77. GRB 060912A: Probable Host Galaxy
  78. GRB 060912: Correction to GCN 5559
  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, Swift-BAT refined analysis
  83. GRB 060908 - SDSS Pre-burst Observations
  84. GRB 060904A : Optical limit
  85. GRB 060908: REM optical prompt observation
  86. GRB 060908: Swift detection of a burst with a bright optical counterpart
  87. GRB060906 , optical observation
  88. GRB 060906: Early RAPTOR optical limits
  89. GRB 060906, Swift-BAT refined spectral analysis
  90. GRB 060906: Swift-UVOT observations
  91. GRB 060906: KAIT observations
  92. GRB 060906: Confirmation of P60 Optical Afterglow
  93. GRB 060906 (?): P60 Optical Afterglow Candidate
  94. GRB 060906: Swift detection of a probable burst
  95. GRB060904b, optical observations
  96. GRB060904A: Swift/UVOT optical observations
  97. GRB 060904A: Subaru NIR observation
  98. GRB060904b: Optical observations with Swift/UVOT
  99. GRB 060904B: Swift-XRT refined analysis
  100. GRB 060904A: Refined analysis of the Swift-BAT burst

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