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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"

27393 results found.

  1. GRB 061028: Swift/UVOT Observations
  2. GRB 061028, Swift-BAT refined analysis
  3. GRB 061028: TAROT Calern observatory optical observations
  4. GRB 061028: Swift detection of a burst
  5. GRB 061027, Swift refined analysis of a possible burst
  6. GRB 061027: Swift detection of a possible burst
  7. GRB061025: Swift XRT refined analysis
  8. GRB061025: Swift/UVOT observations
  9. GRB 061025: REM observations
  10. GRB 061025: ROTSE-III Optical Limits
  11. GRB 061025: a long GRB detected by INTEGRAL
  12. Swift XRT boresight update
  13. GRB 061021: Swift/UVOT Observation
  14. GRB 061021, Swift-BAT refined analysis
  15. GRB 061021: Swift detection of a burst
  16. GRB061019: optical observations
  17. GRB 061019: SARA upper limit
  18. GRB 061019: Swift/UVOT upper limit
  19. GRB 061019: SMARTS afterglow confirmation
  20. GRB061019: Swift XRT refined analysis
  21. GRB 061019, Swift-BAT refined analysis
  22. GRB 061019: TAROT La Silla observatory optical observations
  23. GRB 061019: REM K-band candidate afterglow
  24. GRB 061007: Second Epoch ATCA Radio Observations
  25. GRB 061007: Suzaku/WAM observation of the prompt emission
  26. GRB 061006: astrometry-corrected XRT position
  27. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  28. GRB 061007: ATCA Radio Observations
  29. GRB061007: Swift UVOT followup observations
  30. GRB 061006: optical afterglow
  31. GRB 061007: OA fading and VLT redshift
  32. GRB 061007: Correction to GCN 5712
  33. GRB 061007: Swift-BAT refined analysis
  34. GRB 061007: Swift XRT refined analysis
  35. GRB 061006: Swift/UVOT optical observations
  36. GRB 061007: Swift detection of a burst with an optical counterpart
  37. GRB 061007: ROTSE-III Detection of Optical Counterpart
  38. GRB 061006: VLT observation
  39. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  40. GRB 061006: Swift-XRT Team Refined Analysis
  41. GRB061006 (Swift 232585) might be a short-hard GRB
  42. GRB 060930: near-IR afterglow candidate retraction
  43. GRB 061004: Optical afterglow candidate and redshift
  44. GRB 061004: Swift-XRT Team Refined Analysis
  45. GRB 061004, Swift BAT refined analysis
  46. GRB 061004: Swift detection of a burst
  47. GRB 060928: Suzaku/WAM observation of the prompt emission
  48. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  49. GRB 060928: Swift observations
  50. IPN triangulation of GRB060928 (long, exceptionally bright)
  51. GRB 060930: near-IR afterglow candidate
  52. GRB 061002: Swift-XRT Team Refined Analysis
  53. VLA observations of GRB 060926
  54. GRB061002 - SDSS Pre-Burst Observations
  55. GRB 061002, Swift-BAT refined analysis
  56. GRB 060908: Detection of a possible host
  57. GRB 060807: Detection of a possible host galaxy
  58. GRB 060923A: VLA K-band Observations
  59. GRB 060930: Xinglong TNT optical observations
  60. GRB 060929: Further XRT Refined Analysis
  61. GRB 060929: Swift/UVOT Optical Observations
  62. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  63. GRB060929: Swift-XRT refined analysis.
  64. GRB 060929: TNG K-band observations
  65. GRB 060929, Swift-BAT refined analysis
  66. GRB060929: Optical limit
  67. Liverpool Telescope observations of GRB 060929
  68. GRB060908: optical observations
  69. GRB 060927: Swift/UVOT Optical Observations
  70. GRB 060927: Swift XRT Team refined analysis
  71. GRB 060927 optical limit
  72. GRB 060927, Swift-BAT refined analysis
  73. GRB 060927: Xinglong TNT optical observations
  74. GRB 060927, optical observation
  75. GRB060927 - SDSS Pre-Burst Observations
  76. Swift XRT boresight
  77. GRB060926: VLT redshift
  78. GRB 060926: Swift-UVOT Detections
  79. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  80. GRB 060926, Swift-BAT refined analysis
  81. GRB 060923A: Radio Observations
  82. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  83. GRB 060926: Swift detection of a burst
  84. GRB 060923C, Swift-BAT refined analysis
  85. GRB 060923C: VLA Observation
  86. GRB 060923C: NIR afterglow confirmed
  87. GRB060923C: AROMA optical obsevation
  88. GRB 060923C, optical observation
  89. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  90. GRB 060923C: VLT J-band observations
  91. GRB 060923B: Swift XRT Refined Analysis
  92. GRB 060923A: Swift XRT refined analysis
  93. GRB 060923A: Keck and Gemini Observations
  94. GRB 060923C: Xinglong TNT optical observations
  95. GRB 060923B, Swift-BAT refined analysis
  96. GRB 060923C: Swift detection of a burst
  97. GRB 060923B: Swift detection of a burst
  98. GRB 060923, Swift-BAT refined analysis
  99. GRB 060923: UKIRT nIR observations - candidate afterglow
  100. GRB060923 - SDSS Pre-Burst Observations

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