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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"

27391 results found.

  1. GRB 061028: TAROT Calern observatory optical observations
  2. GRB 061028: Swift detection of a burst
  3. GRB 061027, Swift refined analysis of a possible burst
  4. GRB 061027: Swift detection of a possible burst
  5. GRB061025: Swift XRT refined analysis
  6. GRB061025: Swift/UVOT observations
  7. GRB 061025: REM observations
  8. GRB 061025: ROTSE-III Optical Limits
  9. GRB 061025: a long GRB detected by INTEGRAL
  10. Swift XRT boresight update
  11. GRB 061021: Swift/UVOT Observation
  12. GRB 061021, Swift-BAT refined analysis
  13. GRB 061021: Swift detection of a burst
  14. GRB061019: optical observations
  15. GRB 061019: SARA upper limit
  16. GRB 061019: Swift/UVOT upper limit
  17. GRB 061019: SMARTS afterglow confirmation
  18. GRB061019: Swift XRT refined analysis
  19. GRB 061019, Swift-BAT refined analysis
  20. GRB 061019: TAROT La Silla observatory optical observations
  21. GRB 061019: REM K-band candidate afterglow
  22. GRB 061007: Second Epoch ATCA Radio Observations
  23. GRB 061007: Suzaku/WAM observation of the prompt emission
  24. GRB 061006: astrometry-corrected XRT position
  25. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  26. GRB 061007: ATCA Radio Observations
  27. GRB061007: Swift UVOT followup observations
  28. GRB 061006: optical afterglow
  29. GRB 061007: OA fading and VLT redshift
  30. GRB 061007: Correction to GCN 5712
  31. GRB 061007: Swift-BAT refined analysis
  32. GRB 061007: Swift XRT refined analysis
  33. GRB 061006: Swift/UVOT optical observations
  34. GRB 061007: Swift detection of a burst with an optical counterpart
  35. GRB 061007: ROTSE-III Detection of Optical Counterpart
  36. GRB 061006: VLT observation
  37. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  38. GRB 061006: Swift-XRT Team Refined Analysis
  39. GRB061006 (Swift 232585) might be a short-hard GRB
  40. GRB 060930: near-IR afterglow candidate retraction
  41. GRB 061004: Optical afterglow candidate and redshift
  42. GRB 061004: Swift-XRT Team Refined Analysis
  43. GRB 061004, Swift BAT refined analysis
  44. GRB 061004: Swift detection of a burst
  45. GRB 060928: Suzaku/WAM observation of the prompt emission
  46. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  47. GRB 060928: Swift observations
  48. IPN triangulation of GRB060928 (long, exceptionally bright)
  49. GRB 060930: near-IR afterglow candidate
  50. GRB 061002: Swift-XRT Team Refined Analysis
  51. VLA observations of GRB 060926
  52. GRB061002 - SDSS Pre-Burst Observations
  53. GRB 061002, Swift-BAT refined analysis
  54. GRB 060908: Detection of a possible host
  55. GRB 060807: Detection of a possible host galaxy
  56. GRB 060923A: VLA K-band Observations
  57. GRB 060930: Xinglong TNT optical observations
  58. GRB 060929: Further XRT Refined Analysis
  59. GRB 060929: Swift/UVOT Optical Observations
  60. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  61. GRB060929: Swift-XRT refined analysis.
  62. GRB 060929: TNG K-band observations
  63. GRB 060929, Swift-BAT refined analysis
  64. GRB060929: Optical limit
  65. Liverpool Telescope observations of GRB 060929
  66. GRB060908: optical observations
  67. GRB 060927: Swift/UVOT Optical Observations
  68. GRB 060927: Swift XRT Team refined analysis
  69. GRB 060927 optical limit
  70. GRB 060927, Swift-BAT refined analysis
  71. GRB 060927: Xinglong TNT optical observations
  72. GRB 060927, optical observation
  73. GRB060927 - SDSS Pre-Burst Observations
  74. Swift XRT boresight
  75. GRB060926: VLT redshift
  76. GRB 060926: Swift-UVOT Detections
  77. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  78. GRB 060926, Swift-BAT refined analysis
  79. GRB 060923A: Radio Observations
  80. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  81. GRB 060926: Swift detection of a burst
  82. GRB 060923C, Swift-BAT refined analysis
  83. GRB 060923C: VLA Observation
  84. GRB 060923C: NIR afterglow confirmed
  85. GRB060923C: AROMA optical obsevation
  86. GRB 060923C, optical observation
  87. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  88. GRB 060923C: VLT J-band observations
  89. GRB 060923B: Swift XRT Refined Analysis
  90. GRB 060923A: Swift XRT refined analysis
  91. GRB 060923A: Keck and Gemini Observations
  92. GRB 060923C: Xinglong TNT optical observations
  93. GRB 060923B, Swift-BAT refined analysis
  94. GRB 060923C: Swift detection of a burst
  95. GRB 060923B: Swift detection of a burst
  96. GRB 060923, Swift-BAT refined analysis
  97. GRB 060923: UKIRT nIR observations - candidate afterglow
  98. GRB060923 - SDSS Pre-Burst Observations
  99. GRB 060923: Swift detection of a burst
  100. Swift detects a hard X-ray burst from AXP CXOU J164710.2-455216

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