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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"

26923 results found.

  1. GRB 061110B, Swift-BAT refined analysis
  2. GRB061110B: Optical observations at Crni Vrh
  3. GRB 061110A: Swift XRT refined analysis
  4. GRB 061110A, Swift-BAT refined analysis
  5. GRB 061110B: TAROT Calern observatory optical observations
  6. GRB 061110B: Swift detection of a burst
  7. GRB 061110: Candidate confirmed
  8. GRB 061110 : Optical afterglow candidate
  9. GRB 061110: ROTSE-III Optical Limits
  10. GRB 061110: Swift detection of a burst
  11. GRB061110A - Optical Non-detection
  12. GRB 061109: optical observation
  13. GRB 061109: TAROT Calern observatory optical observations
  14. GRB 061027: TAROT La Silla observatory optical observations
  15. GRB 061028: Swift/XRT Astrometry Correction
  16. GRB 061102: Swift/UVOT Magnitude Upper Limits
  17. GRB 061102, XRT refined analysis
  18. GRB061102B: Super-LOTIS observations
  19. GRB 061028: Optical R passband observations
  20. GRB 061102B: Swift detection of a possible burst
  21. GRB 061102, Swift-BAT refined analysis
  22. GRB 061102: Swift detection of a burst
  23. GRB 061028: VLA Observation
  24. GRB 061004: Swift/XRT Astrometry Correction
  25. GRB 060801: Swift/XRT Astrometry Correction
  26. GRB 061028: Futher P200 Observations
  27. GRB 061028: P200 Observations
  28. GRB 061028: SARA upper limit
  29. GRB 061028: z band imaging
  30. GRB061028: XRT refined analysis
  31. GRB 061028: Swift/UVOT Observations
  32. GRB 061028, Swift-BAT refined analysis
  33. GRB 061028: TAROT Calern observatory optical observations
  34. GRB 061028: Swift detection of a burst
  35. GRB 061027, Swift refined analysis of a possible burst
  36. GRB 061027: Swift detection of a possible burst
  37. GRB061025: Swift XRT refined analysis
  38. GRB061025: Swift/UVOT observations
  39. GRB 061025: REM observations
  40. GRB 061025: ROTSE-III Optical Limits
  41. GRB 061025: a long GRB detected by INTEGRAL
  42. Swift XRT boresight update
  43. GRB 061021: Swift/UVOT Observation
  44. GRB 061021, Swift-BAT refined analysis
  45. GRB 061021: Swift detection of a burst
  46. GRB061019: optical observations
  47. GRB 061019: SARA upper limit
  48. GRB 061019: Swift/UVOT upper limit
  49. GRB 061019: SMARTS afterglow confirmation
  50. GRB061019: Swift XRT refined analysis
  51. GRB 061019, Swift-BAT refined analysis
  52. GRB 061019: TAROT La Silla observatory optical observations
  53. GRB 061019: REM K-band candidate afterglow
  54. GRB 061007: Second Epoch ATCA Radio Observations
  55. GRB 061007: Suzaku/WAM observation of the prompt emission
  56. GRB 061006: astrometry-corrected XRT position
  57. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  58. GRB 061007: ATCA Radio Observations
  59. GRB061007: Swift UVOT followup observations
  60. GRB 061006: optical afterglow
  61. GRB 061007: OA fading and VLT redshift
  62. GRB 061007: Correction to GCN 5712
  63. GRB 061007: Swift-BAT refined analysis
  64. GRB 061007: Swift XRT refined analysis
  65. GRB 061006: Swift/UVOT optical observations
  66. GRB 061007: Swift detection of a burst with an optical counterpart
  67. GRB 061007: ROTSE-III Detection of Optical Counterpart
  68. GRB 061006: VLT observation
  69. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  70. GRB 061006: Swift-XRT Team Refined Analysis
  71. GRB061006 (Swift 232585) might be a short-hard GRB
  72. GRB 060930: near-IR afterglow candidate retraction
  73. GRB 061004: Optical afterglow candidate and redshift
  74. GRB 061004: Swift-XRT Team Refined Analysis
  75. GRB 061004, Swift BAT refined analysis
  76. GRB 061004: Swift detection of a burst
  77. GRB 060928: Suzaku/WAM observation of the prompt emission
  78. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  79. GRB 060928: Swift observations
  80. IPN triangulation of GRB060928 (long, exceptionally bright)
  81. GRB 060930: near-IR afterglow candidate
  82. GRB 061002: Swift-XRT Team Refined Analysis
  83. VLA observations of GRB 060926
  84. GRB061002 - SDSS Pre-Burst Observations
  85. GRB 061002, Swift-BAT refined analysis
  86. GRB 060908: Detection of a possible host
  87. GRB 060807: Detection of a possible host galaxy
  88. GRB 060923A: VLA K-band Observations
  89. GRB 060930: Xinglong TNT optical observations
  90. GRB 060929: Further XRT Refined Analysis
  91. GRB 060929: Swift/UVOT Optical Observations
  92. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  93. GRB060929: Swift-XRT refined analysis.
  94. GRB 060929: TNG K-band observations
  95. GRB 060929, Swift-BAT refined analysis
  96. GRB060929: Optical limit
  97. Liverpool Telescope observations of GRB 060929
  98. GRB060908: optical observations
  99. GRB 060927: Swift/UVOT Optical Observations
  100. GRB 060927: Swift XRT Team refined analysis

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