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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"

27400 results found.

  1. GRB 061004: Swift/XRT Astrometry Correction
  2. GRB 060801: Swift/XRT Astrometry Correction
  3. GRB 061028: Futher P200 Observations
  4. GRB 061028: P200 Observations
  5. GRB 061028: SARA upper limit
  6. GRB 061028: z band imaging
  7. GRB061028: XRT refined analysis
  8. GRB 061028: Swift/UVOT Observations
  9. GRB 061028, Swift-BAT refined analysis
  10. GRB 061028: TAROT Calern observatory optical observations
  11. GRB 061028: Swift detection of a burst
  12. GRB 061027, Swift refined analysis of a possible burst
  13. GRB 061027: Swift detection of a possible burst
  14. GRB061025: Swift XRT refined analysis
  15. GRB061025: Swift/UVOT observations
  16. GRB 061025: REM observations
  17. GRB 061025: ROTSE-III Optical Limits
  18. GRB 061025: a long GRB detected by INTEGRAL
  19. Swift XRT boresight update
  20. GRB 061021: Swift/UVOT Observation
  21. GRB 061021, Swift-BAT refined analysis
  22. GRB 061021: Swift detection of a burst
  23. GRB061019: optical observations
  24. GRB 061019: SARA upper limit
  25. GRB 061019: Swift/UVOT upper limit
  26. GRB 061019: SMARTS afterglow confirmation
  27. GRB061019: Swift XRT refined analysis
  28. GRB 061019, Swift-BAT refined analysis
  29. GRB 061019: TAROT La Silla observatory optical observations
  30. GRB 061019: REM K-band candidate afterglow
  31. GRB 061007: Second Epoch ATCA Radio Observations
  32. GRB 061007: Suzaku/WAM observation of the prompt emission
  33. GRB 061006: astrometry-corrected XRT position
  34. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  35. GRB 061007: ATCA Radio Observations
  36. GRB061007: Swift UVOT followup observations
  37. GRB 061006: optical afterglow
  38. GRB 061007: OA fading and VLT redshift
  39. GRB 061007: Correction to GCN 5712
  40. GRB 061007: Swift-BAT refined analysis
  41. GRB 061007: Swift XRT refined analysis
  42. GRB 061006: Swift/UVOT optical observations
  43. GRB 061007: Swift detection of a burst with an optical counterpart
  44. GRB 061007: ROTSE-III Detection of Optical Counterpart
  45. GRB 061006: VLT observation
  46. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  47. GRB 061006: Swift-XRT Team Refined Analysis
  48. GRB061006 (Swift 232585) might be a short-hard GRB
  49. GRB 060930: near-IR afterglow candidate retraction
  50. GRB 061004: Optical afterglow candidate and redshift
  51. GRB 061004: Swift-XRT Team Refined Analysis
  52. GRB 061004, Swift BAT refined analysis
  53. GRB 061004: Swift detection of a burst
  54. GRB 060928: Suzaku/WAM observation of the prompt emission
  55. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  56. GRB 060928: Swift observations
  57. IPN triangulation of GRB060928 (long, exceptionally bright)
  58. GRB 060930: near-IR afterglow candidate
  59. GRB 061002: Swift-XRT Team Refined Analysis
  60. VLA observations of GRB 060926
  61. GRB061002 - SDSS Pre-Burst Observations
  62. GRB 061002, Swift-BAT refined analysis
  63. GRB 060908: Detection of a possible host
  64. GRB 060807: Detection of a possible host galaxy
  65. GRB 060923A: VLA K-band Observations
  66. GRB 060930: Xinglong TNT optical observations
  67. GRB 060929: Further XRT Refined Analysis
  68. GRB 060929: Swift/UVOT Optical Observations
  69. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  70. GRB060929: Swift-XRT refined analysis.
  71. GRB 060929: TNG K-band observations
  72. GRB 060929, Swift-BAT refined analysis
  73. GRB060929: Optical limit
  74. Liverpool Telescope observations of GRB 060929
  75. GRB060908: optical observations
  76. GRB 060927: Swift/UVOT Optical Observations
  77. GRB 060927: Swift XRT Team refined analysis
  78. GRB 060927 optical limit
  79. GRB 060927, Swift-BAT refined analysis
  80. GRB 060927: Xinglong TNT optical observations
  81. GRB 060927, optical observation
  82. GRB060927 - SDSS Pre-Burst Observations
  83. Swift XRT boresight
  84. GRB060926: VLT redshift
  85. GRB 060926: Swift-UVOT Detections
  86. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  87. GRB 060926, Swift-BAT refined analysis
  88. GRB 060923A: Radio Observations
  89. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  90. GRB 060926: Swift detection of a burst
  91. GRB 060923C, Swift-BAT refined analysis
  92. GRB 060923C: VLA Observation
  93. GRB 060923C: NIR afterglow confirmed
  94. GRB060923C: AROMA optical obsevation
  95. GRB 060923C, optical observation
  96. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  97. GRB 060923C: VLT J-band observations
  98. GRB 060923B: Swift XRT Refined Analysis
  99. GRB 060923A: Swift XRT refined analysis
  100. GRB 060923A: Keck and Gemini Observations

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