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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"

27402 results found.

  1. GRB 061102: Swift detection of a burst
  2. GRB 061028: VLA Observation
  3. GRB 061004: Swift/XRT Astrometry Correction
  4. GRB 060801: Swift/XRT Astrometry Correction
  5. GRB 061028: Futher P200 Observations
  6. GRB 061028: P200 Observations
  7. GRB 061028: SARA upper limit
  8. GRB 061028: z band imaging
  9. GRB061028: XRT refined analysis
  10. GRB 061028: Swift/UVOT Observations
  11. GRB 061028, Swift-BAT refined analysis
  12. GRB 061028: TAROT Calern observatory optical observations
  13. GRB 061028: Swift detection of a burst
  14. GRB 061027, Swift refined analysis of a possible burst
  15. GRB 061027: Swift detection of a possible burst
  16. GRB061025: Swift XRT refined analysis
  17. GRB061025: Swift/UVOT observations
  18. GRB 061025: REM observations
  19. GRB 061025: ROTSE-III Optical Limits
  20. GRB 061025: a long GRB detected by INTEGRAL
  21. Swift XRT boresight update
  22. GRB 061021: Swift/UVOT Observation
  23. GRB 061021, Swift-BAT refined analysis
  24. GRB 061021: Swift detection of a burst
  25. GRB061019: optical observations
  26. GRB 061019: SARA upper limit
  27. GRB 061019: Swift/UVOT upper limit
  28. GRB 061019: SMARTS afterglow confirmation
  29. GRB061019: Swift XRT refined analysis
  30. GRB 061019, Swift-BAT refined analysis
  31. GRB 061019: TAROT La Silla observatory optical observations
  32. GRB 061019: REM K-band candidate afterglow
  33. GRB 061007: Second Epoch ATCA Radio Observations
  34. GRB 061007: Suzaku/WAM observation of the prompt emission
  35. GRB 061006: astrometry-corrected XRT position
  36. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  37. GRB 061007: ATCA Radio Observations
  38. GRB061007: Swift UVOT followup observations
  39. GRB 061006: optical afterglow
  40. GRB 061007: OA fading and VLT redshift
  41. GRB 061007: Correction to GCN 5712
  42. GRB 061007: Swift-BAT refined analysis
  43. GRB 061007: Swift XRT refined analysis
  44. GRB 061006: Swift/UVOT optical observations
  45. GRB 061007: Swift detection of a burst with an optical counterpart
  46. GRB 061007: ROTSE-III Detection of Optical Counterpart
  47. GRB 061006: VLT observation
  48. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  49. GRB 061006: Swift-XRT Team Refined Analysis
  50. GRB061006 (Swift 232585) might be a short-hard GRB
  51. GRB 060930: near-IR afterglow candidate retraction
  52. GRB 061004: Optical afterglow candidate and redshift
  53. GRB 061004: Swift-XRT Team Refined Analysis
  54. GRB 061004, Swift BAT refined analysis
  55. GRB 061004: Swift detection of a burst
  56. GRB 060928: Suzaku/WAM observation of the prompt emission
  57. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  58. GRB 060928: Swift observations
  59. IPN triangulation of GRB060928 (long, exceptionally bright)
  60. GRB 060930: near-IR afterglow candidate
  61. GRB 061002: Swift-XRT Team Refined Analysis
  62. VLA observations of GRB 060926
  63. GRB061002 - SDSS Pre-Burst Observations
  64. GRB 061002, Swift-BAT refined analysis
  65. GRB 060908: Detection of a possible host
  66. GRB 060807: Detection of a possible host galaxy
  67. GRB 060923A: VLA K-band Observations
  68. GRB 060930: Xinglong TNT optical observations
  69. GRB 060929: Further XRT Refined Analysis
  70. GRB 060929: Swift/UVOT Optical Observations
  71. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  72. GRB060929: Swift-XRT refined analysis.
  73. GRB 060929: TNG K-band observations
  74. GRB 060929, Swift-BAT refined analysis
  75. GRB060929: Optical limit
  76. Liverpool Telescope observations of GRB 060929
  77. GRB060908: optical observations
  78. GRB 060927: Swift/UVOT Optical Observations
  79. GRB 060927: Swift XRT Team refined analysis
  80. GRB 060927 optical limit
  81. GRB 060927, Swift-BAT refined analysis
  82. GRB 060927: Xinglong TNT optical observations
  83. GRB 060927, optical observation
  84. GRB060927 - SDSS Pre-Burst Observations
  85. Swift XRT boresight
  86. GRB060926: VLT redshift
  87. GRB 060926: Swift-UVOT Detections
  88. GRB 060923A: Schedule of Spitzer Space Telescope Observations
  89. GRB 060926, Swift-BAT refined analysis
  90. GRB 060923A: Radio Observations
  91. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  92. GRB 060926: Swift detection of a burst
  93. GRB 060923C, Swift-BAT refined analysis
  94. GRB 060923C: VLA Observation
  95. GRB 060923C: NIR afterglow confirmed
  96. GRB060923C: AROMA optical obsevation
  97. GRB 060923C, optical observation
  98. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  99. GRB 060923C: VLT J-band observations
  100. GRB 060923B: Swift XRT Refined Analysis

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