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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"

21392 results found.

  1. GRB 061021: Swift-XRT refined analysis
  2. GRB 061021: Swift/UVOT Observation
  3. GRB 061021, Swift-BAT refined analysis
  4. GRB 061021: Swift detection of a burst
  5. GRB 061019: Super-LOTIS upper limit
  6. GRB061019: optical observations
  7. GRB061019: optical observations
  8. GRB 061019: SARA upper limit
  9. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  10. GRB 061019: Swift/UVOT upper limit
  11. GRB061019: Swift XRT refined analysis
  12. GRB 061019, Swift-BAT refined analysis
  13. GRB 061019: TAROT La Silla observatory optical observations
  14. GRB061019: Swift/XRT position
  15. GRB 061019: Swift-BAT detection of a burst
  16. GRB 060825: GORT Observations
  17. GRB 061006: astrometry-corrected XRT position
  18. Konus-Wind observation of GRB 061007
  19. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  20. GRB061007: Swift UVOT followup observations
  21. GRB 061006: optical afterglow
  22. GRB 061007: Magellan Spectroscopy
  23. GRB 061007: Correction to GCN 5712
  24. GRB 061007: Swift-BAT refined analysis
  25. GRB 061007: Swift XRT refined analysis
  26. GRB 061006: Swift/UVOT optical observations
  27. Konus-Wind observation of the short hard GRB 061006
  28. GRB 061007 - Faulkes Telescope South Afterglow Confirmation
  29. GRB 061007: Swift detection of a burst with an optical counterpart
  30. GRB 061007: ROTSE-III Detection of Optical Counterpart
  31. GRB 061006: VLT observation
  32. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  33. GRB 061006: Swift-XRT Team Refined Analysis
  34. GRB061006 (Swift 232585) might be a short-hard GRB
  35. GRB061006: Faulkes Telescope South Observations
  36. GRB 061006: Swift detection of a burst
  37. GRB 061004: Optical afterglow candidate and redshift
  38. GRB 061004: Las Campanas Optical/NIR Observations
  39. GRB061004: Swift/UVOT optical observations
  40. GRB 061004: Swift-XRT Team Refined Analysis
  41. GRB 061004, Swift BAT refined analysis
  42. GRB 061004: Nearby 2MASS Galaxy
  43. GRB 061004: Swift detection of a burst
  44. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  45. GRB 060928: Swift observations
  46. IPN triangulation of GRB060928 (long, exceptionally bright)
  47. GRB061002: Swift UVOT followup observations
  48. GRB 061002: Swift-XRT Team Refined Analysis
  49. GRB 061002, Swift-BAT refined analysis
  50. GRB061002: MASTER-VWF-Kislovodsk observations
  51. GRB 061002: Swift detection of a burst: CORRECTED CONTENT
  52. GRB 061002: Swift detection of a burst
  53. GRB 060929: Further XRT Refined Analysis
  54. GRB 060929: Swift/UVOT Optical Observations
  55. GRB060929: Swift-XRT refined analysis.
  56. GRB 060929, Swift-BAT further refined analysis - late-time flare
  57. GRB 060929: TNG K-band observations
  58. GRB 060929, Swift-BAT refined analysis
  59. GRB060929: Optical limit
  60. GRB 060929: BART observation
  61. GRB 060929: MASTER-VWF-Kislovodsk observations
  62. GRB 060929: BOOTES-IR & OSN observations
  63. Liverpool Telescope observations of GRB 060929
  64. GRB 060929: Swift detection of a burst
  65. GRB 060729: An update on the late-time Swift observations
  66. GRB 060926: Swift-UVOT UVW1 Detection Retraction
  67. GRB 060927: pseudo-z from spectral parameters of the prompt emission
  68. GRB 060927: Swift/UVOT Optical Observations
  69. GRB 060927: Swift XRT Team refined analysis
  70. GRB 060927, Swift-BAT refined analysis
  71. GRB 060927 : Kiso optical observation
  72. GRB060927: Faulkes Telescope South observation
  73. GRB060927 - SDSS Pre-Burst Observations
  74. GRB 060927A: ROTSE-III Detection of Optical Counterpart
  75. Swift XRT boresight
  76. GRB 060927: Swift detection of a burst
  77. GRB060926: VLT redshift
  78. GRB 060926: Swift-UVOT Detections
  79. GRB 060926: Swift XRT refined analysis
  80. GRB 060926, Swift-BAT refined analysis
  81. GRB 060926: RTT150, UVOT afterglow candidate confirmation
  82. GRB 060926: BOOTES-IR observations
  83. GRB060926 OPTIMA-Burst optical observation
  84. GRB 060926: Swift detection of a burst
  85. GRB 060923C, Swift-BAT refined analysis
  86. GRB 060923C: VLA Observation
  87. GRB 060923C: Gemini Observations and Afterglow Candidate
  88. GRB 060923A: Gemini Second Epoch and Afterglow Confirmation
  89. GRB 060923C: VLT J-band observations
  90. GRB060923B: Swift/UVOT upper limits
  91. GRB 060923B: Swift XRT Refined Analysis
  92. GRB 060923C: Swift XRT refined analysis
  93. GRB 060923C, Swift-BAT partial refined analysis
  94. GRB 060923A: Swift XRT refined analysis
  95. GRB 060923C: Keck Observations
  96. GRB 060923A: Keck and Gemini Observations
  97. GRB 060923B, Swift-BAT refined analysis
  98. GRB060923C : Faulkes Telescope South optical limits
  99. GRB060923C: Faulkes Telescope North optical observations
  100. GRB 060923C: Swift detection of a burst

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