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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"

26033 results found.

  1. GRB 061110: ROTSE-III Optical Limits
  2. GRB 061110: Swift detection of a burst
  3. GRB061110A - Optical Non-detection
  4. Swift-BAT Trigger 237821 is a Cosmic Ray Shower event
  5. GRB 061109: TAROT Calern observatory optical observations
  6. GRB 061109: Swift detection of a possible burst
  7. GRB061028: MAGIC telescope GeV observation
  8. GRB 061027: TAROT La Silla observatory optical observations
  9. GRB 061007: Third Epoch ATCA Radio Observations
  10. GRB061019: second epoch CrAO observations
  11. GRB 061028: Swift/XRT Astrometry Correction
  12. GRB 061102: Swift/UVOT Magnitude Upper Limits
  13. GRB 061102, XRT refined analysis
  14. GRB 061004: Further VLT/NTT observations
  15. Swift-BAT Trigger 236481 is a Cosmic Ray Shower event
  16. GRB061102B: Super-LOTIS observations
  17. GRB 061028: Optical R passband observations
  18. GRB 061102B: Swift detection of a possible burst
  19. GRB 061102, Swift-BAT refined analysis
  20. GRB 061102: Swift detection of a burst
  21. GRB 061028: VLA Observation
  22. GRB 061004: Swift/XRT Astrometry Correction
  23. GRB 060801: Swift/XRT Astrometry Correction
  24. GRB 061028: Futher P200 Observations
  25. GRB 061028: MDM Observations
  26. GRB 061028: P200 Observations
  27. GRB 061028: SARA upper limit
  28. GRB 061028: z band imaging
  29. GRB061028: XRT refined analysis
  30. GRB 061028: Swift/UVOT Observations
  31. GRB 061028, Swift-BAT refined analysis
  32. GRB 061028: TAROT Calern observatory late optical observations
  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: ROTSE-III Confirmation of Optical Counterpart
  38. GRB061025: Swift XRT refined analysis
  39. GRB061025: Swift/UVOT observations
  40. GRB 061019: MITSuME upper limits
  41. GRB 061025: REM observations
  42. GRB 061025: Gemini-S observations
  43. GRB061025: Swift XRT position
  44. Swift XRT boresight update
  45. GRB 061021, Swift-BAT Lag analysis
  46. Konus-Wind observation of GRB 061021
  47. GRB 061021: Swift-XRT refined analysis
  48. GRB 061021: Swift/UVOT Observation
  49. GRB 061021, Swift-BAT refined analysis
  50. GRB 061021: Swift detection of a burst
  51. GRB 061019: Super-LOTIS upper limit
  52. GRB060904b: optical observations
  53. GRB061019: optical observations
  54. GRB061019: optical observations
  55. GRB 061019: SARA upper limit
  56. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  57. GRB 061019: Swift/UVOT upper limit
  58. GRB 061019: SMARTS afterglow confirmation
  59. GRB061019: Swift XRT refined analysis
  60. GRB 061019, Swift-BAT refined analysis
  61. GRB 061019: TAROT La Silla observatory optical observations
  62. GRB 061019: REM K-band candidate afterglow
  63. GRB061019: Swift/XRT position
  64. GRB 061019: Swift-BAT detection of a burst
  65. GRB 060825: GORT Observations
  66. GRB 061007: Second Epoch ATCA Radio Observations
  67. GRB 061006: astrometry-corrected XRT position
  68. Konus-Wind observation of GRB 061007
  69. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  70. GRB 061007: ATCA Radio Observations
  71. GRB061007: Swift UVOT followup observations
  72. GRB 061006: optical afterglow
  73. GRB 061007: OA fading and VLT redshift
  74. GRB 061007: Magellan Spectroscopy
  75. GRB 061007: Correction to GCN 5712
  76. GRB 061007: Swift-BAT refined analysis
  77. GRB 061007: Swift XRT refined analysis
  78. GRB 061006: Swift/UVOT optical observations
  79. Konus-Wind observation of the short hard GRB 061006
  80. GRB 061007 - FTS early brightening and power law decay
  81. GRB 061007 - Faulkes Telescope South Afterglow Confirmation
  82. GRB 061007: Swift detection of a burst with an optical counterpart
  83. GRB 061007: ROTSE-III Detection of Optical Counterpart
  84. GRB 061006: VLT observation
  85. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  86. GRB 061006: Swift-XRT Team Refined Analysis
  87. GRB061006 (Swift 232585) might be a short-hard GRB
  88. GRB 060930: near-IR afterglow candidate retraction
  89. GRB061006: Faulkes Telescope South Observations
  90. GRB 061006: Swift detection of a burst
  91. GRB 061004: Optical afterglow candidate and redshift
  92. GRB 061004: Las Campanas Optical/NIR Observations
  93. GRB061004: Swift/UVOT optical observations
  94. GRB 061004: Swift-XRT Team Refined Analysis
  95. GRB 061004, Swift BAT refined analysis
  96. GRB 061004: Nearby 2MASS Galaxy
  97. GRB 061004: Swift detection of a burst
  98. IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
  99. GRB 060928: Swift observations
  100. IPN triangulation of GRB060928 (long, exceptionally bright)

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