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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"

21455 results found.

  1. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  2. GRB 061121: Swift detection of a bright burst with an optical counterpart
  3. GRB 050915B: optical afterglow
  4. GRB 060111B: Swift UVOT Refined Magnitudes
  5. Swift-BAT triggers 238544 and 238546 are not GRBs
  6. GRB 061110B: NIR Observations
  7. Swift TOO observations of GRB061110A
  8. Swift/UVOT Upper Limits for GRB061110b
  9. Swift/UVOT Upper Limits for GRB061110a
  10. GRB 061110B: Swift XRT refined analysis
  11. GRB 061110B, Swift-BAT refined analysis
  12. GRB061110B: Optical observations at Crni Vrh
  13. GRB 061110A: Swift XRT refined analysis
  14. GRB 061110B: Swift/XRT position
  15. GRB 061110B: Swift-UVOT Initial Observation
  16. GRB 061110A, Swift-BAT refined analysis
  17. GRB 061110B: TAROT Calern observatory optical observations
  18. GRB 061110B: Swift detection of a burst
  19. GRB 061110: Candidate confirmed
  20. GRB 061110: ROTSE-III Optical Limits
  21. GRB 061110: Swift detection of a burst
  22. GRB061110A - Optical Non-detection
  23. Swift-BAT Trigger 237821 is a Cosmic Ray Shower event
  24. GRB 061109: TAROT Calern observatory optical observations
  25. GRB 061109: Swift detection of a possible burst
  26. GRB061028: MAGIC telescope GeV observation
  27. GRB 061027: TAROT La Silla observatory optical observations
  28. GRB061019: second epoch CrAO observations
  29. GRB 061028: Swift/XRT Astrometry Correction
  30. GRB 061102: Swift/UVOT Magnitude Upper Limits
  31. GRB 061102, XRT refined analysis
  32. GRB 061004: Further VLT/NTT observations
  33. Swift-BAT Trigger 236481 is a Cosmic Ray Shower event
  34. GRB061102B: Super-LOTIS observations
  35. GRB 061028: Optical R passband observations
  36. GRB 061102B: Swift detection of a possible burst
  37. GRB 061102, Swift-BAT refined analysis
  38. GRB 061102: Swift detection of a burst
  39. GRB 061028: VLA Observation
  40. GRB 061004: Swift/XRT Astrometry Correction
  41. GRB 060801: Swift/XRT Astrometry Correction
  42. GRB 061028: MDM Observations
  43. GRB 061028: P200 Observations
  44. GRB 061028: SARA upper limit
  45. GRB 061028: z band imaging
  46. GRB061028: XRT refined analysis
  47. GRB 061028: Swift/UVOT Observations
  48. GRB 061028, Swift-BAT refined analysis
  49. GRB 061028: TAROT Calern observatory late optical observations
  50. GRB 061028: TAROT Calern observatory optical observations
  51. GRB 061028: Swift detection of a burst
  52. GRB 061027, Swift refined analysis of a possible burst
  53. GRB 061027: Swift detection of a possible burst
  54. GRB061025: ROTSE-III Confirmation of Optical Counterpart
  55. GRB061025: Swift XRT refined analysis
  56. GRB061025: Swift/UVOT observations
  57. GRB 061019: MITSuME upper limits
  58. GRB 061025: REM observations
  59. GRB 061025: Gemini-S observations
  60. GRB061025: Swift XRT position
  61. Swift XRT boresight update
  62. GRB 061021, Swift-BAT Lag analysis
  63. Konus-Wind observation of GRB 061021
  64. GRB 061021: Swift-XRT refined analysis
  65. GRB 061021: Swift/UVOT Observation
  66. GRB 061021, Swift-BAT refined analysis
  67. GRB 061021: Swift detection of a burst
  68. GRB 061019: Super-LOTIS upper limit
  69. GRB061019: optical observations
  70. GRB061019: optical observations
  71. GRB 061019: SARA upper limit
  72. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  73. GRB 061019: Swift/UVOT upper limit
  74. GRB061019: Swift XRT refined analysis
  75. GRB 061019, Swift-BAT refined analysis
  76. GRB 061019: TAROT La Silla observatory optical observations
  77. GRB061019: Swift/XRT position
  78. GRB 061019: Swift-BAT detection of a burst
  79. GRB 060825: GORT Observations
  80. GRB 061006: astrometry-corrected XRT position
  81. Konus-Wind observation of GRB 061007
  82. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  83. GRB061007: Swift UVOT followup observations
  84. GRB 061006: optical afterglow
  85. GRB 061007: Magellan Spectroscopy
  86. GRB 061007: Correction to GCN 5712
  87. GRB 061007: Swift-BAT refined analysis
  88. GRB 061007: Swift XRT refined analysis
  89. GRB 061006: Swift/UVOT optical observations
  90. Konus-Wind observation of the short hard GRB 061006
  91. GRB 061007 - Faulkes Telescope South Afterglow Confirmation
  92. GRB 061007: Swift detection of a burst with an optical counterpart
  93. GRB 061007: ROTSE-III Detection of Optical Counterpart
  94. GRB 061006: VLT observation
  95. GRB 061006: Swift-BAT refined analysis of the short-hard burst
  96. GRB 061006: Swift-XRT Team Refined Analysis
  97. GRB061006 (Swift 232585) might be a short-hard GRB
  98. GRB061006: Faulkes Telescope South Observations
  99. GRB 061006: Swift detection of a burst
  100. GRB 061004: Optical afterglow candidate and redshift

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