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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"

21467 results found.

  1. GRB 061122: Candidate Optical Afterglow
  2. GRB 061121: Ep,i - Eiso correlation
  3. GRB061122: Swift/UVOT Optical Observations
  4. GRB061122: Swift-XRT position
  5. GRB 061121 declared "Burst of Interest" by Swift team
  6. Konus-Wind and Konus-A observations of GRB 061121
  7. Swift-BAT trigger 239987 is not a GRB
  8. GRB 061121: Swift/UVOT Observations
  9. GRB 061121: Swift-XRT Team Refined Analysis
  10. GRB 061121, Swift-BAT refined analysis
  11. GRB061121, optical observation
  12. GRB 061121: Faulkes Telescope North Optical Observation
  13. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  14. GRB 061121: Swift detection of a bright burst with an optical counterpart
  15. GRB 050915B: optical afterglow
  16. GRB 060111B: Swift UVOT Refined Magnitudes
  17. Swift-BAT triggers 238544 and 238546 are not GRBs
  18. GRB 061110B: NIR Observations
  19. Swift TOO observations of GRB061110A
  20. Swift/UVOT Upper Limits for GRB061110b
  21. Swift/UVOT Upper Limits for GRB061110a
  22. GRB 061110B: Swift XRT refined analysis
  23. GRB 061110B, Swift-BAT refined analysis
  24. GRB061110B: Optical observations at Crni Vrh
  25. GRB 061110A: Swift XRT refined analysis
  26. GRB 061110B: Swift/XRT position
  27. GRB 061110B: Swift-UVOT Initial Observation
  28. GRB 061110A, Swift-BAT refined analysis
  29. GRB 061110B: TAROT Calern observatory optical observations
  30. GRB 061110B: Swift detection of a burst
  31. GRB 061110: Candidate confirmed
  32. GRB 061110: ROTSE-III Optical Limits
  33. GRB 061110: Swift detection of a burst
  34. GRB061110A - Optical Non-detection
  35. Swift-BAT Trigger 237821 is a Cosmic Ray Shower event
  36. GRB 061109: TAROT Calern observatory optical observations
  37. GRB 061109: Swift detection of a possible burst
  38. GRB061028: MAGIC telescope GeV observation
  39. GRB 061027: TAROT La Silla observatory optical observations
  40. GRB061019: second epoch CrAO observations
  41. GRB 061028: Swift/XRT Astrometry Correction
  42. GRB 061102: Swift/UVOT Magnitude Upper Limits
  43. GRB 061102, XRT refined analysis
  44. GRB 061004: Further VLT/NTT observations
  45. Swift-BAT Trigger 236481 is a Cosmic Ray Shower event
  46. GRB061102B: Super-LOTIS observations
  47. GRB 061028: Optical R passband observations
  48. GRB 061102B: Swift detection of a possible burst
  49. GRB 061102, Swift-BAT refined analysis
  50. GRB 061102: Swift detection of a burst
  51. GRB 061028: VLA Observation
  52. GRB 061004: Swift/XRT Astrometry Correction
  53. GRB 060801: Swift/XRT Astrometry Correction
  54. GRB 061028: MDM Observations
  55. GRB 061028: P200 Observations
  56. GRB 061028: SARA upper limit
  57. GRB 061028: z band imaging
  58. GRB061028: XRT refined analysis
  59. GRB 061028: Swift/UVOT Observations
  60. GRB 061028, Swift-BAT refined analysis
  61. GRB 061028: TAROT Calern observatory late optical observations
  62. GRB 061028: TAROT Calern observatory optical observations
  63. GRB 061028: Swift detection of a burst
  64. GRB 061027, Swift refined analysis of a possible burst
  65. GRB 061027: Swift detection of a possible burst
  66. GRB061025: ROTSE-III Confirmation of Optical Counterpart
  67. GRB061025: Swift XRT refined analysis
  68. GRB061025: Swift/UVOT observations
  69. GRB 061019: MITSuME upper limits
  70. GRB 061025: REM observations
  71. GRB 061025: Gemini-S observations
  72. GRB061025: Swift XRT position
  73. Swift XRT boresight update
  74. GRB 061021, Swift-BAT Lag analysis
  75. Konus-Wind observation of GRB 061021
  76. GRB 061021: Swift-XRT refined analysis
  77. GRB 061021: Swift/UVOT Observation
  78. GRB 061021, Swift-BAT refined analysis
  79. GRB 061021: Swift detection of a burst
  80. GRB 061019: Super-LOTIS upper limit
  81. GRB061019: optical observations
  82. GRB061019: optical observations
  83. GRB 061019: SARA upper limit
  84. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  85. GRB 061019: Swift/UVOT upper limit
  86. GRB061019: Swift XRT refined analysis
  87. GRB 061019, Swift-BAT refined analysis
  88. GRB 061019: TAROT La Silla observatory optical observations
  89. GRB061019: Swift/XRT position
  90. GRB 061019: Swift-BAT detection of a burst
  91. GRB 060825: GORT Observations
  92. GRB 061006: astrometry-corrected XRT position
  93. Konus-Wind observation of GRB 061007
  94. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  95. GRB061007: Swift UVOT followup observations
  96. GRB 061006: optical afterglow
  97. GRB 061007: Magellan Spectroscopy
  98. GRB 061007: Correction to GCN 5712
  99. GRB 061007: Swift-BAT refined analysis
  100. GRB 061007: Swift XRT refined analysis

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