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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"

18676 results found.

  1. GRB 061201: Coincidence with a Galaxy Cluster
  2. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  3. Swift XRT on-board boresight update
  4. GRB 061126: Early Super-LOTIS Observations
  5. GRB061126: Optical afterglow observations from MIRO
  6. GRB061126: Optical afterglow observations from MIRO
  7. GRB 061126: Swift-XRT refined analysis
  8. GRB 061126: Swift/UVOT Observations
  9. GRB 061126, Swift-BAT refined analysis
  10. GRB 061126: Faulkes Telescope North Optical Observations
  11. GRB 061126: Swift/UVOT Afterglow Detection
  12. GRB 061126: XRT position
  13. GRB 061126: Swift detection of a burst
  14. GRB 061122: Confirmation of X-ray/Optical Afterglow
  15. GRB 061122: Candidate Optical Afterglow
  16. GRB 061121: Ep,i - Eiso correlation
  17. GRB061122: Swift/UVOT Optical Observations
  18. GRB061122: Swift-XRT position
  19. GRB 061121 declared "Burst of Interest" by Swift team
  20. Konus-Wind and Konus-A observations of GRB 061121
  21. Swift-BAT trigger 239987 is not a GRB
  22. GRB 061121: Swift/UVOT Observations
  23. GRB 061121: Swift-XRT Team Refined Analysis
  24. GRB 061121, Swift-BAT refined analysis
  25. GRB061121, optical observation
  26. GRB 061121: Faulkes Telescope North Optical Observation
  27. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  28. GRB 061121: Swift detection of a bright burst with an optical counterpart
  29. GRB 060111B: Swift UVOT Refined Magnitudes
  30. Swift-BAT triggers 238544 and 238546 are not GRBs
  31. Swift TOO observations of GRB061110A
  32. Swift/UVOT Upper Limits for GRB061110b
  33. Swift/UVOT Upper Limits for GRB061110a
  34. GRB 061110B: Swift XRT refined analysis
  35. GRB 061110B, Swift-BAT refined analysis
  36. GRB061110B: Optical observations at Crni Vrh
  37. GRB 061110A: Swift XRT refined analysis
  38. GRB 061110B: Swift/XRT position
  39. GRB 061110B: Swift-UVOT Initial Observation
  40. GRB 061110A, Swift-BAT refined analysis
  41. GRB 061110B: TAROT Calern observatory optical observations
  42. GRB 061110B: Swift detection of a burst
  43. GRB 061110: ROTSE-III Optical Limits
  44. GRB 061110: Swift detection of a burst
  45. Swift-BAT Trigger 237821 is a Cosmic Ray Shower event
  46. GRB 061109: TAROT Calern observatory optical observations
  47. GRB 061109: Swift detection of a possible burst
  48. GRB061028: MAGIC telescope GeV observation
  49. GRB 061027: TAROT La Silla observatory optical observations
  50. GRB 061028: Swift/XRT Astrometry Correction
  51. GRB 061102: Swift/UVOT Magnitude Upper Limits
  52. GRB 061102, XRT refined analysis
  53. Swift-BAT Trigger 236481 is a Cosmic Ray Shower event
  54. GRB061102B: Super-LOTIS observations
  55. GRB 061028: Optical R passband observations
  56. GRB 061102B: Swift detection of a possible burst
  57. GRB 061102, Swift-BAT refined analysis
  58. GRB 061102: Swift detection of a burst
  59. GRB 061028: VLA Observation
  60. GRB 061004: Swift/XRT Astrometry Correction
  61. GRB 060801: Swift/XRT Astrometry Correction
  62. GRB 061028: MDM Observations
  63. GRB 061028: SARA upper limit
  64. GRB061028: XRT refined analysis
  65. GRB 061028: Swift/UVOT Observations
  66. GRB 061028, Swift-BAT refined analysis
  67. GRB 061028: TAROT Calern observatory optical observations
  68. GRB 061028: Swift detection of a burst
  69. GRB 061027, Swift refined analysis of a possible burst
  70. GRB 061027: Swift detection of a possible burst
  71. GRB061025: Swift XRT refined analysis
  72. GRB061025: Swift/UVOT observations
  73. GRB061025: Swift XRT position
  74. Swift XRT boresight update
  75. GRB 061021, Swift-BAT Lag analysis
  76. Konus-Wind observation of GRB 061021
  77. GRB 061021: Swift-XRT refined analysis
  78. GRB 061021: Swift/UVOT Observation
  79. GRB 061021, Swift-BAT refined analysis
  80. GRB 061021: Swift detection of a burst
  81. GRB 061019: Super-LOTIS upper limit
  82. GRB 061019: SARA upper limit
  83. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  84. GRB 061019: Swift/UVOT upper limit
  85. GRB061019: Swift XRT refined analysis
  86. GRB 061019, Swift-BAT refined analysis
  87. GRB 061019: TAROT La Silla observatory optical observations
  88. GRB061019: Swift/XRT position
  89. GRB 061019: Swift-BAT detection of a burst
  90. GRB 061006: astrometry-corrected XRT position
  91. Konus-Wind observation of GRB 061007
  92. GRB 060928: Confirmation of the X-ray afterglow detected by Swift
  93. GRB061007: Swift UVOT followup observations
  94. GRB 061007: Magellan Spectroscopy
  95. GRB 061007: Correction to GCN 5712
  96. GRB 061007: Swift-BAT refined analysis
  97. GRB 061007: Swift XRT refined analysis
  98. GRB 061006: Swift/UVOT optical observations
  99. Konus-Wind observation of the short hard GRB 061006
  100. GRB 061007 - Faulkes Telescope South Afterglow Confirmation

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