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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"

19185 results found.

  1. GRB061202 optical limit by "Pi of the Sky"
  2. Konus-Wind observation of GRB 061201
  3. GRB061202: Swift/UVOT Upper Limits
  4. GRB 061202, Swift-BAT refined analysis
  5. GRB 061202: Swift detection of a burst
  6. GRB 061201: Swift XRT Team refined analysis
  7. GRB 061201: Initial UVOT Observations
  8. GRB 061201, Swift-BAT refined analysis of the SHB
  9. GRB 061201: Swift detection of a short hard burst
  10. GRB 061201: Coincidence with a Galaxy Cluster
  11. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  12. Swift XRT on-board boresight update
  13. GRB 061126: Early Super-LOTIS Observations
  14. GRB061126: Optical afterglow observations from MIRO
  15. GRB061126: Optical afterglow observations from MIRO
  16. GRB 061126: Swift-XRT refined analysis
  17. GRB 061126: Swift/UVOT Observations
  18. GRB 061126, Swift-BAT refined analysis
  19. GRB 061126: Faulkes Telescope North Optical Observations
  20. GRB 061126: Swift/UVOT Afterglow Detection
  21. GRB 061126: XRT position
  22. GRB 061126: Swift detection of a burst
  23. GRB 061122: Confirmation of X-ray/Optical Afterglow
  24. GRB 061122: Candidate Optical Afterglow
  25. GRB 061121: Ep,i - Eiso correlation
  26. GRB061122: Swift/UVOT Optical Observations
  27. GRB061122: Swift-XRT position
  28. GRB 061121 declared "Burst of Interest" by Swift team
  29. Konus-Wind and Konus-A observations of GRB 061121
  30. Swift-BAT trigger 239987 is not a GRB
  31. GRB 061121: Swift/UVOT Observations
  32. GRB 061121: Swift-XRT Team Refined Analysis
  33. GRB 061121, Swift-BAT refined analysis
  34. GRB061121, optical observation
  35. GRB 061121: Faulkes Telescope North Optical Observation
  36. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  37. GRB 061121: Swift detection of a bright burst with an optical counterpart
  38. GRB 060111B: Swift UVOT Refined Magnitudes
  39. Swift-BAT triggers 238544 and 238546 are not GRBs
  40. Swift TOO observations of GRB061110A
  41. Swift/UVOT Upper Limits for GRB061110b
  42. Swift/UVOT Upper Limits for GRB061110a
  43. GRB 061110B: Swift XRT refined analysis
  44. GRB 061110B, Swift-BAT refined analysis
  45. GRB061110B: Optical observations at Crni Vrh
  46. GRB 061110A: Swift XRT refined analysis
  47. GRB 061110B: Swift/XRT position
  48. GRB 061110B: Swift-UVOT Initial Observation
  49. GRB 061110A, Swift-BAT refined analysis
  50. GRB 061110B: TAROT Calern observatory optical observations
  51. GRB 061110B: Swift detection of a burst
  52. GRB 061110: ROTSE-III Optical Limits
  53. GRB 061110: Swift detection of a burst
  54. Swift-BAT Trigger 237821 is a Cosmic Ray Shower event
  55. GRB 061109: TAROT Calern observatory optical observations
  56. GRB 061109: Swift detection of a possible burst
  57. GRB061028: MAGIC telescope GeV observation
  58. GRB 061027: TAROT La Silla observatory optical observations
  59. GRB 061028: Swift/XRT Astrometry Correction
  60. GRB 061102: Swift/UVOT Magnitude Upper Limits
  61. GRB 061102, XRT refined analysis
  62. Swift-BAT Trigger 236481 is a Cosmic Ray Shower event
  63. GRB061102B: Super-LOTIS observations
  64. GRB 061028: Optical R passband observations
  65. GRB 061102B: Swift detection of a possible burst
  66. GRB 061102, Swift-BAT refined analysis
  67. GRB 061102: Swift detection of a burst
  68. GRB 061028: VLA Observation
  69. GRB 061004: Swift/XRT Astrometry Correction
  70. GRB 060801: Swift/XRT Astrometry Correction
  71. GRB 061028: MDM Observations
  72. GRB 061028: SARA upper limit
  73. GRB061028: XRT refined analysis
  74. GRB 061028: Swift/UVOT Observations
  75. GRB 061028, Swift-BAT refined analysis
  76. GRB 061028: TAROT Calern observatory optical observations
  77. GRB 061028: Swift detection of a burst
  78. GRB 061027, Swift refined analysis of a possible burst
  79. GRB 061027: Swift detection of a possible burst
  80. GRB061025: Swift XRT refined analysis
  81. GRB061025: Swift/UVOT observations
  82. GRB061025: Swift XRT position
  83. Swift XRT boresight update
  84. GRB 061021, Swift-BAT Lag analysis
  85. Konus-Wind observation of GRB 061021
  86. GRB 061021: Swift-XRT refined analysis
  87. GRB 061021: Swift/UVOT Observation
  88. GRB 061021, Swift-BAT refined analysis
  89. GRB 061021: Swift detection of a burst
  90. GRB 061019: Super-LOTIS upper limit
  91. GRB 061019: SARA upper limit
  92. GRB 061019: dust-scattered X-ray halo detected in Swift/XRT
  93. GRB 061019: Swift/UVOT upper limit
  94. GRB061019: Swift XRT refined analysis
  95. GRB 061019, Swift-BAT refined analysis
  96. GRB 061019: TAROT La Silla observatory optical observations
  97. GRB061019: Swift/XRT position
  98. GRB 061019: Swift-BAT detection of a burst
  99. GRB 061006: astrometry-corrected XRT position
  100. Konus-Wind observation of GRB 061007

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