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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"

18401 results found.

  1. GRB 060109: Swift/UVOT upper limits
  2. Swift UVOT correction to GCN 4455
  3. GRB 060109: Swift Detection of a long burst
  4. GRB 060108: Refined XRT analysis
  5. GRB 060108: VLT J-band observations
  6. GRB 060108: Swift/UVOT upper limits
  7. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  8. GRB060108: Faulkes Telescope observation
  9. GRB 060108: Refined analysis of the Swift-BAT burst
  10. GRB 060108: Swift XRT position
  11. GRB060108: Swift detection of its 100th GRB
  12. GRB 060105: Radio observations
  13. Konus-Wind observation of GRB 060105
  14. GRB 060105: Swift/UVOT upper limits
  15. GRB 060105: BAT refined analysis
  16. GRB 060105: XRT refined analysis
  17. GRB060105: Swift detection of a bright long burst
  18. Swift-BAT trigger 175653 is not an astrophysical source
  19. Swift-BAT trigger 175653 is probably not a GRB
  20. GRB 060102: Swift-BAT refined analysis
  21. Time Correction to GRB 060102
  22. GRB 060102: Swift-BAT detection of a burst
  23. GRB051211B: optical observations
  24. GRB051227: SARA Observations
  25. GRB 051221B: Optical Observations with Kuiper 1.54m
  26. GRB051221B: Radio observations
  27. GRB051227: Radio Observations
  28. GRB 051227: Swift/UVOT Upper Limits (Possible U-band
  29. GRB 051227: MDM Observation
  30. GRB 051227: Joint Swift-HETE Spectral Analysis
  31. GRB 051227: XRT refined analysis
  32. GRB 051227: Further analysis of the Swift-BAT burst
  33. GRB 051227: Refined analysis of the Swift-BAT burst
  34. GRB051227: SDSS pre-burst observations
  35. GRB 051227: Swift detection of a burst
  36. Konus-Wind observation of GRB 051221A
  37. GRB051221A: Suzaku WAM observation of the prompt emission
  38. GRB051016: analysis of the XMM-Newton observation
  39. GRB 051221A: Detection at 251nm with Swift UVOT
  40. GRB 051221A: Chandra Afterglow Position
  41. GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst
  42. GRB 051221B: ROTSE-III Optical Limits
  43. GRB 051221B: TAROT optical limits
  44. GRB 051221A: WSRT Radio Observations
  45. GRB 051221B: Refined analysis of the Swift-BAT burst
  46. Possible GRB 051221B: MDM Optical Detection
  47. GRB 051221A: RAPTOR Fading Counterpart Constraint
  48. GRB 051221B: BOOTES optical observations.
  49. Possible GRB 051221B: Swift XRT position
  50. Swift-BAT detection of a possible burst
  51. GRB 051221: Swift XRT refined analysis
  52. GRB 051221: Swift/UVOT upper limits
  53. GRB 051221: XRT position
  54. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  55. GRB 051221: Swift detection of a bright short burst
  56. Refined analysis of the SWIFT J1626.6-5156
  57. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  58. Refined analysis of the Swift-BAT detection of the RS CVn star II Peg
  59. GRB 051211B: optical afterglow
  60. Swift detection of an RS CVn flare star
  61. Swift Trigger 172767 is not a GRB
  62. GRB 051215: Swift detection of a possible burst
  63. GRB 051215: A short GRB in a cluster?
  64. GRB 051213: Swift-BAT refined analysis
  65. GRB051211B: XRT refined analysis
  66. GRB 051213: Swift-BAT detection of a burst
  67. GRB 051211A: Swift/UVOT upper limits
  68. GRB 051211B: Swift/UVOT upper limits - correction
  69. GRB 051211B: Swift/UVOT upper limits
  70. GRB 051211B: Swift XRT confirmation of the afterglow
  71. GRB051211B: Liverpool Telescope observation
  72. GRB 051211B: Swift XRT Observations
  73. GRB 051210: Swift/UVOT upper limits
  74. GRB 051211: Swift XRT upper limit
  75. GRB 051210: SALT detection limit
  76. GRB 051210: BAT further refined analysis of the short burst
  77. GRB 051210: Swift XRT refined analysis
  78. GRB 051210: Swift-BAT refined analysis of a short burst
  79. GRB051210: Swift UVOT Observation
  80. GRB 051210: Swift detection of a burst
  81. IPN observations of SGR1806-20
  82. Swift XRT positions
  83. An extraordinary long burst on December 3 from SGR1806-20
  84. Swift UVOT Calibration Documentation
  85. Swift-BAT trigger 165579 is not a GRB
  86. GRB 051127: Swift-BAT detection of a possible burst
  87. GRB051117B: Swift XRT refined analysis
  88. GRB051117b: No Swift/UVOT Detection
  89. GRB 051117A: Swift/UVOT Detection of an Afterglow: Correction
  90. GRB 051117A: Swift/UVOT Detection of an Afterglow
  91. GRB051111: Rc optical observations
  92. GRB051008: Suzaku WAM observation of the prompt emission
  93. GRB 051117B: MARGE Optical Limits
  94. GRB 051117B: R and I observations of possible host galaxy
  95. GRB 051117A: Refined analysis of the Swift-BAT burst
  96. GRB 051117B: Refined analysis of the Swift-BAT burst
  97. GRB051117A : XRT refined analysis
  98. GRB 051117B,optical observation
  99. GRB 051117B: Lulin R and I band observation
  100. GRB 051117B: Optical observations

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