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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. GRB060108: P200 Ks Observations
  2. GRB 060108: early UKIRT K-band observations
  3. Swift UVOT correction to GCN 4455
  4. GRB 060109: Swift Detection of a long burst
  5. GRB 060108: a dark burst?
  6. GRB 060108: Refined XRT analysis
  7. GRB 060108: VLT J-band observations
  8. GRB 060108: Mitsume optical observations
  9. GRB 060108: Swift/UVOT upper limits
  10. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  11. GRB060108: Faulkes Telescope observation
  12. GRB 060108: Refined analysis of the Swift-BAT burst
  13. GRB 060108: Swift XRT position
  14. GRB060108: Swift detection of its 100th GRB
  15. GRB 060105: Radio observations
  16. GRB 060105: MDM Observation
  17. Konus-Wind observation of GRB 060105
  18. GRB 060105: ISAS observations and near IR upper limit
  19. GRB 060105: Swift/UVOT upper limits
  20. GRB 060105: Mitsume optical observations
  21. GRB 060105: BAT refined analysis
  22. GRB 060102 - no XRT afterglow
  23. GRB 060105: XRT refined analysis
  24. GRB060105: Swift detection of a bright long burst
  25. Swift-BAT trigger 175653 is not an astrophysical source
  26. Swift-BAT trigger 175653 is probably not a GRB
  27. GRB 060102: Swift-BAT refined analysis
  28. Time Correction to GRB 060102
  29. GRB 060102: Swift-BAT detection of a burst
  30. GRB051211B: optical observations
  31. GRB051227: SARA Observations
  32. GRB 051221B: Optical Observations with Kuiper 1.54m
  33. GRB051221B: Radio observations
  34. GRB051227: Radio Observations
  35. GRB 051227: Swift/UVOT Upper Limits (Possible U-band
  36. GRB 051227: Gemini observations
  37. GRB 051227: Keck Spectroscopy
  38. GRB 051227: Magellan r'-band Imaging/Astrometry
  39. GRB 051227: refined analysis of VLT images
  40. GRB 051227: P60 Observations
  41. GRB 051227: MDM Observation
  42. GRB 051227: R-band object in the XRT error circle
  43. GRB 051227: Joint Swift-HETE Spectral Analysis
  44. GRB 051227: XRT refined analysis
  45. GRB 051227: Further analysis of the Swift-BAT burst
  46. GRB 051227: Refined analysis of the Swift-BAT burst
  47. GRB051227: SDSS pre-burst observations
  48. GRB 051227: Swift detection of a burst
  49. Konus-Wind observation of GRB 051221A
  50. GRB051221A: Suzaku WAM observation of the prompt emission
  51. GRB051016: analysis of the XMM-Newton observation
  52. GRB 051221A: Detection at 251nm with Swift UVOT
  53. GRB 051221A: Chandra Afterglow Position
  54. GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst
  55. GRB 051221B: ROTSE-III Optical Limits
  56. GRB 051221B: TAROT optical limits
  57. GRB 051221A: WSRT Radio Observations
  58. GRB 051221B: Refined analysis of the Swift-BAT burst
  59. Possible GRB 051221B: MDM Optical Detection
  60. GRB 051221A: RAPTOR Fading Counterpart Constraint
  61. GRB 051221B: BOOTES optical observations.
  62. Possible GRB 051221B: Swift XRT position
  63. Swift-BAT detection of a possible burst
  64. GRB 051221: Discovery of fading optical afterglow
  65. GRB 051221: Swift XRT refined analysis
  66. GRB 051221: Swift/UVOT upper limits
  67. GRB 051221: No variability in Gemini data
  68. GRB 051221: Gemini observations
  69. GRB 051221: Improved astrometry of the IR counterpart
  70. GRB051221: K-band source
  71. GRB 051221: XRT position
  72. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  73. GRB 051221: Swift detection of a bright short burst
  74. Refined analysis of the SWIFT J1626.6-5156
  75. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  76. Refined analysis of the Swift-BAT detection of the RS CVn star II Peg
  77. GRB 051211B: optical afterglow
  78. Swift detection of an RS CVn flare star
  79. Swift Trigger 172767 is not a GRB
  80. GRB 051215: Swift detection of a possible burst
  81. GRB 051215: A short GRB in a cluster?
  82. GRB051211B: Probable radio afterglow
  83. GRB051105: optical observations
  84. GRB 051213: Swift-BAT refined analysis
  85. GRB051211B: XRT refined analysis
  86. GRB 051213: Swift-BAT detection of a burst
  87. GRB 051211A: Swift/UVOT upper limits
  88. GRB 051211B: Swift/UVOT upper limits - correction
  89. GRB 051211B: Swift/UVOT upper limits
  90. GRB 051211B: Swift XRT confirmation of the afterglow
  91. GRB051211B: Liverpool Telescope observation
  92. GRB 051211b: RTT150 optical observations
  93. GRB051211b: P60 Observations
  94. GRB 051211B: Swift XRT Observations
  95. GRB 051210: Swift/UVOT upper limits
  96. GRB 051211: Swift XRT upper limit
  97. GRB 051210: Optical imaging from Las Campanas
  98. GRB 051210: SALT detection limit
  99. GRB 051210: BAT further refined analysis of the short burst
  100. GRB 051210: Swift XRT refined analysis

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