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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"

14827 results found.

  1. GRB 060223B: Swift XRT possible afterglow
  2. GRB 060218/SN 2006aj: ABT observations
  3. GRB 060223A:Xinglong optical limits
  4. GRB 060223a: Swift/UVOT refined analysis
  5. GRB 060223B: Swift detection of a bright burst
  6. GRB 060223: Swift/UVOT Confirmation of Optical Afterglow
  7. GRB 060223: Swift detection of a burst
  8. GRB060218: UV Detection and Light Curves
  9. GRB 060218: optical/nIR observations at La Palma
  10. GRB 060219: Swift-BAT detection of a weak burst
  11. Brightening of the Optical Counterpart of the Possible GRB 060218
  12. GRB 060218: Pre-burst detection of a possible host galaxy
  13. GRB 060218A: ROTSE-III Possible Optical Flare
  14. Preliminary refined analysis of the Swift-BAT trigger 191157
  15. GRB 060218: Swift-BAT detection of a possible burst
  16. GRB 060213: optical afterglow candidate
  17. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  18. GRB 060206: SOAR Detections
  19. GRB 060211B: Swift-BAT detection of a burst
  20. GRB 060211: Swift detection of a long burst
  21. GRB060210:Faulkes Telescope North Afterglow Confirmation
  22. GRB 060210: Swift detection of a burst
  23. GRB 060209(?): Swift-BAT detection of a possible burst
  24. GRB060204a: Swift XRT Source is not GRB Afterglow
  25. GRB 060206: IR Detection of the Afterglow
  26. GRB 060206: Lick 3m Spectroscopy
  27. GRB060206: SARA Detection
  28. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  29. GRB060206: Swift-BAT detection of a burst
  30. BAT GRB 060204C is probably not a GRB
  31. GRB 060204B: BVRi-band detections of optical afterglow
  32. GRB060204B: Swift/UVOT refined analysis
  33. GRB060204B: Swift XRT Team Refined Analysis
  34. GRB 060204C: Liverpool Telescopes optical limit
  35. GRB 060204C: Swift-BAT detection of a burst
  36. GRB 060204B: Swift detection of a burst
  37. Swift BAT Trigger 180151: Swift XRT source detection
  38. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  39. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  40. GRB 060202: Swift detection of a burst
  41. GRB 060123: Gemini spectroscopy of the putative host galaxy
  42. GRB060130: Optical imaging
  43. GRB 060130, SMARTS optical observations
  44. GRB 060121: Probable Detection of NIR Afterglow
  45. GRB 060124: HETE detection and spectrum of the main peak
  46. GRB 060124: XRT refined analysis
  47. GRB 060123: Swift detection of a very long, faint burst
  48. GRB 060116: Further analysis of VLT photometry and optical spectroscopy
  49. GRB 060124: Confirmation of the Afterglow
  50. GRB 060124: Swift-BAT detection of a burst
  51. GRB 060116: Radio Detection
  52. GRB 060121: Infrared Observations
  53. GRB 060117: Swift-BAT detection of a bright burst
  54. GRB 060116: VLT optical observations
  55. GRB 060116: IR Candidate Afterglow
  56. GRB060116: Faulkes North observation
  57. GRB 060116: Swift-BAT detection of a burst
  58. GRB 060115: Swift detection of a burst
  59. GRB060114: Faulkes North observation
  60. GRB 060108: IR observations of afterglow
  61. GRB 060111B: MITSuME detection of optical afterglow
  62. GRB060111A: RTT150 optical observations
  63. GRB 060110: MARGE observations
  64. GRB 060111B: ROTSE-III Detection of Optical Counterpart Flare
  65. GRB 060111B: Swift detection of a burst
  66. GRB 060111: Swift detection of a burst
  67. GRB 060110a: RAPTOR detection of early optical emission.
  68. GRB 060110: IR Candidate Afterglow
  69. GRB 060110: Swift-BAT detection of a burst
  70. GRB 060108: early UKIRT K-band observations
  71. GRB 060109: Swift Detection of a long burst
  72. GRB 060108: VLT J-band observations
  73. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  74. GRB060108: Faulkes Telescope observation
  75. GRB060108: Swift detection of its 100th GRB
  76. GRB060105: Swift detection of a bright long burst
  77. GRB 060102: Swift-BAT detection of a burst
  78. GRB051227: SARA Observations
  79. GRB 051227: Likely host galaxy underlying afterglow position
  80. GRB 051227: MDM Observation
  81. GRB 051227: Swift detection of a burst
  82. GRB 051221A: Detection at 251nm with Swift UVOT
  83. GRB 051221: Redshift from Gemini
  84. Possible GRB 051221B: MDM Optical Detection
  85. GRB 051221A: RAPTOR Fading Counterpart Constraint
  86. Swift-BAT detection of a possible burst
  87. GRB 051221: Correction to GCN #4368
  88. GRB 051221: Improved astrometry of the IR counterpart
  89. GRB 051221: Swift detection of a bright short burst
  90. Refined analysis of the Swift-BAT detection of the RS CVn star II Peg
  91. Swift detection of an RS CVn flare star
  92. GRB 051215: Swift detection of a possible burst
  93. GRB 051213: Swift-BAT detection of a burst
  94. GRB051211B, RBO optical observations
  95. GRB051211B: Liverpool Telescope observation
  96. GRB 051211b: RTT150 optical observations
  97. GRB 051211B: a possible optical detection by TAROT
  98. GRB 051210: SALT detection limit
  99. GRB 051210: Swift detection of a burst
  100. GRB 051127: Swift-BAT detection of a possible burst

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