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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"

18396 results found.

  1. GRB 050408: Swift XRT analysis
  2. GRB 050408, optical observations
  3. GRB050408: REM NIR and Optical observation
  4. GRB 050408 Optical Observations
  5. GRB 050408: Optical afterglow confirmed
  6. GRB 050408, optical observations
  7. GRB 050408 optical candidate
  8. GRB 050408: Swift XRT Position
  9. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  10. GRB 050406: early Swift XRT analysis results
  11. GRB 050406 BAT refined analysis
  12. GRB 050406: Early observations with Swift-UVOT
  13. GRB 050406: Swift XRT Position
  14. Swift-BAT detection of GRB 050406
  15. Konus-Wind observation of GRB 050401
  16. GRB050401: Radio observation at 610 MHz with GMRT
  17. GRB 050401: VLT spectroscopic redshift
  18. GRB 050401 Optical Observations
  19. GRB050401: Maidanak optical observation
  20. GRB 050401 BAT refined analysis
  21. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  22. GRB 050402A: IR Observations
  23. GRB 050402: Early observations with Swift-UVOT
  24. Swift Trigger 113225: P60 Observations
  25. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  26. GRB 050401: Optical afterglow candidate
  27. Swift-BAT detection of GRB 050401
  28. GRB 050401: Prompt XRT position
  29. Retraction of three Swift GRB triggers
  30. Swift-BAT detection of GRB 050331b
  31. GRB 050331: Swift UVOT Source
  32. Swift-BAT detection of GRB 050331
  33. GRB 050331: Swift XRT Position
  34. Swift Data Publicly Available Starting April 5, 2005
  35. Konus-Wind observation of GRB 050326
  36. GRB050326: optical limit
  37. GRB 050326: Early observations with Swift-UVOT
  38. GRB 050326 XMM-Newton observation
  39. GRB 050326 : Planned XMM-Newton observation
  40. GRB 050326: Swift XRT Position
  41. GRB050326: optical limit 33min before GRB
  42. GRB 050326 BAT refined analysis
  43. GRB050326: delayed XRT observation
  44. Swift-BAT detection of a bright GRB 050326
  45. GRB050319, optical observations
  46. GRB050319, color indices
  47. GRB050319: RTT150 Optical Observations
  48. Swift-BAT detection of a bright outburst from SGR1806-20
  49. Swift-BAT trigger 112060 is not a real GRB
  50. GRB 050319: ROTSE-III Refined Analysis
  51. GRB 050318: Swift-BAT refined analysis
  52. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  53. GRB 050319 R band observations
  54. GRB 050319: Swift-UVOT detection of the afterglow
  55. GRB 050315: Variability Analysis of Swift BAT Time History
  56. GRB050319: BR optical photometry
  57. GRB 050318: SWIFT-UVOT refined analysis
  58. GRB 050319: Swift-BAT refined analysis
  59. GRB050319,optical observation
  60. Swift Detection of GRB 050319
  61. GRB 050319: Detection of Possible Optical Counterpart
  62. GRB 050318: Swift/UVOT detection of afterglow emission
  63. GRB050318: Swift XRT position
  64. Swift-BAT detection of GRB 050318
  65. GRB050223: analysis of the XMM-Newton observation
  66. GRB 050306: ROTSE-III early limits
  67. GRB 050315: Swift-BAT further refined analysis
  68. GRB050315: Swift-BAT Refined analysis
  69. Non-detection of GRB050315 in ATCA Radio Observations
  70. GRB 050315: Swift XRT Position
  71. GRB 050315: Early Observations with Swift/UVOT
  72. Swift-BAT detection of GRB 050315
  73. GRB050223: No XMM-Newton OM detection of afterglow emission
  74. GRB050309: CONCAM pre-trigger and trigger coincident optical
  75. GRB 050126: Redshift determination
  76. Swift-BAT trigger 107873: No Swift XRT counterpart
  77. GRB 050306: Confirmation of X-ray afterglow
  78. GRB 050309, Early optical limits from RAPTOR
  79. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  80. GRB 050309 : Lulin R-band observation
  81. Swift 107873: P60 Optical Observations
  82. GRB 050306: CORRECTION to date of observation
  83. GRB 050306: No Swift UVOT Optical Counterpart Detected
  84. GRB 050306: Possible X-ray Afterglow Position from the Swift
  85. Swift trigger 107518: optical observation
  86. GRB 050306,optical observation
  87. GRB 050306: Swift-BAT detection of a long burst
  88. GRB050215B: Late-Time Swift UVOT Observations
  89. PROMPT VRcIc Observations of GRB 050223
  90. GRB 050223: optical observations
  91. GRB050223 XMM-Newton observation
  92. INTEGRAL detection of GRB 050223
  93. GRB050223: No Swift UVOT Detection of Afterglow Emission
  94. GRB050223: ROTSE-III Optical Observations
  95. GRB 050223 Swift/BAT detection of a burst
  96. GRB 050223: Swift XRT Position
  97. GRB050219b: CORRECTION to time of UVOT observations
  98. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  99. GRB 050219b: CORRECTION to refined XRT position
  100. GRB050219b: No Swift UVOT Detection of Afterglow Emission

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