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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"

18399 results found.

  1. Swift-BAT detection of GRB 050410
  2. GRB 050410: Swift XRT Position
  3. GRB 050408: Properties of the Host Galaxy
  4. GRB 050408: Swift XRT analysis
  5. GRB 050408, optical observations
  6. GRB050408: REM NIR and Optical observation
  7. GRB 050408 Optical Observations
  8. GRB 050408: Optical afterglow confirmed
  9. GRB 050408, optical observations
  10. GRB 050408 optical candidate
  11. GRB 050408: Swift XRT Position
  12. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  13. GRB 050406: early Swift XRT analysis results
  14. GRB 050406 BAT refined analysis
  15. GRB 050406: Early observations with Swift-UVOT
  16. GRB 050406: Swift XRT Position
  17. Swift-BAT detection of GRB 050406
  18. Konus-Wind observation of GRB 050401
  19. GRB050401: Radio observation at 610 MHz with GMRT
  20. GRB 050401: VLT spectroscopic redshift
  21. GRB 050401 Optical Observations
  22. GRB050401: Maidanak optical observation
  23. GRB 050401 BAT refined analysis
  24. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  25. GRB 050402A: IR Observations
  26. GRB 050402: Early observations with Swift-UVOT
  27. Swift Trigger 113225: P60 Observations
  28. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  29. GRB 050401: Optical afterglow candidate
  30. Swift-BAT detection of GRB 050401
  31. GRB 050401: Prompt XRT position
  32. Retraction of three Swift GRB triggers
  33. Swift-BAT detection of GRB 050331b
  34. GRB 050331: Swift UVOT Source
  35. Swift-BAT detection of GRB 050331
  36. GRB 050331: Swift XRT Position
  37. Swift Data Publicly Available Starting April 5, 2005
  38. Konus-Wind observation of GRB 050326
  39. GRB050326: optical limit
  40. GRB 050326: Early observations with Swift-UVOT
  41. GRB 050326 XMM-Newton observation
  42. GRB 050326 : Planned XMM-Newton observation
  43. GRB 050326: Swift XRT Position
  44. GRB050326: optical limit 33min before GRB
  45. GRB 050326 BAT refined analysis
  46. GRB050326: delayed XRT observation
  47. Swift-BAT detection of a bright GRB 050326
  48. GRB050319, optical observations
  49. GRB050319, color indices
  50. GRB050319: RTT150 Optical Observations
  51. Swift-BAT detection of a bright outburst from SGR1806-20
  52. Swift-BAT trigger 112060 is not a real GRB
  53. GRB 050319: ROTSE-III Refined Analysis
  54. GRB 050318: Swift-BAT refined analysis
  55. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  56. GRB 050319 R band observations
  57. GRB 050319: Swift-UVOT detection of the afterglow
  58. GRB 050315: Variability Analysis of Swift BAT Time History
  59. GRB050319: BR optical photometry
  60. GRB 050318: SWIFT-UVOT refined analysis
  61. GRB 050319: Swift-BAT refined analysis
  62. GRB050319,optical observation
  63. Swift Detection of GRB 050319
  64. GRB 050319: Detection of Possible Optical Counterpart
  65. GRB 050318: Swift/UVOT detection of afterglow emission
  66. GRB050318: Swift XRT position
  67. Swift-BAT detection of GRB 050318
  68. GRB050223: analysis of the XMM-Newton observation
  69. GRB 050306: ROTSE-III early limits
  70. GRB 050315: Swift-BAT further refined analysis
  71. GRB050315: Swift-BAT Refined analysis
  72. Non-detection of GRB050315 in ATCA Radio Observations
  73. GRB 050315: Swift XRT Position
  74. GRB 050315: Early Observations with Swift/UVOT
  75. Swift-BAT detection of GRB 050315
  76. GRB050223: No XMM-Newton OM detection of afterglow emission
  77. GRB050309: CONCAM pre-trigger and trigger coincident optical
  78. GRB 050126: Redshift determination
  79. Swift-BAT trigger 107873: No Swift XRT counterpart
  80. GRB 050306: Confirmation of X-ray afterglow
  81. GRB 050309, Early optical limits from RAPTOR
  82. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  83. GRB 050309 : Lulin R-band observation
  84. Swift 107873: P60 Optical Observations
  85. GRB 050306: CORRECTION to date of observation
  86. GRB 050306: No Swift UVOT Optical Counterpart Detected
  87. GRB 050306: Possible X-ray Afterglow Position from the Swift
  88. Swift trigger 107518: optical observation
  89. GRB 050306,optical observation
  90. GRB 050306: Swift-BAT detection of a long burst
  91. GRB050215B: Late-Time Swift UVOT Observations
  92. PROMPT VRcIc Observations of GRB 050223
  93. GRB 050223: optical observations
  94. GRB050223 XMM-Newton observation
  95. INTEGRAL detection of GRB 050223
  96. GRB050223: No Swift UVOT Detection of Afterglow Emission
  97. GRB050223: ROTSE-III Optical Observations
  98. GRB 050223 Swift/BAT detection of a burst
  99. GRB 050223: Swift XRT Position
  100. GRB050219b: CORRECTION to time of UVOT observations

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