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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"

19070 results found.

  1. Swift-BAT detection of GRB 050401
  2. GRB 050401: Prompt XRT position
  3. Retraction of three Swift GRB triggers
  4. Swift-BAT detection of GRB 050331b
  5. GRB 050331: Swift UVOT Source
  6. Swift-BAT detection of GRB 050331
  7. GRB 050331: Swift XRT Position
  8. Swift Data Publicly Available Starting April 5, 2005
  9. Konus-Wind observation of GRB 050326
  10. GRB050326: optical limit
  11. GRB 050326: Early observations with Swift-UVOT
  12. GRB 050326 XMM-Newton observation
  13. GRB 050326 : Planned XMM-Newton observation
  14. GRB 050326: Swift XRT Position
  15. GRB050326: optical limit 33min before GRB
  16. GRB 050326 BAT refined analysis
  17. GRB050326: delayed XRT observation
  18. Swift-BAT detection of a bright GRB 050326
  19. GRB050319, optical observations
  20. GRB050319, color indices
  21. GRB050319: RTT150 Optical Observations
  22. Swift-BAT detection of a bright outburst from SGR1806-20
  23. Swift-BAT trigger 112060 is not a real GRB
  24. GRB 050319: ROTSE-III Refined Analysis
  25. GRB 050318: Swift-BAT refined analysis
  26. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  27. GRB 050319 R band observations
  28. GRB 050319: Swift-UVOT detection of the afterglow
  29. GRB 050315: Variability Analysis of Swift BAT Time History
  30. GRB050319: BR optical photometry
  31. GRB 050318: SWIFT-UVOT refined analysis
  32. GRB 050319: Swift-BAT refined analysis
  33. GRB050319,optical observation
  34. Swift Detection of GRB 050319
  35. GRB 050319: Detection of Possible Optical Counterpart
  36. GRB 050318: Swift/UVOT detection of afterglow emission
  37. GRB050318: Swift XRT position
  38. Swift-BAT detection of GRB 050318
  39. GRB050223: analysis of the XMM-Newton observation
  40. GRB 050306: ROTSE-III early limits
  41. GRB 050315: Swift-BAT further refined analysis
  42. GRB050315: Swift-BAT Refined analysis
  43. Non-detection of GRB050315 in ATCA Radio Observations
  44. GRB 050315: Swift XRT Position
  45. GRB 050315: Early Observations with Swift/UVOT
  46. Swift-BAT detection of GRB 050315
  47. GRB050223: No XMM-Newton OM detection of afterglow emission
  48. GRB050309: CONCAM pre-trigger and trigger coincident optical
  49. GRB 050126: Redshift determination
  50. Swift-BAT trigger 107873: No Swift XRT counterpart
  51. GRB 050306: Confirmation of X-ray afterglow
  52. GRB 050309, Early optical limits from RAPTOR
  53. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  54. GRB 050309 : Lulin R-band observation
  55. Swift 107873: P60 Optical Observations
  56. GRB 050306: CORRECTION to date of observation
  57. GRB 050306: No Swift UVOT Optical Counterpart Detected
  58. GRB 050306: Possible X-ray Afterglow Position from the Swift
  59. Swift trigger 107518: optical observation
  60. GRB 050306,optical observation
  61. GRB 050306: Swift-BAT detection of a long burst
  62. GRB050215B: Late-Time Swift UVOT Observations
  63. PROMPT VRcIc Observations of GRB 050223
  64. GRB 050223: optical observations
  65. GRB050223 XMM-Newton observation
  66. INTEGRAL detection of GRB 050223
  67. GRB050223: No Swift UVOT Detection of Afterglow Emission
  68. GRB050223: ROTSE-III Optical Observations
  69. GRB 050223 Swift/BAT detection of a burst
  70. GRB 050223: Swift XRT Position
  71. GRB050219b: CORRECTION to time of UVOT observations
  72. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  73. GRB 050219b: CORRECTION to refined XRT position
  74. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  75. GRB 050219b: Refined XRT position
  76. GRB 050219b: Swift-BAT detection of a burst
  77. GRB 050219b: CORRECTION: Swift XRT Position
  78. GRB 050219b: Swift XRT Position
  79. GRB 050219a, optical observations
  80. GRB 050219a: Refined XRT position
  81. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  82. GRB 050219: Swift-BAT detection of a burst
  83. GRB050215b: Swift UVOT Detection of Afterglow Emission
  84. GRB 050219: Prompt X-ray position
  85. GRB 050215b: XRT confirmation of IR afterglow candidate
  86. GRB050215b: P60 Optical Observations
  87. GRB 050215b: Swift XRT Source Variability
  88. GRB 050215B: candidate afterglow
  89. GRB 050215b : Lulin follow-up observation
  90. GRB 050215b, BOOTES-2 simultaneous optical observations
  91. GRB 050215B: UKIRT K-band imaging
  92. GRB 050215b: Swift XRT Observations
  93. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  94. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  95. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  96. GRB050215B: ROTSE-III optical observations
  97. GRB050215A: ROTSE-III Optical Observations
  98. short/hard GRB 050202, optical observations
  99. GRB 050128: Radio observations
  100. Further analysis of the short Swift-BAT GRB 050202

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