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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"

18695 results found.

  1. GRB 050401: Optical afterglow candidate
  2. Swift-BAT detection of GRB 050401
  3. GRB 050401: Prompt XRT position
  4. Retraction of three Swift GRB triggers
  5. Swift-BAT detection of GRB 050331b
  6. GRB 050331: Swift UVOT Source
  7. Swift-BAT detection of GRB 050331
  8. GRB 050331: Swift XRT Position
  9. Swift Data Publicly Available Starting April 5, 2005
  10. Konus-Wind observation of GRB 050326
  11. GRB050326: optical limit
  12. GRB 050326: Early observations with Swift-UVOT
  13. GRB 050326 XMM-Newton observation
  14. GRB 050326 : Planned XMM-Newton observation
  15. GRB 050326: Swift XRT Position
  16. GRB050326: optical limit 33min before GRB
  17. GRB 050326 BAT refined analysis
  18. GRB050326: delayed XRT observation
  19. Swift-BAT detection of a bright GRB 050326
  20. GRB050319, optical observations
  21. GRB050319, color indices
  22. GRB050319: RTT150 Optical Observations
  23. Swift-BAT detection of a bright outburst from SGR1806-20
  24. Swift-BAT trigger 112060 is not a real GRB
  25. GRB 050319: ROTSE-III Refined Analysis
  26. GRB 050318: Swift-BAT refined analysis
  27. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  28. GRB 050319 R band observations
  29. GRB 050319: Swift-UVOT detection of the afterglow
  30. GRB 050315: Variability Analysis of Swift BAT Time History
  31. GRB050319: BR optical photometry
  32. GRB 050318: SWIFT-UVOT refined analysis
  33. GRB 050319: Swift-BAT refined analysis
  34. GRB050319,optical observation
  35. Swift Detection of GRB 050319
  36. GRB 050319: Detection of Possible Optical Counterpart
  37. GRB 050318: Swift/UVOT detection of afterglow emission
  38. GRB050318: Swift XRT position
  39. Swift-BAT detection of GRB 050318
  40. GRB050223: analysis of the XMM-Newton observation
  41. GRB 050306: ROTSE-III early limits
  42. GRB 050315: Swift-BAT further refined analysis
  43. GRB050315: Swift-BAT Refined analysis
  44. Non-detection of GRB050315 in ATCA Radio Observations
  45. GRB 050315: Swift XRT Position
  46. GRB 050315: Early Observations with Swift/UVOT
  47. Swift-BAT detection of GRB 050315
  48. GRB050223: No XMM-Newton OM detection of afterglow emission
  49. GRB050309: CONCAM pre-trigger and trigger coincident optical
  50. GRB 050126: Redshift determination
  51. Swift-BAT trigger 107873: No Swift XRT counterpart
  52. GRB 050306: Confirmation of X-ray afterglow
  53. GRB 050309, Early optical limits from RAPTOR
  54. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  55. GRB 050309 : Lulin R-band observation
  56. Swift 107873: P60 Optical Observations
  57. GRB 050306: CORRECTION to date of observation
  58. GRB 050306: No Swift UVOT Optical Counterpart Detected
  59. GRB 050306: Possible X-ray Afterglow Position from the Swift
  60. Swift trigger 107518: optical observation
  61. GRB 050306,optical observation
  62. GRB 050306: Swift-BAT detection of a long burst
  63. Ongoing activity of SGR 1806-20 after the giant flare
  64. GRB050215B: Late-Time Swift UVOT Observations
  65. PROMPT VRcIc Observations of GRB 050223
  66. GRB 050223: optical observations
  67. GRB050223 XMM-Newton observation
  68. INTEGRAL detection of GRB 050223
  69. GRB050223: No Swift UVOT Detection of Afterglow Emission
  70. GRB050223: ROTSE-III Optical Observations
  71. GRB 050223 Swift/BAT detection of a burst
  72. GRB 050223: Swift XRT Position
  73. GRB050219b: CORRECTION to time of UVOT observations
  74. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  75. GRB 050219b: CORRECTION to refined XRT position
  76. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  77. GRB 050219b: Refined XRT position
  78. GRB 050219b: Swift-BAT detection of a burst
  79. GRB 050219b: CORRECTION: Swift XRT Position
  80. GRB 050219b: Swift XRT Position
  81. GRB 050219a, optical observations
  82. GRB 050219a: Refined XRT position
  83. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  84. GRB 050219: Swift-BAT detection of a burst
  85. GRB050215b: Swift UVOT Detection of Afterglow Emission
  86. GRB 050219: Prompt X-ray position
  87. GRB 050215b: XRT confirmation of IR afterglow candidate
  88. GRB050215b: P60 Optical Observations
  89. GRB 050215b: Swift XRT Source Variability
  90. GRB 050215B: candidate afterglow
  91. GRB 050215b : Lulin follow-up observation
  92. GRB 050215b, BOOTES-2 simultaneous optical observations
  93. GRB 050215B: UKIRT K-band imaging
  94. GRB 050215b: Swift XRT Observations
  95. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  96. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  97. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  98. GRB050215B: ROTSE-III optical observations
  99. GRB050215A: ROTSE-III Optical Observations
  100. short/hard GRB 050202, optical observations

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