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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"

19359 results found.

  1. GRB050326: optical limit 33min before GRB
  2. GRB 050326 BAT refined analysis
  3. GRB050326: delayed XRT observation
  4. Swift-BAT detection of a bright GRB 050326
  5. GRB050319, optical observations
  6. GRB050319, color indices
  7. GRB050319: RTT150 Optical Observations
  8. Swift-BAT detection of a bright outburst from SGR1806-20
  9. Swift-BAT trigger 112060 is not a real GRB
  10. GRB 050319: ROTSE-III Refined Analysis
  11. GRB 050318: Swift-BAT refined analysis
  12. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  13. GRB 050319 R band observations
  14. GRB 050319: Swift-UVOT detection of the afterglow
  15. GRB 050315: Variability Analysis of Swift BAT Time History
  16. GRB050319: BR optical photometry
  17. GRB 050318: SWIFT-UVOT refined analysis
  18. GRB 050319: Swift-BAT refined analysis
  19. GRB050319,optical observation
  20. Swift Detection of GRB 050319
  21. GRB 050319: Detection of Possible Optical Counterpart
  22. GRB 050318: Swift/UVOT detection of afterglow emission
  23. GRB050318: Swift XRT position
  24. Swift-BAT detection of GRB 050318
  25. GRB050223: analysis of the XMM-Newton observation
  26. GRB 050306: ROTSE-III early limits
  27. GRB 050315: Swift-BAT further refined analysis
  28. GRB050315: Swift-BAT Refined analysis
  29. Non-detection of GRB050315 in ATCA Radio Observations
  30. GRB 050315: Swift XRT Position
  31. GRB 050315: Early Observations with Swift/UVOT
  32. Swift-BAT detection of GRB 050315
  33. GRB050223: No XMM-Newton OM detection of afterglow emission
  34. GRB050309: CONCAM pre-trigger and trigger coincident optical
  35. GRB 050126: Redshift determination
  36. Swift-BAT trigger 107873: No Swift XRT counterpart
  37. GRB 050306: Confirmation of X-ray afterglow
  38. GRB 050309, Early optical limits from RAPTOR
  39. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  40. GRB 050309 : Lulin R-band observation
  41. Swift 107873: P60 Optical Observations
  42. GRB 050306: CORRECTION to date of observation
  43. GRB 050306: No Swift UVOT Optical Counterpart Detected
  44. GRB 050306: Possible X-ray Afterglow Position from the Swift
  45. Swift trigger 107518: optical observation
  46. GRB 050306,optical observation
  47. GRB 050306: Swift-BAT detection of a long burst
  48. GRB050215B: Late-Time Swift UVOT Observations
  49. PROMPT VRcIc Observations of GRB 050223
  50. GRB 050223: optical observations
  51. GRB050223 XMM-Newton observation
  52. INTEGRAL detection of GRB 050223
  53. GRB050223: No Swift UVOT Detection of Afterglow Emission
  54. GRB050223: ROTSE-III Optical Observations
  55. GRB 050223 Swift/BAT detection of a burst
  56. GRB 050223: Swift XRT Position
  57. GRB050219b: CORRECTION to time of UVOT observations
  58. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  59. GRB 050219b: CORRECTION to refined XRT position
  60. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  61. GRB 050219b: Refined XRT position
  62. GRB 050219b: Swift-BAT detection of a burst
  63. GRB 050219b: CORRECTION: Swift XRT Position
  64. GRB 050219b: Swift XRT Position
  65. GRB 050219a, optical observations
  66. GRB 050219a: Refined XRT position
  67. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  68. GRB 050219: Swift-BAT detection of a burst
  69. GRB050215b: Swift UVOT Detection of Afterglow Emission
  70. GRB 050219: Prompt X-ray position
  71. GRB 050215b: XRT confirmation of IR afterglow candidate
  72. GRB050215b: P60 Optical Observations
  73. GRB 050215b: Swift XRT Source Variability
  74. GRB 050215B: candidate afterglow
  75. GRB 050215b : Lulin follow-up observation
  76. GRB 050215b, BOOTES-2 simultaneous optical observations
  77. GRB 050215B: UKIRT K-band imaging
  78. GRB 050215b: Swift XRT Observations
  79. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  80. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  81. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  82. GRB050215B: ROTSE-III optical observations
  83. GRB050215A: ROTSE-III Optical Observations
  84. short/hard GRB 050202, optical observations
  85. GRB 050128: Radio observations
  86. Further analysis of the short Swift-BAT GRB 050202
  87. GRB 050202: Second epoch radio observations
  88. GRB050202: Radio Observations
  89. GRB 050202: Short burst detected by Swift-BAT
  90. SGR1806-20: Swift-BAT detection of a large normal burst
  91. GRB050128: Faulkes Telescope South observations
  92. GRB050128,optical observations
  93. GRB050126: Updated Swift XRT Position
  94. GRB 050126: Radio Observations
  95. GRB050128 Swift-BAT observations
  96. GRB 050128: Swift XRT prompt afterglow position
  97. GRB 050124: K-band afterglow observations
  98. GRB050126: MASTER optical limit for KECK OT
  99. GRB050126: Burst Parameters Measured by BAT
  100. GRB050126: MASTER optical observations

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