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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"

35349 results found.

  1. GRB 050406: early Swift XRT analysis results
  2. GRB 050406 BAT refined analysis
  3. GRB 050406: Early observations with Swift-UVOT
  4. GRB 050406: Swift XRT Position
  5. Swift-BAT detection of GRB 050406
  6. Konus-Wind observation of GRB 050401
  7. GRB050401: Radio observation at 610 MHz with GMRT
  8. GRB 050401: VLT spectroscopic redshift
  9. GRB 050401 Optical Observations
  10. GRB 050401 BAT refined analysis
  11. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  12. GRB050401: TNG R-band observation
  13. GRB 050402A: IR Analysis
  14. GRB 050402A: IR Observations
  15. GRB 050402: Early observations with Swift-UVOT
  16. Swift Trigger 113225: P60 Observations
  17. GRB 050401: Optical afterglow confirmed
  18. GRB 050401: Optical afterglow candidate
  19. Swift-BAT detection of GRB 050401
  20. GRB 050401: Prompt XRT position
  21. Retraction of three Swift GRB triggers
  22. GRB050331: No Afterglow Detected
  23. Swift-BAT detection of GRB 050331b
  24. GRB 050331: Swift UVOT Source
  25. Swift-BAT detection of GRB 050331
  26. GRB 050331: Swift XRT Position
  27. GRB050319: radio observation
  28. Konus-Wind observation of GRB 050326
  29. GRB 050326: Early observations with Swift-UVOT
  30. GRB 050326 XMM-Newton observation
  31. GRB 050326 : Planned XMM-Newton observation
  32. GRB 050326: Swift XRT Position
  33. GRB050326: optical limit 33min before GRB
  34. GRB 050326 BAT refined analysis
  35. GRB050326: delayed XRT observation
  36. Swift-BAT detection of a bright GRB 050326
  37. GRB050319, color indices
  38. GRB050319: RTT150 Optical Observations
  39. Swift-BAT trigger 112060 is not a real GRB
  40. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  41. GRB 050319: ROTSE-III Refined Analysis
  42. GRB 050318: Swift-BAT refined analysis
  43. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  44. GRB050319: VLA Observations
  45. GRB 050319 R band observations
  46. GRB 050319: Swift-UVOT detection of the afterglow
  47. GRB 050315: Variability Analysis of Swift BAT Time History
  48. GRB050319: Radio Observations
  49. GRB 050319: NIR afterglow candidate
  50. GRB 050319:Near IR afterglow
  51. GRB 050318: SWIFT-UVOT refined analysis
  52. GRB 050318: Absorption redshift from Magellan
  53. GRB 050319: Optical observation
  54. GRB 050319 : Confirmation of optical afterglow decay
  55. GRB 050319: Swift-BAT refined analysis
  56. GRB050319,optical observation
  57. Swift Detection of GRB 050319
  58. GRB 050319: Detection of Possible Optical Counterpart
  59. GRB 050318: Swift/UVOT detection of afterglow emission
  60. GRB 050318: Magellan optical afterglow identification
  61. GRB050318: Swift XRT position
  62. RXTE Observations of GRB050318
  63. Swift-BAT detection of GRB 050318
  64. GRB 050315, SMARTS optical afterglow decay
  65. GRB050316: MASTER before, simultanious and follow up optical
  66. GRB 050306: ROTSE-III early limits
  67. GRB050316: MASTER optical observations
  68. GRB 050315: Swift-BAT further refined analysis
  69. GRB 050315, SMARTS optical/IR afterglow observations
  70. GRB 050315 I-band observations
  71. GRB050315: Radio afterglow
  72. GRB 050315: Absorption redshift
  73. GRB 050315: Optical afterglow identification
  74. GRB050315: Swift-BAT Refined analysis
  75. Non-detection of GRB050315 in ATCA Radio Observations
  76. GRB 050315: Swift XRT Position
  77. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  78. GRB 050315: Early Observations with Swift/UVOT
  79. Swift-BAT detection of GRB 050315
  80. GRB 050306: Radio Observations
  81. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  82. GRB050309: CONCAM pre-trigger and trigger coincident optical
  83. GRB 050306: optical afterglow
  84. GRB 050126: Redshift determination
  85. Swift-BAT trigger 107873: No Swift XRT counterpart
  86. GRB 050306: Confirmation of X-ray afterglow
  87. GRB 050309, Early optical limits from RAPTOR
  88. GRB 050306: further TAROT optical data
  89. GRB050309: Early optical limit from P60
  90. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  91. GRB 050309 : Lulin R-band observation
  92. Swift 107873: P60 Optical Observations
  93. GRB 050306: CORRECTION to date of observation
  94. GRB 050306: R-band observations
  95. GRB 050306: No Swift UVOT Optical Counterpart Detected
  96. GRB 050306: REM optical-infrared observations
  97. GRB 050306: Possible X-ray Afterglow Position from the Swift
  98. Swift trigger 107518: optical observation
  99. GRB 050306: TAROT optical observations
  100. GRB 050306,optical observation

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