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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"

25299 results found.

  1. GRB 050408: WIDGET simultaneous optical observations
  2. GRB 050408: Properties of the Host Galaxy
  3. GRB050408: Radio Observations
  4. GRB 050408: Swift XRT analysis
  5. GRB 050408: Optical limit at 20 min after the burst
  6. GRB050408: REM NIR and Optical observation
  7. GRB 050408,optical observation
  8. GRB 050408: Mercator Optical Observations
  9. GRB 050408: Optical afterglow confirmed
  10. GRB 050408: opitcal observation
  11. GRB 050408, optical observations
  12. GRB 050408 optical candidate
  13. GRB 050408: Swift XRT Position
  14. GRB050408: MASTER optical observations
  15. GRB050401: Radio Detection
  16. GRB 050406: early Swift XRT analysis results
  17. GRB 050406 BAT refined analysis
  18. GRB 050406: Early observations with Swift-UVOT
  19. Swift-BAT detection of GRB 050406
  20. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  21. GRB 050401: VLT spectroscopic redshift
  22. GRB 050401 BAT refined analysis
  23. GRB050401: TNG R-band observation
  24. GRB 050402: Early observations with Swift-UVOT
  25. Swift Trigger 113225: P60 Observations
  26. GRB 050401: Optical afterglow confirmed
  27. GRB 050401: Prompt XRT position
  28. Retraction of three Swift GRB triggers
  29. GRB050331: No Afterglow Detected
  30. Swift-BAT detection of GRB 050331b
  31. GRB 050331: Swift UVOT Source
  32. Swift-BAT detection of GRB 050331
  33. GRB 050326: Early observations with Swift-UVOT
  34. GRB 050326 XMM-Newton observation
  35. GRB 050326: Swift XRT Position
  36. GRB 050326 BAT refined analysis
  37. GRB050326: delayed XRT observation
  38. GRB050319, color indices
  39. GRB050319: optical observation, March 20-22
  40. GRB050319: RTT150 Optical Observations
  41. Swift-BAT trigger 112060 is not a real GRB
  42. GRB 050318: Swift-BAT refined analysis
  43. GRB050319: VLA Observations
  44. GRB050319: radio observation
  45. GRB 050319: Swift-UVOT detection of the afterglow
  46. GRB 050315: Variability Analysis of Swift BAT Time History
  47. GRB050319: Radio Observations
  48. GRB 050319: NIR afterglow candidate
  49. GRB 050319:Near IR afterglow
  50. GRB 050318: SWIFT-UVOT refined analysis
  51. GRB 050319 : Confirmation of optical afterglow decay
  52. GRB 050319: Swift-BAT refined analysis
  53. GRB050319,optical observation
  54. GRB 050318: Swift/UVOT detection of afterglow emission
  55. RXTE Observations of GRB050318
  56. GRB050223: analysis of the XMM-Newton observation
  57. GRB050316: MASTER before, simultanious and follow up optical
  58. GRB 050306: ROTSE-III early limits
  59. GRB050316: MASTER optical observations
  60. GRB 050315: Swift-BAT further refined analysis
  61. GRB 050315 I-band observations
  62. GRB050315: Radio afterglow
  63. GRB050315: Swift-BAT Refined analysis
  64. Non-detection of GRB050315 in ATCA Radio Observations
  65. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  66. GRB 050315: Early Observations with Swift/UVOT
  67. GRB 050306: Radio Observations
  68. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  69. GRB 050306: optical afterglow
  70. Swift-BAT trigger 107873: No Swift XRT counterpart
  71. GRB 050306: Confirmation of X-ray afterglow
  72. GRB 050306: further TAROT optical data
  73. GRB050309: Early optical limit from P60
  74. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  75. GRB 050309 : Lulin R-band observation
  76. Swift 107873: P60 Optical Observations
  77. GRB 050306: R-band observations
  78. GRB 050306: REM optical-infrared observations
  79. GRB 050306: Possible X-ray Afterglow Position from the Swift
  80. GRB 050306: TAROT optical observations
  81. GRB 050306,optical observation
  82. Ongoing activity of SGR 1806-20 after the giant flare
  83. GRB050215B: Late-Time Swift UVOT Observations
  84. PROMPT VRcIc Observations of GRB 050223
  85. XRF/GRB 050215B: Radio Observations
  86. XMM-Newton Images of GRB 050223
  87. GRB 050219b: candidate NIR afterglow
  88. Confirmed XRF nature for GRB050215b
  89. GRB050223 XMM-Newton observation
  90. INTEGRAL detection of GRB 050223
  91. GRB050223: ROTSE-III Optical Observations
  92. GRB 050223 Swift/BAT detection of a burst
  93. GRB 050223: Swift XRT Position
  94. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  95. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  96. GRB 050219a: Optical observations from LCO
  97. GRB 050219b: Optical and near-IR observations from LCO
  98. GRB 050219b: Swift-BAT detection of a burst
  99. GRB 050219b: CORRECTION: Swift XRT Position
  100. GRB 050219b: Swift XRT Position

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