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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"

27397 results found.

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

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