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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"

45444 results found.

  1. GRB 050408: Swift XRT Position
  2. GRB 050408: ROTSE-III Optical Limits
  3. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  4. GRB050408: MASTER optical observations
  5. GRB050401: Radio Detection
  6. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  7. GRB 050406: Magellan optical observations
  8. GRB 050406: early Swift XRT analysis results
  9. GRB 050406 BAT refined analysis
  10. GRB 050406: Early observations with Swift-UVOT
  11. GRB 050406: Swift XRT Position
  12. Swift-BAT detection of GRB 050406
  13. Konus-Wind observation of GRB 050401
  14. GRB050401: Radio observation at 610 MHz with GMRT
  15. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  16. GRB 050401: VLT spectroscopic redshift
  17. GRB 050401 Optical Observations
  18. GRB050401: Maidanak optical observation
  19. GRB 050401 BAT refined analysis
  20. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  21. GRB050401: TNG R-band observation
  22. GRB 050402A: IR Analysis
  23. GRB050402: XDSS counterpart
  24. GRB 050402A: IR Observations
  25. GRB 050402: Early observations with Swift-UVOT
  26. Swift Trigger 113225: P60 Observations
  27. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  28. GRB 050401: Optical afterglow confirmed
  29. GRB 050401: Optical afterglow candidate
  30. Swift-BAT detection of GRB 050401
  31. GRB 050401: Prompt XRT position
  32. Retraction of three Swift GRB triggers
  33. GRB050331: No Afterglow Detected
  34. Swift-BAT detection of GRB 050331b
  35. GRB 050331: Swift UVOT Source
  36. Swift-BAT detection of GRB 050331
  37. GRB 050331: Swift XRT Position
  38. Swift Data Publicly Available Starting April 5, 2005
  39. GRB050319: radio observation
  40. Konus-Wind observation of GRB 050326
  41. GRB050326: optical limit
  42. GRB 050326: Early observations with Swift-UVOT
  43. GRB 050326 XMM-Newton observation
  44. GRB 050326 : Planned XMM-Newton observation
  45. GRB 050326: Swift XRT Position
  46. GRB050326: optical limit 33min before GRB
  47. GRB 050326 BAT refined analysis
  48. GRB050326: delayed XRT observation
  49. Swift-BAT detection of a bright GRB 050326
  50. GRB050319, optical observations
  51. GRB050319, color indices
  52. GRB050319: optical observation, March 20-22
  53. Swift-BAT detection of a bright outburst from SGR1806-20
  54. Swift-BAT trigger 112060 is not a real GRB
  55. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  56. GRB 050319: ROTSE-III Refined Analysis
  57. GRB 050318: Swift-BAT refined analysis
  58. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  59. GRB050319: VLA Observations
  60. GRB050319: radio observation
  61. GRB 050319 R band observations
  62. GRB 050319: Swift-UVOT detection of the afterglow
  63. GRB 050315: Variability Analysis of Swift BAT Time History
  64. GRB050319: Radio Observations
  65. GRB 050319: NIR afterglow candidate
  66. GRB 050319:Near IR afterglow
  67. GRB050319: BR optical photometry
  68. GRB 050318: SWIFT-UVOT refined analysis
  69. GRB 050318: Absorption redshift from Magellan
  70. GRB 050319: Optical observation
  71. GRB 050319 : Confirmation of optical afterglow decay
  72. GRB 050319: Swift-BAT refined analysis
  73. GRB050319,optical observation
  74. Swift Detection of GRB 050319
  75. GRB 050319: Detection of Possible Optical Counterpart
  76. GRB 050318: Swift/UVOT detection of afterglow emission
  77. GRB 050318: Magellan optical afterglow identification
  78. GRB050318: Swift XRT position
  79. RXTE Observations of GRB050318
  80. Swift-BAT detection of GRB 050318
  81. GRB 050315, SMARTS optical afterglow decay
  82. GRB050223: analysis of the XMM-Newton observation
  83. GRB050316: MASTER before, simultanious and follow up optical
  84. GRB 050306: ROTSE-III early limits
  85. GRB050316: MASTER optical observations
  86. GRB 050315: Swift-BAT further refined analysis
  87. GRB 050315, SMARTS optical/IR afterglow observations
  88. GRB 050315 I-band observations
  89. GRB050315: Radio afterglow
  90. GRB 050315: Absorption redshift
  91. GRB 050315: Optical afterglow identification
  92. GRB050315: Swift-BAT Refined analysis
  93. Non-detection of GRB050315 in ATCA Radio Observations
  94. GRB 050315: Swift XRT Position
  95. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  96. GRB 050315: Early Observations with Swift/UVOT
  97. Swift-BAT detection of GRB 050315
  98. GRB050223: No XMM-Newton OM detection of afterglow emission
  99. GRB 050306: Radio Observations
  100. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m

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