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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"

45450 results found.

  1. GRB 050408: steepening of the optical decay
  2. GRB 050408: Optical afterglow confirmed
  3. GRB 050408: opitcal observation
  4. GRB 050408, optical observations
  5. GRB 050408 optical candidate
  6. GRB 050408: Swift XRT Position
  7. GRB 050408: ROTSE-III Optical Limits
  8. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  9. GRB050408: MASTER optical observations
  10. GRB050401: Radio Detection
  11. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  12. GRB 050406: Magellan optical observations
  13. GRB 050406: early Swift XRT analysis results
  14. GRB 050406 BAT refined analysis
  15. GRB 050406: Early observations with Swift-UVOT
  16. GRB 050406: Swift XRT Position
  17. Swift-BAT detection of GRB 050406
  18. Konus-Wind observation of GRB 050401
  19. GRB050401: Radio observation at 610 MHz with GMRT
  20. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  21. GRB 050401: VLT spectroscopic redshift
  22. GRB 050401 Optical Observations
  23. GRB050401: Maidanak optical observation
  24. GRB 050401 BAT refined analysis
  25. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  26. GRB050401: TNG R-band observation
  27. GRB 050402A: IR Analysis
  28. GRB050402: XDSS counterpart
  29. GRB 050402A: IR Observations
  30. GRB 050402: Early observations with Swift-UVOT
  31. Swift Trigger 113225: P60 Observations
  32. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  33. GRB 050401: Optical afterglow confirmed
  34. GRB 050401: Optical afterglow candidate
  35. Swift-BAT detection of GRB 050401
  36. GRB 050401: Prompt XRT position
  37. Retraction of three Swift GRB triggers
  38. GRB050331: No Afterglow Detected
  39. Swift-BAT detection of GRB 050331b
  40. GRB 050331: Swift UVOT Source
  41. Swift-BAT detection of GRB 050331
  42. GRB 050331: Swift XRT Position
  43. Swift Data Publicly Available Starting April 5, 2005
  44. GRB050319: radio observation
  45. Konus-Wind observation of GRB 050326
  46. GRB050326: optical limit
  47. GRB 050326: Early observations with Swift-UVOT
  48. GRB 050326 XMM-Newton observation
  49. GRB 050326 : Planned XMM-Newton observation
  50. GRB 050326: Swift XRT Position
  51. GRB050326: optical limit 33min before GRB
  52. GRB 050326 BAT refined analysis
  53. GRB050326: delayed XRT observation
  54. Swift-BAT detection of a bright GRB 050326
  55. GRB050319, optical observations
  56. GRB050319, color indices
  57. GRB050319: optical observation, March 20-22
  58. GRB050319: RTT150 Optical Observations
  59. Swift-BAT detection of a bright outburst from SGR1806-20
  60. Swift-BAT trigger 112060 is not a real GRB
  61. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  62. GRB 050319: ROTSE-III Refined Analysis
  63. GRB 050318: Swift-BAT refined analysis
  64. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  65. GRB050319: VLA Observations
  66. GRB050319: radio observation
  67. GRB 050319 R band observations
  68. GRB 050319: Swift-UVOT detection of the afterglow
  69. GRB 050315: Variability Analysis of Swift BAT Time History
  70. GRB050319: Radio Observations
  71. GRB 050319: NIR afterglow candidate
  72. GRB 050319:Near IR afterglow
  73. GRB050319: BR optical photometry
  74. GRB 050318: SWIFT-UVOT refined analysis
  75. GRB 050318: Absorption redshift from Magellan
  76. GRB 050319: Optical observation
  77. GRB 050319 : Confirmation of optical afterglow decay
  78. GRB 050319: Swift-BAT refined analysis
  79. GRB050319,optical observation
  80. Swift Detection of GRB 050319
  81. GRB 050319: Detection of Possible Optical Counterpart
  82. GRB 050318: Swift/UVOT detection of afterglow emission
  83. GRB 050318: Magellan optical afterglow identification
  84. GRB050318: Swift XRT position
  85. RXTE Observations of GRB050318
  86. Swift-BAT detection of GRB 050318
  87. GRB 050315, SMARTS optical afterglow decay
  88. GRB050223: analysis of the XMM-Newton observation
  89. GRB050316: MASTER before, simultanious and follow up optical
  90. GRB 050306: ROTSE-III early limits
  91. GRB050316: MASTER optical observations
  92. GRB 050315: Swift-BAT further refined analysis
  93. GRB 050315, SMARTS optical/IR afterglow observations
  94. GRB 050315 I-band observations
  95. GRB050315: Radio afterglow
  96. GRB 050315: Absorption redshift
  97. GRB 050315: Optical afterglow identification
  98. GRB050315: Swift-BAT Refined analysis
  99. Non-detection of GRB050315 in ATCA Radio Observations
  100. GRB 050315: Swift XRT Position

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