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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"

35947 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. GRB 050401: VLT spectroscopic redshift
  21. GRB 050401 Optical Observations
  22. GRB 050401 BAT refined analysis
  23. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  24. GRB050401: TNG R-band observation
  25. GRB 050402A: IR Analysis
  26. GRB 050402A: IR Observations
  27. GRB 050402: Early observations with Swift-UVOT
  28. Swift Trigger 113225: P60 Observations
  29. GRB 050401: Optical afterglow confirmed
  30. GRB 050401: Optical afterglow candidate
  31. Swift-BAT detection of GRB 050401
  32. GRB 050401: Prompt XRT position
  33. Retraction of three Swift GRB triggers
  34. GRB050331: No Afterglow Detected
  35. Swift-BAT detection of GRB 050331b
  36. GRB 050331: Swift UVOT Source
  37. Swift-BAT detection of GRB 050331
  38. GRB 050331: Swift XRT Position
  39. GRB050319: radio observation
  40. Konus-Wind observation of GRB 050326
  41. GRB 050326: Early observations with Swift-UVOT
  42. GRB 050326 XMM-Newton observation
  43. GRB 050326 : Planned XMM-Newton observation
  44. GRB 050326: Swift XRT Position
  45. GRB050326: optical limit 33min before GRB
  46. GRB 050326 BAT refined analysis
  47. GRB050326: delayed XRT observation
  48. Swift-BAT detection of a bright GRB 050326
  49. GRB050319, color indices
  50. GRB050319: RTT150 Optical Observations
  51. Swift-BAT trigger 112060 is not a real GRB
  52. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  53. GRB 050319: ROTSE-III Refined Analysis
  54. GRB 050318: Swift-BAT refined analysis
  55. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  56. GRB050319: VLA Observations
  57. GRB 050319 R band observations
  58. GRB 050319: Swift-UVOT detection of the afterglow
  59. GRB 050315: Variability Analysis of Swift BAT Time History
  60. GRB050319: Radio Observations
  61. GRB 050319: NIR afterglow candidate
  62. GRB 050319:Near IR afterglow
  63. GRB 050318: SWIFT-UVOT refined analysis
  64. GRB 050318: Absorption redshift from Magellan
  65. GRB 050319: Optical observation
  66. GRB 050319 : Confirmation of optical afterglow decay
  67. GRB 050319: Swift-BAT refined analysis
  68. GRB050319,optical observation
  69. Swift Detection of GRB 050319
  70. GRB 050319: Detection of Possible Optical Counterpart
  71. GRB 050318: Swift/UVOT detection of afterglow emission
  72. GRB 050318: Magellan optical afterglow identification
  73. GRB050318: Swift XRT position
  74. RXTE Observations of GRB050318
  75. Swift-BAT detection of GRB 050318
  76. GRB 050315, SMARTS optical afterglow decay
  77. GRB050316: MASTER before, simultanious and follow up optical
  78. GRB 050306: ROTSE-III early limits
  79. GRB050316: MASTER optical observations
  80. GRB 050315: Swift-BAT further refined analysis
  81. GRB 050315, SMARTS optical/IR afterglow observations
  82. GRB 050315 I-band observations
  83. GRB050315: Radio afterglow
  84. GRB 050315: Absorption redshift
  85. GRB 050315: Optical afterglow identification
  86. GRB050315: Swift-BAT Refined analysis
  87. Non-detection of GRB050315 in ATCA Radio Observations
  88. GRB 050315: Swift XRT Position
  89. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  90. GRB 050315: Early Observations with Swift/UVOT
  91. Swift-BAT detection of GRB 050315
  92. GRB 050306: Radio Observations
  93. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  94. GRB050309: CONCAM pre-trigger and trigger coincident optical
  95. GRB 050306: optical afterglow
  96. GRB 050126: Redshift determination
  97. Swift-BAT trigger 107873: No Swift XRT counterpart
  98. GRB 050306: Confirmation of X-ray afterglow
  99. GRB 050309, Early optical limits from RAPTOR
  100. GRB 050306: further TAROT optical data

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