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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"

36155 results found.

  1. GRB 050408: Magellan astrometry and photometry
  2. GRB 050408: First Optical observations with TFOSC at the RTT150
  3. GRB 050408: steepening of the optical decay
  4. GRB 050408: Optical afterglow confirmed
  5. GRB 050408: opitcal observation
  6. GRB 050408, optical observations
  7. GRB 050408 optical candidate
  8. GRB 050408: Swift XRT Position
  9. GRB 050408: ROTSE-III Optical Limits
  10. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  11. GRB050408: MASTER optical observations
  12. GRB050401: Radio Detection
  13. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  14. GRB 050406: Magellan optical observations
  15. GRB 050406: early Swift XRT analysis results
  16. GRB 050406 BAT refined analysis
  17. GRB 050406: Early observations with Swift-UVOT
  18. GRB 050406: Swift XRT Position
  19. Swift-BAT detection of GRB 050406
  20. Konus-Wind observation of GRB 050401
  21. GRB050401: Radio observation at 610 MHz with GMRT
  22. GRB 050401: VLT spectroscopic redshift
  23. GRB 050401 Optical Observations
  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. GRB 050402A: IR Observations
  29. GRB 050402: Early observations with Swift-UVOT
  30. Swift Trigger 113225: P60 Observations
  31. GRB 050401: Optical afterglow confirmed
  32. GRB 050401: Optical afterglow candidate
  33. Swift-BAT detection of GRB 050401
  34. GRB 050401: Prompt XRT position
  35. Retraction of three Swift GRB triggers
  36. GRB050331: No Afterglow Detected
  37. Swift-BAT detection of GRB 050331b
  38. GRB 050331: Swift UVOT Source
  39. Swift-BAT detection of GRB 050331
  40. GRB 050331: Swift XRT Position
  41. GRB050319: radio observation
  42. Konus-Wind observation of GRB 050326
  43. GRB 050326: Early observations with Swift-UVOT
  44. GRB 050326 XMM-Newton observation
  45. GRB 050326 : Planned XMM-Newton observation
  46. GRB 050326: Swift XRT Position
  47. GRB050326: optical limit 33min before GRB
  48. GRB 050326 BAT refined analysis
  49. GRB050326: delayed XRT observation
  50. Swift-BAT detection of a bright GRB 050326
  51. GRB050319, color indices
  52. GRB050319: RTT150 Optical Observations
  53. Swift-BAT trigger 112060 is not a real GRB
  54. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  55. GRB 050319: ROTSE-III Refined Analysis
  56. GRB 050318: Swift-BAT refined analysis
  57. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  58. GRB050319: VLA Observations
  59. GRB 050319 R band observations
  60. GRB 050319: Swift-UVOT detection of the afterglow
  61. GRB 050315: Variability Analysis of Swift BAT Time History
  62. GRB050319: Radio Observations
  63. GRB 050319: NIR afterglow candidate
  64. GRB 050319:Near IR afterglow
  65. GRB 050318: SWIFT-UVOT refined analysis
  66. GRB 050318: Absorption redshift from Magellan
  67. GRB 050319: Optical observation
  68. GRB 050319 : Confirmation of optical afterglow decay
  69. GRB 050319: Swift-BAT refined analysis
  70. GRB050319,optical observation
  71. Swift Detection of GRB 050319
  72. GRB 050319: Detection of Possible Optical Counterpart
  73. GRB 050318: Swift/UVOT detection of afterglow emission
  74. GRB 050318: Magellan optical afterglow identification
  75. GRB050318: Swift XRT position
  76. RXTE Observations of GRB050318
  77. Swift-BAT detection of GRB 050318
  78. GRB 050315, SMARTS optical afterglow decay
  79. GRB050316: MASTER before, simultanious and follow up optical
  80. GRB 050306: ROTSE-III early limits
  81. GRB050316: MASTER optical observations
  82. GRB 050315: Swift-BAT further refined analysis
  83. GRB 050315, SMARTS optical/IR afterglow observations
  84. GRB 050315 I-band observations
  85. GRB050315: Radio afterglow
  86. GRB 050315: Absorption redshift
  87. GRB 050315: Optical afterglow identification
  88. GRB050315: Swift-BAT Refined analysis
  89. Non-detection of GRB050315 in ATCA Radio Observations
  90. GRB 050315: Swift XRT Position
  91. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  92. GRB 050315: Early Observations with Swift/UVOT
  93. Swift-BAT detection of GRB 050315
  94. GRB 050306: Radio Observations
  95. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  96. GRB050309: CONCAM pre-trigger and trigger coincident optical
  97. GRB 050306: optical afterglow
  98. GRB 050126: Redshift determination
  99. Swift-BAT trigger 107873: No Swift XRT counterpart
  100. GRB 050306: Confirmation of X-ray afterglow

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