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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"

36137 results found.

  1. Swift-BAT detection of GRB 050406
  2. Konus-Wind observation of GRB 050401
  3. GRB050401: Radio observation at 610 MHz with GMRT
  4. GRB 050401: VLT spectroscopic redshift
  5. GRB 050401 Optical Observations
  6. GRB 050401 BAT refined analysis
  7. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  8. GRB050401: TNG R-band observation
  9. GRB 050402A: IR Analysis
  10. GRB 050402A: IR Observations
  11. GRB 050402: Early observations with Swift-UVOT
  12. Swift Trigger 113225: P60 Observations
  13. GRB 050401: Optical afterglow confirmed
  14. GRB 050401: Optical afterglow candidate
  15. Swift-BAT detection of GRB 050401
  16. GRB 050401: Prompt XRT position
  17. Retraction of three Swift GRB triggers
  18. GRB050331: No Afterglow Detected
  19. Swift-BAT detection of GRB 050331b
  20. GRB 050331: Swift UVOT Source
  21. Swift-BAT detection of GRB 050331
  22. GRB 050331: Swift XRT Position
  23. GRB050319: radio observation
  24. Konus-Wind observation of GRB 050326
  25. GRB 050326: Early observations with Swift-UVOT
  26. GRB 050326 XMM-Newton observation
  27. GRB 050326 : Planned XMM-Newton observation
  28. GRB 050326: Swift XRT Position
  29. GRB050326: optical limit 33min before GRB
  30. GRB 050326 BAT refined analysis
  31. GRB050326: delayed XRT observation
  32. Swift-BAT detection of a bright GRB 050326
  33. GRB050319, color indices
  34. GRB050319: RTT150 Optical Observations
  35. Swift-BAT trigger 112060 is not a real GRB
  36. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  37. GRB 050319: ROTSE-III Refined Analysis
  38. GRB 050318: Swift-BAT refined analysis
  39. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  40. GRB050319: VLA Observations
  41. GRB 050319 R band observations
  42. GRB 050319: Swift-UVOT detection of the afterglow
  43. GRB 050315: Variability Analysis of Swift BAT Time History
  44. GRB050319: Radio Observations
  45. GRB 050319: NIR afterglow candidate
  46. GRB 050319:Near IR afterglow
  47. GRB 050318: SWIFT-UVOT refined analysis
  48. GRB 050318: Absorption redshift from Magellan
  49. GRB 050319: Optical observation
  50. GRB 050319 : Confirmation of optical afterglow decay
  51. GRB 050319: Swift-BAT refined analysis
  52. GRB050319,optical observation
  53. Swift Detection of GRB 050319
  54. GRB 050319: Detection of Possible Optical Counterpart
  55. GRB 050318: Swift/UVOT detection of afterglow emission
  56. GRB 050318: Magellan optical afterglow identification
  57. GRB050318: Swift XRT position
  58. RXTE Observations of GRB050318
  59. Swift-BAT detection of GRB 050318
  60. GRB 050315, SMARTS optical afterglow decay
  61. GRB050316: MASTER before, simultanious and follow up optical
  62. GRB 050306: ROTSE-III early limits
  63. GRB050316: MASTER optical observations
  64. GRB 050315: Swift-BAT further refined analysis
  65. GRB 050315, SMARTS optical/IR afterglow observations
  66. GRB 050315 I-band observations
  67. GRB050315: Radio afterglow
  68. GRB 050315: Absorption redshift
  69. GRB 050315: Optical afterglow identification
  70. GRB050315: Swift-BAT Refined analysis
  71. Non-detection of GRB050315 in ATCA Radio Observations
  72. GRB 050315: Swift XRT Position
  73. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  74. GRB 050315: Early Observations with Swift/UVOT
  75. Swift-BAT detection of GRB 050315
  76. GRB 050306: Radio Observations
  77. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  78. GRB050309: CONCAM pre-trigger and trigger coincident optical
  79. GRB 050306: optical afterglow
  80. GRB 050126: Redshift determination
  81. Swift-BAT trigger 107873: No Swift XRT counterpart
  82. GRB 050306: Confirmation of X-ray afterglow
  83. GRB 050309, Early optical limits from RAPTOR
  84. GRB 050306: further TAROT optical data
  85. GRB050309: Early optical limit from P60
  86. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  87. GRB 050309 : Lulin R-band observation
  88. Swift 107873: P60 Optical Observations
  89. GRB 050306: CORRECTION to date of observation
  90. GRB 050306: R-band observations
  91. GRB 050306: No Swift UVOT Optical Counterpart Detected
  92. GRB 050306: REM optical-infrared observations
  93. GRB 050306: Possible X-ray Afterglow Position from the Swift
  94. Swift trigger 107518: optical observation
  95. GRB 050306: TAROT optical observations
  96. GRB 050306,optical observation
  97. GRB 050306: Swift-BAT detection of a long burst
  98. GRB 050126: Confirmation of the NIR afterglow candidate
  99. PROMPT VRcIc Observations of GRB 050223
  100. XRF/GRB 050215B: Radio Observations

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