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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"

36130 results found.

  1. GRB050401: TNG R-band observation
  2. GRB 050402A: IR Analysis
  3. GRB 050402A: IR Observations
  4. GRB 050402: Early observations with Swift-UVOT
  5. Swift Trigger 113225: P60 Observations
  6. GRB 050401: Optical afterglow confirmed
  7. GRB 050401: Optical afterglow candidate
  8. Swift-BAT detection of GRB 050401
  9. GRB 050401: Prompt XRT position
  10. Retraction of three Swift GRB triggers
  11. GRB050331: No Afterglow Detected
  12. Swift-BAT detection of GRB 050331b
  13. GRB 050331: Swift UVOT Source
  14. Swift-BAT detection of GRB 050331
  15. GRB 050331: Swift XRT Position
  16. GRB050319: radio observation
  17. Konus-Wind observation of GRB 050326
  18. GRB 050326: Early observations with Swift-UVOT
  19. GRB 050326 XMM-Newton observation
  20. GRB 050326 : Planned XMM-Newton observation
  21. GRB 050326: Swift XRT Position
  22. GRB050326: optical limit 33min before GRB
  23. GRB 050326 BAT refined analysis
  24. GRB050326: delayed XRT observation
  25. Swift-BAT detection of a bright GRB 050326
  26. GRB050319, color indices
  27. GRB050319: RTT150 Optical Observations
  28. Swift-BAT trigger 112060 is not a real GRB
  29. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  30. GRB 050319: ROTSE-III Refined Analysis
  31. GRB 050318: Swift-BAT refined analysis
  32. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  33. GRB050319: VLA Observations
  34. GRB 050319 R band observations
  35. GRB 050319: Swift-UVOT detection of the afterglow
  36. GRB 050315: Variability Analysis of Swift BAT Time History
  37. GRB050319: Radio Observations
  38. GRB 050319: NIR afterglow candidate
  39. GRB 050319:Near IR afterglow
  40. GRB 050318: SWIFT-UVOT refined analysis
  41. GRB 050318: Absorption redshift from Magellan
  42. GRB 050319: Optical observation
  43. GRB 050319 : Confirmation of optical afterglow decay
  44. GRB 050319: Swift-BAT refined analysis
  45. GRB050319,optical observation
  46. Swift Detection of GRB 050319
  47. GRB 050319: Detection of Possible Optical Counterpart
  48. GRB 050318: Swift/UVOT detection of afterglow emission
  49. GRB 050318: Magellan optical afterglow identification
  50. GRB050318: Swift XRT position
  51. RXTE Observations of GRB050318
  52. Swift-BAT detection of GRB 050318
  53. GRB 050315, SMARTS optical afterglow decay
  54. GRB050316: MASTER before, simultanious and follow up optical
  55. GRB 050306: ROTSE-III early limits
  56. GRB050316: MASTER optical observations
  57. GRB 050315: Swift-BAT further refined analysis
  58. GRB 050315, SMARTS optical/IR afterglow observations
  59. GRB 050315 I-band observations
  60. GRB050315: Radio afterglow
  61. GRB 050315: Absorption redshift
  62. GRB 050315: Optical afterglow identification
  63. GRB050315: Swift-BAT Refined analysis
  64. Non-detection of GRB050315 in ATCA Radio Observations
  65. GRB 050315: Swift XRT Position
  66. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  67. GRB 050315: Early Observations with Swift/UVOT
  68. Swift-BAT detection of GRB 050315
  69. GRB 050306: Radio Observations
  70. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  71. GRB050309: CONCAM pre-trigger and trigger coincident optical
  72. GRB 050306: optical afterglow
  73. GRB 050126: Redshift determination
  74. Swift-BAT trigger 107873: No Swift XRT counterpart
  75. GRB 050306: Confirmation of X-ray afterglow
  76. GRB 050309, Early optical limits from RAPTOR
  77. GRB 050306: further TAROT optical data
  78. GRB050309: Early optical limit from P60
  79. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  80. GRB 050309 : Lulin R-band observation
  81. Swift 107873: P60 Optical Observations
  82. GRB 050306: CORRECTION to date of observation
  83. GRB 050306: R-band observations
  84. GRB 050306: No Swift UVOT Optical Counterpart Detected
  85. GRB 050306: REM optical-infrared observations
  86. GRB 050306: Possible X-ray Afterglow Position from the Swift
  87. Swift trigger 107518: optical observation
  88. GRB 050306: TAROT optical observations
  89. GRB 050306,optical observation
  90. GRB 050306: Swift-BAT detection of a long burst
  91. GRB 050126: Confirmation of the NIR afterglow candidate
  92. PROMPT VRcIc Observations of GRB 050223
  93. XRF/GRB 050215B: Radio Observations
  94. XMM-Newton Images of GRB 050223
  95. GRB 050219b: candidate NIR afterglow
  96. IBAS GRB Alert #2321
  97. GRB 050223: optical observations
  98. INTEGRAL detection of GRB 050223
  99. GRB 050223 : Planned XMM-Newton observation
  100. GRB050223: ROTSE-III Optical Observations

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