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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"

25891 results found.

  1. GRB051021b: Magellan IR Imaging
  2. GRB 051021: Correction
  3. GRB 051022, J & K-band observation
  4. GRB 051021, SMARTS optical/IR observations
  5. GRB051022: Swift XRT Position
  6. GRB 051021: P200 Ks Observations
  7. GRB 051021: MDM Upper Limit
  8. GRB051021: Swift/UVOT Upper Limits
  9. GRB 051021B: Refined analysis of the Swift-BAT burst
  10. GRB051021B: Swift XRT Position
  11. GRB 051021: SOAR NIR Observations
  12. GRB 051021B: Swift detection of a burst
  13. GRB051021: Swift XRT analysis
  14. GRB 051021 : optical afterglow observation at Lulin
  15. GRB 051021: Optical observations and candidate afterglow
  16. GRB051021.63
  17. Swift-BAT trigger 160640 is not a real GRB
  18. Swift-BAT trigger 160619 is not a GRB
  19. Swift-BAT triggered on a posible CR Shower or possible GRB
  20. GRB 050502b: Optical limit
  21. GRB 051016b: Optical limit
  22. Afterglow candidate of GRB 051016B observed at Lulin
  23. GRB 051016b: Gemini Near IR Observations
  24. GRB 051016A: Swift/UVOT upper limits
  25. GRB 051016B: refined analysis of the Swift/XRT data
  26. GRB 051016B: Swift/UVOT detection
  27. GRB 051016B : Optical follow-up at Lulin
  28. GRB 051016B: Refined analysis of the Swift-BAT burst
  29. GRB 051016B: Swift detection of a soft burst
  30. GRB 051016: Swift-BAT refined analysis
  31. GRB051016 XMM-Newton observation
  32. GRB051016: Swift XRT refined analysis.
  33. GRB 051016: LCO optical and near-IR imaging
  34. GRB 051016: PROMPT Observations
  35. GRB051016: Swift detection of a burst
  36. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  37. GRB051006: optical observations
  38. GRB 051012: Swift-BAT detection of burst yesterday
  39. Swift trigger 159578 is not a burst
  40. Swift-BAT Trigger 159578 is a possible burst
  41. GRB050805A: Rc optical observations
  42. GRB 051006: Swift/UVOT Upper Limits
  43. GRB051008: optical candidate
  44. GRB 051008 - a low redshift low-luminosity burst?
  45. GRB051008: optical observation
  46. GRB051008: Swift XRT refined analysis
  47. GRB051008 - Swift UVOT upper limits
  48. Konus-Wind observation of GRB 051008
  49. GRB051008: Final refined analysis of the Swift-BAT burst
  50. GRB 051008: R-band upper limit
  51. GRB051008: Refined analysis of the Swift-BAT burst
  52. GRB051008: Radio Observation
  53. GRB 051008: Swift XRT position
  54. GRB 051008, optical observations
  55. GRB 051008: early Swift XRT analysis
  56. GRB 051008: Swift UVOT Candidate
  57. GRB051008: Swift-BAT detection of a bright burst
  58. GRB 051006: P60 Observations
  59. GRB 051006: XRT refined analysis
  60. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  61. GRB 051006: optical observations at Sierra Nevada
  62. GRB051006: Refined analysis of the Swift-BAT burst
  63. GRB 051006: XRT position
  64. GRB051006: Swift detection of a burst
  65. GRB 050906, summary of radio observations
  66. Swift-BAT triggers 158261 and 158262 Retraction
  67. GRB051001: Swift UVOT Upper Limits
  68. GRB 050925: Second Epoch WSRT Radio Observations
  69. GRB 051001: Swift XRT refined analysis
  70. GRB 051001, optical observations at Mt. John
  71. GRB 051001: I-band limit
  72. GRB 051001: AAT infra-red observations
  73. GRB 051001: Swift-BAT refined analysis
  74. GRB 051001: Swift Detection of a Burst
  75. GRB 051001: ROTSE-III Optical Limits
  76. GRB050922B: optical limit
  77. GRB 050922C: further VLT observations
  78. GRB050922C: UVES/VLT high resolution spectroscopy
  79. GRB050925: Swift/XRT limits
  80. GRB/SGR 050925: IR Observations
  81. GRB050922C - Swift UVOT preliminary analysis
  82. GRB 050922C: break in the lightcurve
  83. GRB 050925: WSRT Radio Observations
  84. GRB050925: Swift UVOT upper limits
  85. Refined analysis of the Swift-BAT soft short burst
  86. GRB050925: Faulkes Telescope North R-band limit
  87. GRB050925: Swift-BAT detection of a short burst
  88. GRB 050922B: Correction to BAT refined analysis, longer burst
  89. GRB050922C: TNG spectroscopic observations
  90. GRB050922B: refined XRT analysis
  91. Konus-Wind observation of GRB 050922C
  92. GRB050922B: Swift UVOT early upper limits.
  93. INT 2.5m limit for GRB050922B
  94. GRB 050922B: optical limit
  95. GRB 050922C: Swift XRT refined analysis
  96. HETE Fregate observations of GRB 050922C
  97. GRB 050922C: Swift-BAT refined analysis
  98. GRB 050922B: Swift-BAT refined analysis
  99. GRB050922C: optical observations
  100. GRB 050922C: Absorption redshift from the Nordic Optical Telescope

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