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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"

28093 results found.

  1. GRB 051022 (=H3950): SXC Flight Localization is Valid
  2. GRB051021: Swift/UVOT Upper Limits
  3. GRB 051021B: Refined analysis of the Swift-BAT burst
  4. GRB 051022: SSO40 Optical Observations
  5. GRB051022,optical observation
  6. GRB 051021,optical observation
  7. GRB 051021B: Swift detection of a burst
  8. GRB 051021 : optical afterglow observation at Lulin
  9. GRB 051021: Optical observations and candidate afterglow
  10. GRB051021.63
  11. GRB051021.6: MASTER optical observation
  12. GRB051021: A GRB Localized by HETE
  13. Swift-BAT triggered on a posible CR Shower or possible GRB
  14. GRB 051016b: Optical limit
  15. Afterglow candidate of GRB 051016B observed at Lulin
  16. GRB 051016A: Swift/UVOT upper limits
  17. GRB 051016B: refined analysis of the Swift/XRT data
  18. GRB 051016B: Swift/UVOT detection
  19. GRB 051016B,optical observation
  20. GRB 051016B : Optical follow-up at Lulin
  21. GRB 051016B: Refined analysis of the Swift-BAT burst
  22. GRB 051016B: Swift detection of a soft burst
  23. GRB 051016: Swift-BAT refined analysis
  24. GRB051016 XMM-Newton observation
  25. GRB051016: Swift XRT refined analysis.
  26. GRB 051016: PROMPT Observations
  27. GRB051016: Swift detection of a burst
  28. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  29. GRB 051012: Swift-BAT detection of burst yesterday
  30. Swift-BAT Trigger 159578 is a possible burst
  31. GRB 051006: Swift/UVOT Upper Limits
  32. GRB051008: optical candidate
  33. GRB 051008 - a low redshift low-luminosity burst?
  34. GRB051011: bright nebulae near error box
  35. GRB051011: MASTER optical observation
  36. GRB051008: Final refined analysis of the Swift-BAT burst
  37. GRB051008: Radio Observation
  38. GRB 051008, optical observations
  39. GRB 051008: early Swift XRT analysis
  40. GRB 051008: Swift UVOT Candidate
  41. GRB 051006: P60 Observations
  42. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  43. GRB 051006: optical observations at Sierra Nevada
  44. GRB051006: Refined analysis of the Swift-BAT burst
  45. GRB051006: Swift detection of a burst
  46. GRB 050906, summary of radio observations
  47. GRB051001: Swift UVOT Upper Limits
  48. GRB 050925: Second Epoch WSRT Radio Observations
  49. GRB 051001: I-band limit
  50. GRB 051001: AAT infra-red observations
  51. GRB 051001: Swift-BAT refined analysis
  52. GRB 051001: Swift Detection of a Burst
  53. GRB 050820A: NIR photometry at the TNG
  54. GRB050925: Swift/XRT limits
  55. GRB/SGR 050925: IR Observations
  56. GRB 050922C: break in the lightcurve
  57. GRB050925: Swift UVOT upper limits
  58. Refined analysis of the Swift-BAT soft short burst
  59. GRB050925: Faulkes Telescope North R-band limit
  60. GRB050925: Swift-BAT detection of a short burst
  61. GRB050922C: TNG spectroscopic observations
  62. GRB050922B: refined XRT analysis
  63. GRB050922B: Swift UVOT early upper limits.
  64. GRB050922C: Optical Observations
  65. GRB 050922C: Swift XRT refined analysis
  66. HETE Fregate observations of GRB 050922C
  67. GRB 050922C: Swift-BAT refined analysis
  68. GRB 050922B: Swift-BAT refined analysis
  69. GRB 050922C: optical obserations
  70. GRB 050922C: NOT optical observations
  71. GRB 050922C: Swift detection of a bright burst
  72. GRB 050922B: ROTSE-III Optical Limits
  73. GRB 050922B,optical observation
  74. GRB050922B: Swift-BAT detection of a weak long burst
  75. GRB050820B: analysis of the XMM-Newton observation
  76. GRB050916: Swift/UVOT Upper Limits
  77. GRB 050916: Swift-BAT refined analysis
  78. Swift-BAT trigger 155764 is not a GRB
  79. Swift-BAT trigger 155764 is probably not a GRB
  80. Swift trigger 155764: bad XRT centroid
  81. Swift-BAT trigger 155535 is definitely not a GRB
  82. GRB050916 : Swift-XRT refined analysis
  83. GRB 050915B: Swift-BAT refined analysis
  84. GRB 050915B: Swift/UVOT Upper Limits
  85. GRB 050915a: IR Transient
  86. GRB 050915b, SMARTS optical/IR observations
  87. GRB050915B: Swift-BAT detection of a long bright burst
  88. GRB050915: Swift/UVOT upper limits
  89. GRB 050915: IR Observations
  90. GRB 050915: Swift XRT refined analysis
  91. GRB 050915: Swift-BAT refined analysis
  92. GRB 050915: Swift detection of a GRB
  93. GRB050911: Upper limit on X-ray afterglow
  94. Swift-BAT trigger 155072 ground analysis
  95. Swift-BAT trigger 155072 is probably not a GRB
  96. GRB 050908: DEIMOS spectrum and further analysis
  97. GRB 050911, optical content of Swift/XRT error box
  98. GRB 050911: Swift-BAT refined analysis
  99. GRB 050911: z~0.16 cluster in the field
  100. GRB050911: Swift-BAT detection of a long burst

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