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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"

28094 results found.

  1. GRB 051021: P200 Ks Observations
  2. GRB 051022 (=H3950): SXC Flight Localization is Valid
  3. GRB051021: Swift/UVOT Upper Limits
  4. GRB 051021B: Refined analysis of the Swift-BAT burst
  5. GRB 051022: SSO40 Optical Observations
  6. GRB051022,optical observation
  7. GRB 051021,optical observation
  8. GRB 051021B: Swift detection of a burst
  9. GRB 051021 : optical afterglow observation at Lulin
  10. GRB 051021: Optical observations and candidate afterglow
  11. GRB051021.63
  12. GRB051021.6: MASTER optical observation
  13. GRB051021: A GRB Localized by HETE
  14. Swift-BAT triggered on a posible CR Shower or possible GRB
  15. GRB 051016b: Optical limit
  16. Afterglow candidate of GRB 051016B observed at Lulin
  17. GRB 051016A: Swift/UVOT upper limits
  18. GRB 051016B: refined analysis of the Swift/XRT data
  19. GRB 051016B: Swift/UVOT detection
  20. GRB 051016B,optical observation
  21. GRB 051016B : Optical follow-up at Lulin
  22. GRB 051016B: Refined analysis of the Swift-BAT burst
  23. GRB 051016B: Swift detection of a soft burst
  24. GRB 051016: Swift-BAT refined analysis
  25. GRB051016 XMM-Newton observation
  26. GRB051016: Swift XRT refined analysis.
  27. GRB 051016: PROMPT Observations
  28. GRB051016: Swift detection of a burst
  29. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  30. GRB 051012: Swift-BAT detection of burst yesterday
  31. Swift-BAT Trigger 159578 is a possible burst
  32. GRB 051006: Swift/UVOT Upper Limits
  33. GRB051008: optical candidate
  34. GRB 051008 - a low redshift low-luminosity burst?
  35. GRB051011: bright nebulae near error box
  36. GRB051011: MASTER optical observation
  37. GRB051008: Final refined analysis of the Swift-BAT burst
  38. GRB051008: Radio Observation
  39. GRB 051008, optical observations
  40. GRB 051008: early Swift XRT analysis
  41. GRB 051008: Swift UVOT Candidate
  42. GRB 051006: P60 Observations
  43. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  44. GRB 051006: optical observations at Sierra Nevada
  45. GRB051006: Refined analysis of the Swift-BAT burst
  46. GRB051006: Swift detection of a burst
  47. GRB 050906, summary of radio observations
  48. GRB051001: Swift UVOT Upper Limits
  49. GRB 050925: Second Epoch WSRT Radio Observations
  50. GRB 051001: I-band limit
  51. GRB 051001: AAT infra-red observations
  52. GRB 051001: Swift-BAT refined analysis
  53. GRB 051001: Swift Detection of a Burst
  54. GRB 050820A: NIR photometry at the TNG
  55. GRB050925: Swift/XRT limits
  56. GRB/SGR 050925: IR Observations
  57. GRB 050922C: break in the lightcurve
  58. GRB050925: Swift UVOT upper limits
  59. Refined analysis of the Swift-BAT soft short burst
  60. GRB050925: Faulkes Telescope North R-band limit
  61. GRB050925: Swift-BAT detection of a short burst
  62. GRB050922C: TNG spectroscopic observations
  63. GRB050922B: refined XRT analysis
  64. GRB050922B: Swift UVOT early upper limits.
  65. GRB050922C: Optical Observations
  66. GRB 050922C: Swift XRT refined analysis
  67. HETE Fregate observations of GRB 050922C
  68. GRB 050922C: Swift-BAT refined analysis
  69. GRB 050922B: Swift-BAT refined analysis
  70. GRB 050922C: optical obserations
  71. GRB 050922C: NOT optical observations
  72. GRB 050922C: Swift detection of a bright burst
  73. GRB 050922B: ROTSE-III Optical Limits
  74. GRB 050922B,optical observation
  75. GRB050922B: Swift-BAT detection of a weak long burst
  76. GRB050820B: analysis of the XMM-Newton observation
  77. GRB050916: Swift/UVOT Upper Limits
  78. GRB 050916: Swift-BAT refined analysis
  79. Swift-BAT trigger 155764 is not a GRB
  80. Swift-BAT trigger 155764 is probably not a GRB
  81. Swift trigger 155764: bad XRT centroid
  82. Swift-BAT trigger 155535 is definitely not a GRB
  83. GRB050916 : Swift-XRT refined analysis
  84. GRB 050915B: Swift-BAT refined analysis
  85. GRB 050915B: Swift/UVOT Upper Limits
  86. GRB 050915a: IR Transient
  87. GRB 050915b, SMARTS optical/IR observations
  88. GRB050915B: Swift-BAT detection of a long bright burst
  89. GRB050915: Swift/UVOT upper limits
  90. GRB 050915: IR Observations
  91. GRB 050915: Swift XRT refined analysis
  92. GRB 050915: Swift-BAT refined analysis
  93. GRB 050915: Swift detection of a GRB
  94. GRB050911: Upper limit on X-ray afterglow
  95. Swift-BAT trigger 155072 ground analysis
  96. Swift-BAT trigger 155072 is probably not a GRB
  97. GRB 050908: DEIMOS spectrum and further analysis
  98. GRB 050911, optical content of Swift/XRT error box
  99. GRB 050911: Swift-BAT refined analysis
  100. GRB 050911: z~0.16 cluster in the field

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