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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"

28083 results found.

  1. GRB051021.6: MASTER optical observation
  2. GRB051021: A GRB Localized by HETE
  3. Swift-BAT triggered on a posible CR Shower or possible GRB
  4. GRB 051016b: Optical limit
  5. Afterglow candidate of GRB 051016B observed at Lulin
  6. GRB 051016A: Swift/UVOT upper limits
  7. GRB 051016B: refined analysis of the Swift/XRT data
  8. GRB 051016B: Swift/UVOT detection
  9. GRB 051016B,optical observation
  10. GRB 051016B : Optical follow-up at Lulin
  11. GRB 051016B: Refined analysis of the Swift-BAT burst
  12. GRB 051016B: Swift detection of a soft burst
  13. GRB 051016: Swift-BAT refined analysis
  14. GRB051016 XMM-Newton observation
  15. GRB051016: Swift XRT refined analysis.
  16. GRB 051016: PROMPT Observations
  17. GRB051016: Swift detection of a burst
  18. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  19. GRB 051012: Swift-BAT detection of burst yesterday
  20. Swift-BAT Trigger 159578 is a possible burst
  21. GRB 051006: Swift/UVOT Upper Limits
  22. GRB051008: optical candidate
  23. GRB 051008 - a low redshift low-luminosity burst?
  24. GRB051011: bright nebulae near error box
  25. GRB051011: MASTER optical observation
  26. GRB051008: Final refined analysis of the Swift-BAT burst
  27. GRB051008: Radio Observation
  28. GRB 051008, optical observations
  29. GRB 051008: early Swift XRT analysis
  30. GRB 051008: Swift UVOT Candidate
  31. GRB 051006: P60 Observations
  32. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  33. GRB 051006: optical observations at Sierra Nevada
  34. GRB051006: Refined analysis of the Swift-BAT burst
  35. GRB051006: Swift detection of a burst
  36. GRB 050906, summary of radio observations
  37. GRB051001: Swift UVOT Upper Limits
  38. GRB 050925: Second Epoch WSRT Radio Observations
  39. GRB 051001: I-band limit
  40. GRB 051001: AAT infra-red observations
  41. GRB 051001: Swift-BAT refined analysis
  42. GRB 051001: Swift Detection of a Burst
  43. GRB 050820A: NIR photometry at the TNG
  44. GRB050925: Swift/XRT limits
  45. GRB/SGR 050925: IR Observations
  46. GRB 050922C: break in the lightcurve
  47. GRB050925: Swift UVOT upper limits
  48. Refined analysis of the Swift-BAT soft short burst
  49. GRB050925: Faulkes Telescope North R-band limit
  50. GRB050925: Swift-BAT detection of a short burst
  51. GRB050922C: TNG spectroscopic observations
  52. GRB050922B: refined XRT analysis
  53. GRB050922B: Swift UVOT early upper limits.
  54. GRB050922C: Optical Observations
  55. GRB 050922C: Swift XRT refined analysis
  56. HETE Fregate observations of GRB 050922C
  57. GRB 050922C: Swift-BAT refined analysis
  58. GRB 050922B: Swift-BAT refined analysis
  59. GRB 050922C: optical obserations
  60. GRB 050922C: NOT optical observations
  61. GRB 050922C: Swift detection of a bright burst
  62. GRB 050922B: ROTSE-III Optical Limits
  63. GRB 050922B,optical observation
  64. GRB050922B: Swift-BAT detection of a weak long burst
  65. GRB050820B: analysis of the XMM-Newton observation
  66. GRB050916: Swift/UVOT Upper Limits
  67. GRB 050916: Swift-BAT refined analysis
  68. Swift-BAT trigger 155764 is not a GRB
  69. Swift-BAT trigger 155764 is probably not a GRB
  70. Swift trigger 155764: bad XRT centroid
  71. Swift-BAT trigger 155535 is definitely not a GRB
  72. GRB050916 : Swift-XRT refined analysis
  73. GRB 050915B: Swift-BAT refined analysis
  74. GRB 050915B: Swift/UVOT Upper Limits
  75. GRB 050915a: IR Transient
  76. GRB 050915b, SMARTS optical/IR observations
  77. GRB050915B: Swift-BAT detection of a long bright burst
  78. GRB050915: Swift/UVOT upper limits
  79. GRB 050915: IR Observations
  80. GRB 050915: Swift XRT refined analysis
  81. GRB 050915: Swift-BAT refined analysis
  82. GRB 050915: Swift detection of a GRB
  83. GRB050911: Upper limit on X-ray afterglow
  84. Swift-BAT trigger 155072 ground analysis
  85. Swift-BAT trigger 155072 is probably not a GRB
  86. GRB 050908: DEIMOS spectrum and further analysis
  87. GRB 050911, optical content of Swift/XRT error box
  88. GRB 050911: Swift-BAT refined analysis
  89. GRB 050911: z~0.16 cluster in the field
  90. GRB050911: Swift-BAT detection of a long burst
  91. GRB 050910a: TAROT early optical limits
  92. WIRO observations in I of GRB 050908
  93. GRB 050906: Possible X-ray Counterpart
  94. GRB050908: Swift/UVOT Early upper limits
  95. GRB050908 : Swift-XRT refined analysis
  96. GRB 050908: Swift-BAT refined analysis
  97. GRB 050908: Optical observations
  98. GRB 050908: Optical Observations
  99. GRB 050908: Swift detection of a burst
  100. GRB 050906: Optical observations at the Very Large Telescope

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