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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"

28089 results found.

  1. GRB051022,optical observation
  2. GRB 051021,optical observation
  3. GRB 051021B: Swift detection of a burst
  4. GRB 051021 : optical afterglow observation at Lulin
  5. GRB 051021: Optical observations and candidate afterglow
  6. GRB051021.63
  7. GRB051021.6: MASTER optical observation
  8. GRB051021: A GRB Localized by HETE
  9. Swift-BAT triggered on a posible CR Shower or possible GRB
  10. GRB 051016b: Optical limit
  11. Afterglow candidate of GRB 051016B observed at Lulin
  12. GRB 051016A: Swift/UVOT upper limits
  13. GRB 051016B: refined analysis of the Swift/XRT data
  14. GRB 051016B: Swift/UVOT detection
  15. GRB 051016B,optical observation
  16. GRB 051016B : Optical follow-up at Lulin
  17. GRB 051016B: Refined analysis of the Swift-BAT burst
  18. GRB 051016B: Swift detection of a soft burst
  19. GRB 051016: Swift-BAT refined analysis
  20. GRB051016 XMM-Newton observation
  21. GRB051016: Swift XRT refined analysis.
  22. GRB 051016: PROMPT Observations
  23. GRB051016: Swift detection of a burst
  24. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  25. GRB 051012: Swift-BAT detection of burst yesterday
  26. Swift-BAT Trigger 159578 is a possible burst
  27. GRB 051006: Swift/UVOT Upper Limits
  28. GRB051008: optical candidate
  29. GRB 051008 - a low redshift low-luminosity burst?
  30. GRB051011: bright nebulae near error box
  31. GRB051011: MASTER optical observation
  32. GRB051008: Final refined analysis of the Swift-BAT burst
  33. GRB051008: Radio Observation
  34. GRB 051008, optical observations
  35. GRB 051008: early Swift XRT analysis
  36. GRB 051008: Swift UVOT Candidate
  37. GRB 051006: P60 Observations
  38. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  39. GRB 051006: optical observations at Sierra Nevada
  40. GRB051006: Refined analysis of the Swift-BAT burst
  41. GRB051006: Swift detection of a burst
  42. GRB 050906, summary of radio observations
  43. GRB051001: Swift UVOT Upper Limits
  44. GRB 050925: Second Epoch WSRT Radio Observations
  45. GRB 051001: I-band limit
  46. GRB 051001: AAT infra-red observations
  47. GRB 051001: Swift-BAT refined analysis
  48. GRB 051001: Swift Detection of a Burst
  49. GRB 050820A: NIR photometry at the TNG
  50. GRB050925: Swift/XRT limits
  51. GRB/SGR 050925: IR Observations
  52. GRB 050922C: break in the lightcurve
  53. GRB050925: Swift UVOT upper limits
  54. Refined analysis of the Swift-BAT soft short burst
  55. GRB050925: Faulkes Telescope North R-band limit
  56. GRB050925: Swift-BAT detection of a short burst
  57. GRB050922C: TNG spectroscopic observations
  58. GRB050922B: refined XRT analysis
  59. GRB050922B: Swift UVOT early upper limits.
  60. GRB050922C: Optical Observations
  61. GRB 050922C: Swift XRT refined analysis
  62. HETE Fregate observations of GRB 050922C
  63. GRB 050922C: Swift-BAT refined analysis
  64. GRB 050922B: Swift-BAT refined analysis
  65. GRB 050922C: optical obserations
  66. GRB 050922C: NOT optical observations
  67. GRB 050922C: Swift detection of a bright burst
  68. GRB 050922B: ROTSE-III Optical Limits
  69. GRB 050922B,optical observation
  70. GRB050922B: Swift-BAT detection of a weak long burst
  71. GRB050820B: analysis of the XMM-Newton observation
  72. GRB050916: Swift/UVOT Upper Limits
  73. GRB 050916: Swift-BAT refined analysis
  74. Swift-BAT trigger 155764 is not a GRB
  75. Swift-BAT trigger 155764 is probably not a GRB
  76. Swift trigger 155764: bad XRT centroid
  77. Swift-BAT trigger 155535 is definitely not a GRB
  78. GRB050916 : Swift-XRT refined analysis
  79. GRB 050915B: Swift-BAT refined analysis
  80. GRB 050915B: Swift/UVOT Upper Limits
  81. GRB 050915a: IR Transient
  82. GRB 050915b, SMARTS optical/IR observations
  83. GRB050915B: Swift-BAT detection of a long bright burst
  84. GRB050915: Swift/UVOT upper limits
  85. GRB 050915: IR Observations
  86. GRB 050915: Swift XRT refined analysis
  87. GRB 050915: Swift-BAT refined analysis
  88. GRB 050915: Swift detection of a GRB
  89. GRB050911: Upper limit on X-ray afterglow
  90. Swift-BAT trigger 155072 ground analysis
  91. Swift-BAT trigger 155072 is probably not a GRB
  92. GRB 050908: DEIMOS spectrum and further analysis
  93. GRB 050911, optical content of Swift/XRT error box
  94. GRB 050911: Swift-BAT refined analysis
  95. GRB 050911: z~0.16 cluster in the field
  96. GRB050911: Swift-BAT detection of a long burst
  97. GRB 050910a: TAROT early optical limits
  98. WIRO observations in I of GRB 050908
  99. GRB 050906: Possible X-ray Counterpart
  100. GRB050908: Swift/UVOT Early upper limits

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