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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"

26366 results found.

  1. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  2. GRB 051012: Swift-BAT detection of burst yesterday
  3. Swift-BAT Trigger 159578 is a possible burst
  4. GRB 051006: Swift/UVOT Upper Limits
  5. GRB051008: optical candidate
  6. GRB 051008 - a low redshift low-luminosity burst?
  7. GRB051011: bright nebulae near error box
  8. GRB051011: MASTER optical observation
  9. GRB051008: Final refined analysis of the Swift-BAT burst
  10. GRB051008: Radio Observation
  11. GRB 051008, optical observations
  12. GRB 051008: early Swift XRT analysis
  13. GRB 051008: Swift UVOT Candidate
  14. GRB 051006: P60 Observations
  15. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  16. GRB 051006: optical observations at Sierra Nevada
  17. GRB051006: Refined analysis of the Swift-BAT burst
  18. GRB051006: Swift detection of a burst
  19. GRB 050906, summary of radio observations
  20. GRB051001: Swift UVOT Upper Limits
  21. GRB 050925: Second Epoch WSRT Radio Observations
  22. GRB 051001: I-band limit
  23. GRB 051001: AAT infra-red observations
  24. GRB 051001: Swift-BAT refined analysis
  25. GRB 051001: Swift Detection of a Burst
  26. GRB 050820A: NIR photometry at the TNG
  27. GRB050925: Swift/XRT limits
  28. GRB/SGR 050925: IR Observations
  29. GRB 050922C: break in the lightcurve
  30. GRB050925: Swift UVOT upper limits
  31. Refined analysis of the Swift-BAT soft short burst
  32. GRB050925: Faulkes Telescope North R-band limit
  33. GRB050925: Swift-BAT detection of a short burst
  34. GRB050922C: TNG spectroscopic observations
  35. GRB050922B: refined XRT analysis
  36. GRB050922B: Swift UVOT early upper limits.
  37. GRB050922C: Optical Observations
  38. GRB 050922C: Swift XRT refined analysis
  39. HETE Fregate observations of GRB 050922C
  40. GRB 050922C: Swift-BAT refined analysis
  41. GRB 050922B: Swift-BAT refined analysis
  42. GRB 050922C: optical obserations
  43. GRB 050922C: NOT optical observations
  44. GRB 050922C: Swift detection of a bright burst
  45. GRB 050922B: ROTSE-III Optical Limits
  46. GRB 050922B,optical observation
  47. GRB050922B: Swift-BAT detection of a weak long burst
  48. GRB050820B: analysis of the XMM-Newton observation
  49. GRB050916: Swift/UVOT Upper Limits
  50. GRB 050916: Swift-BAT refined analysis
  51. Swift-BAT trigger 155764 is not a GRB
  52. Swift-BAT trigger 155764 is probably not a GRB
  53. Swift trigger 155764: bad XRT centroid
  54. Swift-BAT trigger 155535 is definitely not a GRB
  55. GRB050916 : Swift-XRT refined analysis
  56. GRB 050915B: Swift-BAT refined analysis
  57. GRB 050915B: Swift/UVOT Upper Limits
  58. GRB 050915a: IR Transient
  59. GRB 050915b, SMARTS optical/IR observations
  60. GRB050915B: Swift-BAT detection of a long bright burst
  61. GRB050915: Swift/UVOT upper limits
  62. GRB 050915: IR Observations
  63. GRB 050915: Swift XRT refined analysis
  64. GRB 050915: Swift-BAT refined analysis
  65. GRB 050915: Swift detection of a GRB
  66. GRB050911: Upper limit on X-ray afterglow
  67. Swift-BAT trigger 155072 ground analysis
  68. Swift-BAT trigger 155072 is probably not a GRB
  69. GRB 050908: DEIMOS spectrum and further analysis
  70. GRB 050911, optical content of Swift/XRT error box
  71. GRB 050911: Swift-BAT refined analysis
  72. GRB 050911: z~0.16 cluster in the field
  73. GRB050911: Swift-BAT detection of a long burst
  74. GRB 050910a: TAROT early optical limits
  75. WIRO observations in I of GRB 050908
  76. GRB 050906: Possible X-ray Counterpart
  77. GRB050908: Swift/UVOT Early upper limits
  78. GRB050908 : Swift-XRT refined analysis
  79. GRB 050908: Swift-BAT refined analysis
  80. GRB 050908: Optical observations
  81. GRB 050908: Optical Observations
  82. GRB 050908: Swift detection of a burst
  83. GRB 050906: Optical observations at the Very Large Telescope
  84. GRB 050904 BAT refined analysis of complete data set
  85. GRB 050904: Subaru Optical Spectroscopy
  86. GRB 050906: MARGE Optical Limits
  87. GRB 050906: Swift-BAT refined analysis
  88. GRB 050906: Swift XRT upper limit
  89. GRB 050906: Radio Observations
  90. GRB 050904: Keck I-band Imaging
  91. GRB050906: P60 Observations
  92. GRB 050904: more VLT NIR observations
  93. GRB 050904: photometric redshift
  94. GRB 050904: Swift/UVOT observations
  95. GRB 050904: NIR object inside the XRT error box
  96. GRB 050904: early Swift XRT analysis results
  97. GRB 050904: SOAR YJ and PROMPT Ic Observations
  98. GRB050904: Optical Observations
  99. GRB050904: P60 Observations
  100. GRB 050904: TAROT optical limits

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