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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"

33834 results found.

  1. GRB 050915a: IR Transient
  2. GRB 050915B: XRT position
  3. GRB 050915b, SMARTS optical/IR observations
  4. GRB 050915: KAIT optical limit
  5. GRB 050915: IR Observations
  6. GRB 050915: Swift XRT refined analysis
  7. GRB 050915: Swift-BAT refined analysis
  8. GRB050915: P60 Optical Observations
  9. GRB 050915: ROTSE-III optical limits
  10. GRB 050915: Swift detection of a GRB
  11. GRB050911: Upper limit on X-ray afterglow
  12. Swift-BAT trigger 155072 ground analysis
  13. Swift-BAT trigger 155072 is probably not a GRB
  14. GRB 050911: LCO limits on a variable source
  15. GRB 050908: DEIMOS spectrum and further analysis
  16. Swift is in normal operation
  17. GRB 050911, optical content of Swift/XRT error box
  18. GRB 050911: LCO observations
  19. GRB 050911, optical observations
  20. GRB 050911: Swift-BAT refined analysis
  21. Later Swift-BAT triggers 154632 and 154633 RETRACTION
  22. GRB 050911: z~0.16 cluster in the field
  23. GRB 050910a: TAROT early optical limits
  24. RBO GRB 050908 observations
  25. WIRO observations in I of GRB 050908
  26. GRB 050906: Possible X-ray Counterpart
  27. GRB 050906: RTT150 optical observations
  28. GRB050908: VLT R-band decay index.
  29. GRB 050908: Swift-BAT refined analysis
  30. GRB 050908: Optical observations
  31. Gemini Spectroscopy of GRB 050908
  32. GRB 050908: spectroscopic redshift
  33. GRB 050908: Prompt PROMPT Observations
  34. GRB 050908 : Swift XRT position
  35. GRB 050908: KAIT observations
  36. GRB 050908: P60 Confirmation of Optical Afterglow
  37. GRB 050908: Optical Observations
  38. GRB 050908: Swift detection of a burst
  39. Swift trigger 154073 is not a GRB
  40. GRB 050906: Optical observations at the Very Large Telescope
  41. GRB050904: CrAO optical observations
  42. GRB 050904 BAT refined analysis of complete data set
  43. GRB 050904: Subaru Optical Spectroscopy
  44. GRB 050906: MARGE Optical Limits
  45. GRB 050906: Swift-BAT refined analysis
  46. GRB 050906: Swift XRT upper limit
  47. GRB 050906: Radio Observations
  48. GRB 050904: Keck I-band Imaging
  49. GRB 050904: more VLT NIR observations
  50. GRB 050904: BOOTES early R-band observation
  51. GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
  52. GRB 050906: Bright galaxy in BAT error box
  53. GRB 050906: Swift/BAT Detection of a possible burst
  54. GRB 050904: More SOAR
  55. GRB 050904: photometric redshift
  56. GRB 050904: Swift/UVOT observations
  57. GRB 050904: Afterglow Astrometry
  58. GRB 050904: NIR object inside the XRT error box
  59. GRB 050904: early Swift XRT analysis results
  60. GRB 050904: SOAR YJ and PROMPT Ic Observations
  61. GRB 050904: BAT refined analysis of partial data set
  62. GRB 050904: TAROT optical measurements
  63. GRB050904: Optical Observations
  64. GRB 050904: Environmental Constraints
  65. GRB 050904: Possible High-Redshift GRB
  66. GRB 050904: SOAR/PROMPT Observations
  67. GRB 050904: TAROT optical limits
  68. Swift-BAT triggers 153461-153465 are not GRBs
  69. GRB 050824: MDM Observations
  70. GRB 050827: Swift XRT preliminary analysis results
  71. IBAS Alerts 2641 and 2642: not a real GRB
  72. Swift Trigger #152652 is not a GRB
  73. GRB 050827 : OSN 1.5m optical observations
  74. GRB 050827: P200 NIR Observations
  75. GRB 050827: Optical Limit
  76. GRB 050827: XRT possible afterglow detection
  77. GRB 050826 : Lulin R band observation
  78. GRB050824: Maidanak optical limits
  79. GRB050820A: RTT150 optical observations
  80. GRB050827: RTT150 optical observations
  81. GRB 050827: Swift-BAT refined analysis
  82. GRB 050826: Optical Candidate
  83. GRB050824, HETE-2 Observation
  84. GRB 050826: Swift XRT preliminary analysis results
  85. GRB 050826: BAT refined analysis
  86. GRB050824: First 2 hours of power low optical decay?
  87. GRB 050826: Swift XRT position
  88. GRB050826: Swift-BAT detection of a long burst
  89. GRB050824: MASTER final analysis of the OT observations
  90. Possible GRB050825:MASTER optical observations
  91. Swift-BAT trigger 152038 is definitely not a GRB
  92. Swift-BAT trigger 152038 is probably not a GRB
  93. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  94. GRB050824, I-band imaging
  95. GRB050824: Radio Observations
  96. GRB 050824: Spectroscopic redshift from the VLT
  97. GRB 050822: refined XRT analysis
  98. GRB 050824: XRT refined analysis and possible afterglow detection
  99. GRB 050824: BAT refined analysis of a soft weak burst
  100. GRB050824: MASTER:OT decay

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