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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"

16160 results found.

  1. GRB 051021, SMARTS optical/IR observations
  2. GRB 051022 (=H3950): SXC Flight Localization is Valid
  3. GRB051021: Swift/UVOT Upper Limits
  4. GRB 051022: SSO40 Optical Observations
  5. GRB051022,optical observation
  6. GRB 051022A: ROTSE-III Optical Limits
  7. GRB051022 (=H3590), A GRB Detected By HETE
  8. GRB 051022: Optical observations
  9. GRB 051021,optical observation
  10. GRB051021: Swift XRT analysis
  11. GRB051021 (=H3947): Refined Analysis
  12. GRB 051021 : optical afterglow observation at Lulin
  13. GRB 051021: Optical observations
  14. GRB 051021: ROTSE-III Confirmation of Optical Counterpart
  15. GRB 051021: Optical observations and candidate afterglow
  16. GRB051021.6: MASTER optical observation
  17. GRB051021: A GRB Localized by HETE
  18. GRB 050502b: Optical limit
  19. GRB 051016b: Optical limit
  20. GRB 051016b: Gemini Near IR Observations
  21. GRB 051016B: Swift/UVOT detection
  22. GRB 051016B,optical observation
  23. GRB 051016B : Optical follow-up at Lulin
  24. GRB 051016: LCO optical and near-IR imaging
  25. GRB051006: optical observations
  26. GRB050805A: Rc optical observations
  27. GRB051008: optical candidate
  28. GRB051011: MASTER optical observation
  29. GRB051008: optical observation
  30. GRB 051008, optical observations
  31. GRB 051006: XRT refined analysis
  32. GRB 051006: optical observations at Sierra Nevada
  33. GRB051001: Swift UVOT Upper Limits
  34. GRB 051001, optical observations at Mt. John
  35. GRB 051001: ROTSE-III Optical Limits
  36. GRB050908: optical observations
  37. GRB050922C: optical observation
  38. GRB050922B: optical limit
  39. GRB 050922C: further VLT observations
  40. GRB050922C: UVES/VLT high resolution spectroscopy
  41. GRB050922C - Swift UVOT preliminary analysis
  42. GRB 050922C: break in the lightcurve
  43. GRB050925: Swift UVOT upper limits
  44. GRB050922C: TNG spectroscopic observations
  45. GRB050922B: Swift UVOT early upper limits.
  46. GRB OT observation
  47. GRB050922C: observation at MonteBoo
  48. GRB 050922B: optical limit
  49. GRB050922C: Optical Observations
  50. GRB 050922C: Swift XRT refined analysis
  51. HETE Fregate observations of GRB 050922C
  52. GRB050922C: optical observations
  53. GRB 050922C: Absorption redshift from the Nordic Optical Telescope
  54. GRB 050922C: optical obserations
  55. GRB 050922C: NOT optical observations
  56. GRB 050922C: Swift detection of a bright burst
  57. GRB 050922B: ROTSE-III Optical Limits
  58. GRB 050922B,optical observation
  59. GRB050820B: analysis of the XMM-Newton observation
  60. GRB 050915b, SMARTS optical/IR observations of the XRT position
  61. GRB 050915b, SMARTS optical/IR observations
  62. GRB 050915: KAIT optical limit
  63. GRB050915: P60 Optical Observations
  64. GRB050915, optical observations
  65. GRB 050915: ROTSE-III optical limits
  66. GRB 050911, optical content of Swift/XRT error box
  67. GRB 050911, optical observations
  68. GRB050908: detection of Swift/UVOT optical counterpart
  69. GRB 050910a: TAROT early optical limits
  70. GRB 050906: RTT150 optical observations
  71. GRB050908: Swift/UVOT Early upper limits
  72. GRB050908: VLT R-band decay index.
  73. GRB050908 : Swift-XRT refined analysis
  74. GRB 050908: Swift-BAT refined analysis
  75. GRB 050908: Optical observations
  76. Gemini Spectroscopy of GRB 050908
  77. GRB 050908: spectroscopic redshift
  78. GRB 050908 : Swift XRT position
  79. GRB 050908: P60 Confirmation of Optical Afterglow
  80. GRB 050908: Optical Observations
  81. GRB 050906: Optical observations at the Very Large Telescope
  82. GRB050904: CrAO optical observations
  83. GRB 050904: Subaru Optical Spectroscopy
  84. GRB 050906: MARGE Optical Limits
  85. GRB 050904: more VLT NIR observations
  86. GRB 050906: Swift/BAT Detection of a possible burst
  87. GRB 050904: More SOAR
  88. GRB 050904: Swift/UVOT observations
  89. GRB 050904: SOAR YJ and PROMPT Ic Observations
  90. GRB 050904: BAT refined analysis of partial data set
  91. GRB 050904: TAROT optical measurements
  92. GRB050904: Optical Observations
  93. GRB 050904: Possible High-Redshift GRB
  94. GRB 050904: TAROT optical limits
  95. GRB050904: Swift-BAT detection of a probable burst
  96. GRB 050824: MDM Observations
  97. GRB 050827 : OSN 1.5m optical observations
  98. GRB 050827: Optical Limit
  99. GRB 050826 : Lulin R band observation
  100. GRB050824: Maidanak optical limits

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