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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"

16157 results found.

  1. GRB 051022: SSO40 Optical Observations
  2. GRB051022,optical observation
  3. GRB 051022A: ROTSE-III Optical Limits
  4. GRB051022 (=H3590), A GRB Detected By HETE
  5. GRB 051022: Optical observations
  6. GRB 051021,optical observation
  7. GRB051021: Swift XRT analysis
  8. GRB051021 (=H3947): Refined Analysis
  9. GRB 051021 : optical afterglow observation at Lulin
  10. GRB 051021: Optical observations
  11. GRB 051021: ROTSE-III Confirmation of Optical Counterpart
  12. GRB 051021: Optical observations and candidate afterglow
  13. GRB051021.6: MASTER optical observation
  14. GRB051021: A GRB Localized by HETE
  15. GRB 050502b: Optical limit
  16. GRB 051016b: Optical limit
  17. GRB 051016b: Gemini Near IR Observations
  18. GRB 051016B: Swift/UVOT detection
  19. GRB 051016B,optical observation
  20. GRB 051016B : Optical follow-up at Lulin
  21. GRB 051016: LCO optical and near-IR imaging
  22. GRB051006: optical observations
  23. GRB050805A: Rc optical observations
  24. GRB051008: optical candidate
  25. GRB051011: MASTER optical observation
  26. GRB051008: optical observation
  27. GRB 051008, optical observations
  28. GRB 051006: XRT refined analysis
  29. GRB 051006: optical observations at Sierra Nevada
  30. GRB051001: Swift UVOT Upper Limits
  31. GRB 051001, optical observations at Mt. John
  32. GRB 051001: ROTSE-III Optical Limits
  33. GRB050908: optical observations
  34. GRB050922C: optical observation
  35. GRB050922B: optical limit
  36. GRB 050922C: further VLT observations
  37. GRB050922C: UVES/VLT high resolution spectroscopy
  38. GRB050922C - Swift UVOT preliminary analysis
  39. GRB 050922C: break in the lightcurve
  40. GRB050925: Swift UVOT upper limits
  41. GRB050922C: TNG spectroscopic observations
  42. GRB050922B: Swift UVOT early upper limits.
  43. GRB OT observation
  44. GRB050922C: observation at MonteBoo
  45. GRB 050922B: optical limit
  46. GRB050922C: Optical Observations
  47. GRB 050922C: Swift XRT refined analysis
  48. HETE Fregate observations of GRB 050922C
  49. GRB050922C: optical observations
  50. GRB 050922C: Absorption redshift from the Nordic Optical Telescope
  51. GRB 050922C: optical obserations
  52. GRB 050922C: NOT optical observations
  53. GRB 050922C: Swift detection of a bright burst
  54. GRB 050922B: ROTSE-III Optical Limits
  55. GRB 050922B,optical observation
  56. GRB050820B: analysis of the XMM-Newton observation
  57. GRB 050915b, SMARTS optical/IR observations of the XRT position
  58. GRB 050915b, SMARTS optical/IR observations
  59. GRB 050915: KAIT optical limit
  60. GRB050915: P60 Optical Observations
  61. GRB050915, optical observations
  62. GRB 050915: ROTSE-III optical limits
  63. GRB 050911, optical content of Swift/XRT error box
  64. GRB 050911, optical observations
  65. GRB050908: detection of Swift/UVOT optical counterpart
  66. GRB 050910a: TAROT early optical limits
  67. GRB 050906: RTT150 optical observations
  68. GRB050908: Swift/UVOT Early upper limits
  69. GRB050908: VLT R-band decay index.
  70. GRB050908 : Swift-XRT refined analysis
  71. GRB 050908: Swift-BAT refined analysis
  72. GRB 050908: Optical observations
  73. Gemini Spectroscopy of GRB 050908
  74. GRB 050908: spectroscopic redshift
  75. GRB 050908 : Swift XRT position
  76. GRB 050908: P60 Confirmation of Optical Afterglow
  77. GRB 050908: Optical Observations
  78. GRB 050906: Optical observations at the Very Large Telescope
  79. GRB050904: CrAO optical observations
  80. GRB 050904: Subaru Optical Spectroscopy
  81. GRB 050906: MARGE Optical Limits
  82. GRB 050904: more VLT NIR observations
  83. GRB 050906: Swift/BAT Detection of a possible burst
  84. GRB 050904: More SOAR
  85. GRB 050904: Swift/UVOT observations
  86. GRB 050904: SOAR YJ and PROMPT Ic Observations
  87. GRB 050904: BAT refined analysis of partial data set
  88. GRB 050904: TAROT optical measurements
  89. GRB050904: Optical Observations
  90. GRB 050904: Possible High-Redshift GRB
  91. GRB 050904: TAROT optical limits
  92. GRB050904: Swift-BAT detection of a probable burst
  93. GRB 050824: MDM Observations
  94. GRB 050827 : OSN 1.5m optical observations
  95. GRB 050827: Optical Limit
  96. GRB 050826 : Lulin R band observation
  97. GRB050824: Maidanak optical limits
  98. GRB050820A: RTT150 optical observations
  99. GRB050827: RTT150 optical observations
  100. Subaru Observations of GRB050724

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