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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"

20359 results found.

  1. GRB051021B: Swift XRT Position
  2. GRB 051021B: Swift detection of a burst
  3. GRB051021: Swift XRT analysis
  4. Swift-BAT triggered on a posible CR Shower or possible GRB
  5. Afterglow candidate of GRB 051016B observed at Lulin
  6. GRB 051016b: Gemini Near IR Observations
  7. GRB 051016A: Swift/UVOT upper limits
  8. GRB 051016B: Swift/UVOT detection
  9. GRB 051016B,optical observation
  10. GRB 051016B: Swift detection of a soft burst
  11. GRB051016 XMM-Newton observation
  12. GRB 051016: PROMPT Observations
  13. GRB051016: Swift detection of a burst
  14. GRB 051012: Swift-BAT detection of burst yesterday
  15. GRB 051006: Swift/UVOT Upper Limits
  16. Konus-Wind observation of GRB 051008
  17. GRB051008: Radio Observation
  18. GRB 051008, optical observations
  19. GRB 051008: early Swift XRT analysis
  20. GRB 051008: Swift UVOT Candidate
  21. GRB051008: Swift-BAT detection of a bright burst
  22. GRB 051006: P60 Observations
  23. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  24. GRB051006: Swift detection of a burst
  25. GRB 050906, summary of radio observations
  26. GRB051001: Swift UVOT Upper Limits
  27. GRB 051001: AAT infra-red observations
  28. GRB 051001: Swift Detection of a Burst
  29. GRB 050820A: NIR photometry at the TNG
  30. GRB/SGR 050925: IR Observations
  31. GRB050925: Swift UVOT upper limits
  32. GRB050925: Faulkes Telescope North R-band limit
  33. GRB050925: Swift-BAT detection of a short burst
  34. GRB050922B: refined XRT analysis
  35. GRB050922B: Swift UVOT early upper limits.
  36. GRB 050922C: optical obserations
  37. GRB 050922C: NOT optical observations
  38. GRB 050922C: Swift detection of a bright burst
  39. GRB 050922B: ROTSE-III Optical Limits
  40. GRB 050922B,optical observation
  41. GRB050922B: Swift-BAT detection of a weak long burst
  42. GRB050820B: analysis of the XMM-Newton observation
  43. GRB050916: Swift/UVOT Upper Limits
  44. Swift-BAT trigger 155764 is not a GRB
  45. Swift-BAT trigger 155764 is probably not a GRB
  46. Swift trigger 155764: bad XRT centroid
  47. Swift-BAT trigger 155535 is definitely not a GRB
  48. GRB 050915B: Swift-BAT refined analysis
  49. GRB 050915B: Swift/UVOT Upper Limits
  50. GRB 050915a: IR Transient
  51. GRB 050915b, SMARTS optical/IR observations
  52. GRB050915B: Swift-BAT detection of a long bright burst
  53. GRB050915: Swift/UVOT upper limits
  54. GRB 050915: IR Observations
  55. GRB050915: P60 Optical Observations
  56. GRB 050915: Swift detection of a GRB
  57. GRB050911: Upper limit on X-ray afterglow
  58. Swift-BAT trigger 155072 ground analysis
  59. Swift-BAT trigger 155072 is probably not a GRB
  60. GRB 050911: z~0.16 cluster in the field
  61. GRB050911: Swift-BAT detection of a long burst
  62. GRB 050910a: TAROT early optical limits
  63. WIRO observations in I of GRB 050908
  64. GRB 050906: Possible X-ray Counterpart
  65. GRB050908: Swift/UVOT Early upper limits
  66. GRB050908 : Swift-XRT refined analysis
  67. GRB 050908: Optical observations
  68. Gemini Spectroscopy of GRB 050908
  69. GRB 050908: Swift detection of a burst
  70. GRB 050906: Optical observations at the Very Large Telescope
  71. GRB050904: CrAO optical observations
  72. GRB 050904: Subaru Optical Spectroscopy
  73. GRB 050906: Swift XRT upper limit
  74. GRB 050904: Keck I-band Imaging
  75. GRB050906: P60 Observations
  76. GRB 050904: photometric redshift
  77. GRB 050904: Swift/UVOT observations
  78. GRB 050904: NIR object inside the XRT error box
  79. GRB050904: Optical Observations
  80. GRB050904: P60 Observations
  81. GRB 050904: TAROT optical limits
  82. GRB050904: Swift-BAT detection of a probable burst
  83. GRB 050827: P200 NIR Observations
  84. GRB050827: Swift/UVOT upper limits
  85. GRB050824: Maidanak optical limits
  86. GRB 050827: Swift-BAT refined analysis
  87. Subaru Observations of GRB050724
  88. GRB 050826: BAT refined analysis
  89. GRB050826: Swift/UVOT early upper limits
  90. GRB050826: Swift-BAT detection of a long burst
  91. GRB050824, I-band imaging
  92. XRF050509c: Radio upper limits from GMRT
  93. GRB050822: Swift/UVOT upper limits
  94. GRB050813: Maidanak I-band observations
  95. GRB 050822: Swift-BAT refined analysis
  96. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  97. GRB050820B at FRAM
  98. Swift/UVOT UV Photometry of GRB 050820B
  99. GRB 050822: Swift detection of a long burst
  100. GRB050820a BVRcIc field photometry

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