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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"

21795 results found.

  1. GRB 051016B: Swift/UVOT detection
  2. GRB 051016B,optical observation
  3. GRB 051016B: Swift detection of a soft burst
  4. GRB051016 XMM-Newton observation
  5. GRB 051016: PROMPT Observations
  6. GRB051016: Swift detection of a burst
  7. GRB051006: optical observations
  8. GRB 051012: Swift-BAT detection of burst yesterday
  9. GRB 051006: Swift/UVOT Upper Limits
  10. GRB051011: MASTER optical observation
  11. Konus-Wind observation of GRB 051008
  12. GRB051008: Radio Observation
  13. GRB 051008, optical observations
  14. GRB 051008: early Swift XRT analysis
  15. GRB 051008: Swift UVOT Candidate
  16. GRB 051006: P60 Observations
  17. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  18. GRB051006: Refined analysis of the Swift-BAT burst
  19. GRB051006: Swift detection of a burst
  20. GRB 050906, summary of radio observations
  21. GRB051001: Swift UVOT Upper Limits
  22. GRB 051001: AAT infra-red observations
  23. GRB 051001: Swift Detection of a Burst
  24. GRB 051001: ROTSE-III Optical Limits
  25. GRB 050820A: NIR photometry at the TNG
  26. GRB/SGR 050925: IR Observations
  27. GRB050925: Swift UVOT upper limits
  28. GRB050925: Faulkes Telescope North R-band limit
  29. GRB050925: Swift-BAT detection of a short burst
  30. GRB050922C: TNG spectroscopic observations
  31. Konus-Wind observation of GRB 050922C
  32. GRB050922B: Swift UVOT early upper limits.
  33. GRB050922C: Optical Observations
  34. GRB 050922C: Swift-BAT refined analysis
  35. GRB 050922C: optical obserations
  36. GRB 050922C: NOT optical observations
  37. GRB 050922C: Swift detection of a bright burst
  38. GRB 050922C: ROTSE-IIId Refined Analysis
  39. GRB 050922B: ROTSE-III Optical Limits
  40. GRB 050922B,optical observation
  41. GRB050922B: Swift-BAT detection of a weak long burst
  42. GRB050918: Possible Swift/XRT detected afterglow
  43. GRB050820B: analysis of the XMM-Newton observation
  44. GRB050916: Swift/UVOT Upper Limits
  45. Swift-BAT trigger 155764 is not a GRB
  46. Swift-BAT trigger 155764 is probably not a GRB
  47. Swift trigger 155764: bad XRT centroid
  48. Swift-BAT trigger 155535 is definitely not a GRB
  49. GRB050916 : Swift-XRT refined analysis
  50. GRB 050915B: Swift/UVOT Upper Limits
  51. GRB 050915a: IR Transient
  52. GRB 050915b, SMARTS optical/IR observations
  53. GRB050915B: Swift-BAT detection of a long bright burst
  54. GRB050915: Swift/UVOT upper limits
  55. GRB 050915: IR Observations
  56. GRB 050915: ROTSE-III optical limits
  57. GRB 050915: Swift detection of a GRB
  58. Swift-BAT trigger 155072 ground analysis
  59. Swift-BAT trigger 155072 is probably not a GRB
  60. GRB 050911, optical observations
  61. GRB 050911: z~0.16 cluster in the field
  62. GRB050911: Swift-BAT detection of a long burst
  63. GRB 050910a: TAROT early optical limits
  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. GRB 050908: Optical Observations
  69. GRB 050908: Swift detection of a burst
  70. GRB 050906: Optical observations at the Very Large Telescope
  71. GRB 050904: Subaru Optical Spectroscopy
  72. GRB 050906: Swift XRT upper limit
  73. GRB 050904: Keck I-band Imaging
  74. GRB050906: P60 Observations
  75. GRB 050904: photometric redshift
  76. GRB 050904: Swift/UVOT observations
  77. GRB 050904: NIR object inside the XRT error box
  78. GRB050904: Optical Observations
  79. GRB050904: P60 Observations
  80. GRB 050904: TAROT optical limits
  81. GRB 050827: P200 NIR Observations
  82. GRB050827: Swift/UVOT upper limits
  83. GRB050824: Maidanak optical limits
  84. GRB050820A: RTT150 optical observations
  85. Subaru Observations of GRB050724
  86. GRB050826: Swift/UVOT early upper limits
  87. GRB050826: Swift-BAT detection of a long burst
  88. GRB050824: CORRECTION to UVOT observing times
  89. GRB050824: Swift/UVOT detection of fading afterglow
  90. GRB 050824: BAT refined analysis of a soft weak burst
  91. GRB050824: MASTER observation OT
  92. GRB050805a: MASTER optical candidat
  93. GRB 050824: ROTSE-III Optical Limits
  94. GRB050820a: PROMPT RcIc Observations
  95. XRF050509c: Radio upper limits from GMRT
  96. GRB050822: Swift/UVOT upper limits
  97. GRB 050820A BAT observations of second, larger episode of emission
  98. GRB050813: Maidanak I-band observations
  99. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  100. GRB050820B at FRAM

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