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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"

19387 results found.

  1. GRB 051006: Swift/UVOT Upper Limits
  2. GRB051011: MASTER optical observation
  3. Konus-Wind observation of GRB 051008
  4. GRB051008: Radio Observation
  5. GRB 051008, optical observations
  6. GRB 051008: early Swift XRT analysis
  7. GRB 051008: Swift UVOT Candidate
  8. GRB 051006: P60 Observations
  9. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  10. GRB051006: Refined analysis of the Swift-BAT burst
  11. GRB051006: Swift detection of a burst
  12. GRB 050906, summary of radio observations
  13. GRB051001: Swift UVOT Upper Limits
  14. GRB 051001: AAT infra-red observations
  15. GRB 051001: Swift Detection of a Burst
  16. GRB 051001: ROTSE-III Optical Limits
  17. GRB 050820A: NIR photometry at the TNG
  18. GRB/SGR 050925: IR Observations
  19. GRB050925: Swift UVOT upper limits
  20. GRB050925: Faulkes Telescope North R-band limit
  21. GRB050925: Swift-BAT detection of a short burst
  22. GRB050922C: TNG spectroscopic observations
  23. Konus-Wind observation of GRB 050922C
  24. GRB050922B: Swift UVOT early upper limits.
  25. GRB050922C: Optical Observations
  26. GRB 050922C: Swift-BAT refined analysis
  27. GRB 050922C: optical obserations
  28. GRB 050922C: NOT optical observations
  29. GRB 050922C: Swift detection of a bright burst
  30. GRB 050922C: ROTSE-IIId Refined Analysis
  31. GRB 050922B: ROTSE-III Optical Limits
  32. GRB 050922B,optical observation
  33. GRB050922B: Swift-BAT detection of a weak long burst
  34. GRB050918: Possible Swift/XRT detected afterglow
  35. GRB050820B: analysis of the XMM-Newton observation
  36. GRB050916: Swift/UVOT Upper Limits
  37. Swift-BAT trigger 155764 is not a GRB
  38. Swift-BAT trigger 155764 is probably not a GRB
  39. Swift trigger 155764: bad XRT centroid
  40. Swift-BAT trigger 155535 is definitely not a GRB
  41. GRB050916 : Swift-XRT refined analysis
  42. GRB 050915B: Swift/UVOT Upper Limits
  43. GRB 050915a: IR Transient
  44. GRB 050915b, SMARTS optical/IR observations
  45. GRB050915B: Swift-BAT detection of a long bright burst
  46. GRB050915: Swift/UVOT upper limits
  47. GRB 050915: IR Observations
  48. GRB 050915: ROTSE-III optical limits
  49. GRB 050915: Swift detection of a GRB
  50. Swift-BAT trigger 155072 ground analysis
  51. Swift-BAT trigger 155072 is probably not a GRB
  52. GRB 050911, optical observations
  53. GRB 050911: z~0.16 cluster in the field
  54. GRB050911: Swift-BAT detection of a long burst
  55. GRB 050910a: TAROT early optical limits
  56. GRB 050906: Possible X-ray Counterpart
  57. GRB050908: Swift/UVOT Early upper limits
  58. GRB050908 : Swift-XRT refined analysis
  59. GRB 050908: Optical observations
  60. GRB 050908: Optical Observations
  61. GRB 050908: Swift detection of a burst
  62. GRB 050906: Optical observations at the Very Large Telescope
  63. GRB 050904: Subaru Optical Spectroscopy
  64. GRB 050906: Swift XRT upper limit
  65. GRB 050904: Keck I-band Imaging
  66. GRB050906: P60 Observations
  67. GRB 050904: photometric redshift
  68. GRB 050904: Swift/UVOT observations
  69. GRB 050904: NIR object inside the XRT error box
  70. GRB050904: Optical Observations
  71. GRB050904: P60 Observations
  72. GRB 050904: TAROT optical limits
  73. GRB 050827: P200 NIR Observations
  74. GRB050827: Swift/UVOT upper limits
  75. GRB050824: Maidanak optical limits
  76. GRB050820A: RTT150 optical observations
  77. Subaru Observations of GRB050724
  78. GRB050826: Swift/UVOT early upper limits
  79. GRB050826: Swift-BAT detection of a long burst
  80. GRB050824: CORRECTION to UVOT observing times
  81. GRB050824: Swift/UVOT detection of fading afterglow
  82. GRB 050824: BAT refined analysis of a soft weak burst
  83. GRB050824: MASTER observation OT
  84. GRB050805a: MASTER optical candidat
  85. GRB 050824: ROTSE-III Optical Limits
  86. GRB050820a: PROMPT RcIc Observations
  87. XRF050509c: Radio upper limits from GMRT
  88. GRB050822: Swift/UVOT upper limits
  89. GRB 050820A BAT observations of second, larger episode of emission
  90. GRB050813: Maidanak I-band observations
  91. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  92. GRB050820B at FRAM
  93. Swift/UVOT UV Photometry of GRB 050820B
  94. GRB 050822: ROTSE-III Prompt Optical Limits
  95. GRB 050822: Swift detection of a long burst
  96. GRB050820a BVRcIc field photometry
  97. GRB050820B XMM-Newton observation
  98. GRB 050820B: Swift XRT position
  99. Swift/UVOT photometry of GRB050820
  100. GRB050820: refined XRT analysis

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