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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"

18478 results found.

  1. GRB051006: Refined analysis of the Swift-BAT burst
  2. GRB 051006: XRT position
  3. GRB051006: Swift detection of a burst
  4. GRB 050906, summary of radio observations
  5. GRB051001: Swift UVOT Upper Limits
  6. GRB 051001, optical observations at Mt. John
  7. GRB 051001: AAT infra-red observations
  8. GRB 051001: Swift Detection of a Burst
  9. GRB050908: optical observations
  10. GRB 050820A: NIR photometry at the TNG
  11. GRB/SGR 050925: IR Observations
  12. GRB050925: Swift UVOT upper limits
  13. Refined analysis of the Swift-BAT soft short burst
  14. GRB050925: Faulkes Telescope North R-band limit
  15. GRB050925: Swift-BAT detection of a short burst
  16. GRB050922B: Swift UVOT early upper limits.
  17. INT 2.5m limit for GRB050922B
  18. GRB 050922C: Swift XRT refined analysis
  19. GRB 050922C: Swift-BAT refined analysis
  20. GRB 050922C: optical obserations
  21. GRB 050922C: NOT optical observations
  22. GRB 050922C: Swift detection of a bright burst
  23. GRB 050922B: ROTSE-III Optical Limits
  24. GRB 050922B,optical observation
  25. GRB050922B: Swift-BAT detection of a weak long burst
  26. GRB050820B: analysis of the XMM-Newton observation
  27. GRB050916: Swift/UVOT Upper Limits
  28. Swift-BAT trigger 155764 is not a GRB
  29. Swift-BAT trigger 155764 is probably not a GRB
  30. Swift trigger 155764: bad XRT centroid
  31. Swift-BAT trigger 155535 is definitely not a GRB
  32. GRB050916 : Swift-XRT refined analysis
  33. GRB 050916: XRT position
  34. GRB 050915B: Swift-BAT refined analysis
  35. GRB 050915B: Swift/UVOT Upper Limits
  36. GRB 050915a: IR Transient
  37. GRB 050915B: XRT position
  38. GRB 050915b, SMARTS optical/IR observations
  39. GRB050915B: Swift-BAT detection of a long bright burst
  40. GRB050915: Swift/UVOT upper limits
  41. GRB 050915: IR Observations
  42. GRB 050915: Swift-BAT refined analysis
  43. GRB050915: XRT position
  44. GRB 050915: Swift detection of a GRB
  45. Swift-BAT trigger 155072 is probably not a GRB
  46. GRB 050911: z~0.16 cluster in the field
  47. GRB050911: Swift-BAT detection of a long burst
  48. GRB 050910a: TAROT early optical limits
  49. GRB 050906: Possible X-ray Counterpart
  50. GRB050908: Swift/UVOT Early upper limits
  51. GRB050908 : Swift-XRT refined analysis
  52. GRB 050908: Swift-BAT refined analysis
  53. GRB 050908: Optical observations
  54. GRB 050908: spectroscopic redshift
  55. GRB 050908: Swift detection of a burst
  56. Swift trigger 154073 is not a GRB
  57. GRB 050906: Optical observations at the Very Large Telescope
  58. GRB 050904: Subaru Optical Spectroscopy
  59. GRB 050906: Swift-BAT refined analysis
  60. GRB 050906: Swift XRT upper limit
  61. GRB 050904: Keck I-band Imaging
  62. GRB050906: P60 Observations
  63. GRB 050904: photometric redshift
  64. GRB 050904: Swift/UVOT observations
  65. GRB 050904: NIR object inside the XRT error box
  66. GRB 050904: TAROT optical measurements
  67. GRB050904: Optical Observations
  68. GRB 050904: Environmental Constraints
  69. GRB050904: P60 Observations
  70. GRB 050904: TAROT optical limits
  71. GRB 050827 : OSN 1.5m optical observations
  72. GRB 050827: P200 NIR Observations
  73. GRB050827: Swift/UVOT upper limits
  74. GRB 050827: XRT possible afterglow detection
  75. GRB050824: Maidanak optical limits
  76. Subaru Observations of GRB050724
  77. GRB 050826: Optical Candidate
  78. GRB 050826: BAT refined analysis
  79. GRB050826: Swift/UVOT early upper limits
  80. GRB 050826: Swift XRT position
  81. GRB050826: Swift-BAT detection of a long burst
  82. XRF050509c: Radio upper limits from GMRT
  83. GRB050822: Swift/UVOT upper limits
  84. GRB050813: Maidanak I-band observations
  85. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  86. GRB050820B at FRAM
  87. Swift/UVOT UV Photometry of GRB 050820B
  88. GRB 050822: Swift detection of a long burst
  89. GRB050820a BVRcIc field photometry
  90. GRB050820B XMM-Newton observation
  91. GRB 050820B: Swift XRT position
  92. GRB050820B: Refined analysis of the Swift-BAT burst
  93. GRB050820: refined XRT analysis
  94. GRB 050820: Early RAPTOR detections
  95. GRB050819: refined XRT analysis
  96. GRB 050820: Swift detection of a GRB
  97. GRB050819: Swift XRT position
  98. GRB050819: Swift-BAT detection of a weak burst
  99. GRB 050817: Optical observations
  100. GRB 050814: continued fading

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