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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"

5544 results found.

  1. GRB 051006: optical observations at Sierra Nevada
  2. GRB 051006: XRT position
  3. GRB/SGR 050925: IR Observations
  4. GRB050922C - Swift UVOT preliminary analysis
  5. GRB050925: Swift UVOT upper limits
  6. GRB050925: Swift-BAT detection of a short burst
  7. GRB050922C: Optical Observations
  8. GRB 050922C: Swift XRT refined analysis
  9. GRB 050922C: Swift-BAT refined analysis
  10. GRB 050922B: Swift-BAT refined analysis
  11. GRB 050922C: NOT optical observations
  12. GRB 050922C: Swift detection of a bright burst
  13. GRB 050922C: ROTSE-III Detection of Possible Counterpart
  14. GRB050916: Swift/UVOT Upper Limits
  15. GRB 050916: XRT position
  16. GRB 050915b, SMARTS optical/IR observations of the XRT position
  17. GRB 050915a: IR Transient
  18. GRB 050915b, SMARTS optical/IR observations
  19. GRB 050915: IR Observations
  20. GRB 050915: Swift detection of a GRB
  21. GRB 050910a: TAROT early optical limits
  22. GRB 050908: Optical observations
  23. GRB050904: Optical Observations
  24. GRB 050904: TAROT optical limits
  25. GRB 050827: P200 NIR Observations
  26. GRB 050827: Optical Limit
  27. GRB050824: MASTER final analysis of the OT observations
  28. GRB050820A: RTT150 optical observations
  29. GRB050820a: PROMPT RcIc Observations
  30. GRB050815: Optical afterglow detection by Swift UVOT
  31. GRB050815: Swift XRT afterglow localization
  32. GRB050815: Swift-BAT detection of a burst
  33. GRB 050807: ROTSE-III Optical Limits
  34. GRB 050730 XMM-Newton observation
  35. GRB 050724: Chandra Observations of the X-ray Afterglow
  36. GRB050724: a short-burst detected by Swift
  37. GRB050712: optical limits
  38. GRB 050713B
  39. GRB 050713 : Planned XMM-Newton observation
  40. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  41. GRB 050701: Swift XRT afterglow position
  42. GRB050607: refined analysis of prompt REM observations
  43. GRB 050607: RAPTOR-S Early Optical Limits
  44. GRB050607: KAIT optical limits
  45. GRB 050607: Optical decay and spectral slope
  46. GRB050607,optical observation
  47. GRB 050607 - XRT refined data analysis
  48. Optical Afterglow of GRB 050607
  49. GRB050607: Swift Detection of a long GRB
  50. GRB050607: P60 Observations
  51. GRB050525: Optical observations
  52. GRB 050520: Swift XRT refined analysis
  53. XRF050509C: Chandra Afterglow Detection
  54. Swift-BAT trigger 122203 is not a real GRB
  55. GRB050502b: Early Observation
  56. GRB 050509b: Swift/UVOT follow-up measurements
  57. GRB050509c (=H3751): An X-Ray Flash Localized By HETE
  58. Swift UVOT Follow-up Observations of GRB 050509B
  59. GRB050509a: Swift UVOT observations
  60. GRB 050509b: Optical observations
  61. GRB 050505: Keck I-band Magnitude
  62. GRB 050505: early time observations
  63. GRB 050505 UVOT
  64. GRB050505: Optical Afterglow Candidate
  65. GRB 050505: Swift XRT Position
  66. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  67. GRB050502b: Afterglow Confirmation
  68. GRB 050502b, V band Observations
  69. GRB 050502a: RBO Observations
  70. GRB050502B Swift-BAT refined analysis
  71. GRB050502B: I band source in XRT error circle
  72. GRB 050502b: Swift XRT Position
  73. Swift Detection of the Bright Burst GRB050502b
  74. GRB050326: analysis of the XMM-Newton observation
  75. GRB 050416,optical observation
  76. GRB 050416: KAIT observations
  77. GRB050408: optical observation
  78. GRB 050408: Subaru Observations
  79. GRB 050408: Mercator Optical Observations
  80. GRB 050408, SMARTS optical/IR afterglow observations
  81. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  82. GRB 050402A: IR Observations
  83. GRB050331: No Afterglow Detected
  84. GRB 050331: Swift UVOT Source
  85. GRB 050331: Swift XRT Position
  86. Konus-Wind observation of GRB 050326
  87. GRB 050326 BAT refined analysis
  88. GRB050326: delayed XRT observation
  89. Swift-BAT detection of a bright GRB 050326
  90. GRB 050319: ROTSE-III Refined Analysis
  91. GRB 050319 R band observations
  92. GRB 050319: Swift-UVOT detection of the afterglow
  93. GRB050319,optical observation
  94. Swift Detection of GRB 050319
  95. GRB050223: analysis of the XMM-Newton observation
  96. GRB 050315, SMARTS optical/IR afterglow observations
  97. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  98. GRB050309: CONCAM pre-trigger and trigger coincident optical
  99. GRB 050306: optical afterglow
  100. GRB 050306: Confirmation of X-ray afterglow

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