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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"
  1. GRB 060614: optical observations
  2. GRB 060605, optical observations
  3. GRB 060614, SMARTS optical/IR afterglow observation
  4. GRB060614: SSO 1m observations
  5. GRB060614: Watcher observation
  6. GRB 060614: Swift-BAT refined analysis
  7. GRB 060614: Swift/UVOT Observations
  8. GRB060614: Swift-XRT refined analysis
  9. GRB 060604, optical observations
  10. GRB 060614: Swift detection of a burst with a bright optical and X-ray counterpart
  11. GRB 060602A: Swift/XRT analysis
  12. BAT Trigger #214277 is SGR 1900+14
  13. GRB 060610: KAIT observations
  14. GRB 060607: RTT150 optical observations
  15. GRB 070706B: Watcher upper limit
  16. GRB 060607B: Swift-BAT Refined Analysis
  17. GRB060602A: Swift/UVOT upper limits
  18. GRB 060607B: Swift detection of a burst
  19. GCN 060607: Swift-UVOT obswervations.
  20. GRB 060607: Swift-BAT Refined Analysis
  21. GRB 060607: optical limit by "Pi of the Sky"
  22. GRB 060607: Swift-XRT Team refined analysis
  23. GRB 060607: IR observations
  24. GRB 060502B: A Bright Early-type Galaxy as Putative Host of the Short Burst
  25. VLT/UVES observations of GRB 060607
  26. GRB 060607: PROMPT Observations
  27. GRB 060605: RTT150 optical observations
  28. GRB 060607: REM NIR afterglow
  29. GRB 060607: Swift detection of a burst with bright optical counterpart
  30. GRB 060522: PROMPT Optical Limits
  31. GRB 060605 BAT refined analysis
  32. GRB 060605: Xinglong TNT optical observations
  33. GRB060602B : REM infrared observations
  34. GRB060605: Swift/UVOT detections
  35. GRB 060605: Swift-XRT Team refined analysis
  36. SALT spectroscopy of GRB 060605
  37. GRB 060605: TNG optical observations
  38. GRB 060605: RTT150 optical observations
  39. GRB060605: Spectral Observations and Redshift
  40. GRB 060605: ROTSE-III Optical Counterpart
  41. GRB 060605: Swift detection of a burst with optical counterpart
  42. GRB 060605: ROTSE-III Detection of Optical Counterpart
  43. GRB060604: Swift/UVOT detections
  44. GRB 060604: redshift
  45. GRB 060512: Keck Redshift
  46. GRB 060604 optical photometry
  47. GRB 060604: Swift-XRT Team refined analysis
  48. GRB 060604: BAT refined analysis
  49. GRB 060604A: ROTSE-III Optical Limits
  50. GRB 060604: Swift detection of a burst with possible optical counterpart
  51. GRB 060602A: Swift-BAT Refined Analysis: Correction
  52. GRB 060602B: XMM-Newton Survey Source
  53. GRB 060602B: Swift-XRT Refined Analysis
  54. GRB 060602B: Swift-BAT Refined Analysis
  55. GRB 060602B: Swift/UVOT observations
  56. GRB 060602A: Swift-BAT Refined Analysis
  57. GRB 060602B: RTT150 optical observations
  58. GRB 060211A : WIDGET simultaneous optical observations
  59. GRB060602A: optical observations(/transient?)
  60. GRB 060526: Tautenburg Second Epoch Observations
  61. GRB060602A: Bootes-IR observations
  62. GRB 060602B: Swift detection of a burst
  63. GRB060602B: Watcher observations - no OT candidate
  64. GRB060602B: BOOTES-IR candidate afterglow
  65. GRB060602 - SDSS Pre-Burst Observations
  66. GRB 060602: Swift detection of a burst
  67. GRB 060502A: Optical afterglow observations
  68. GRB 060526: Break in X-ray light curve
  69. GRB 060526: RTT150 optical observations
  70. GRB060526, optical observations
  71. GRB 051227 : WIDGET simultaneous optical observations
  72. GRB 051028 : WIDGET pre-trigger limit
  73. GRB 060526: RTT150 optical observations
  74. GRB 060526: Multiple Optical Flares
  75. GRB060526: afterglow fitting and probable jet break
  76. GRB 060526: RTT150 optical observations
  77. GRB060526: Optical counterpart from MIRO
  78. GRB060502b: optical observations
  79. GRB 060526: RTT150 optical observations
  80. GRB 060526: Tautenburg OT observation and light curve fitting
  81. GRB060526: optical observations
  82. GRB 060526: SMARTS optical/IR afterglow observations
  83. GRB060526: possible break in the optical light curve
  84. GRB 060526: REM observations
  85. GRB 060526: RTT150 optical observations, afterglow flattening
  86. GRB 060526: Optical Flare
  87. GRB 060526: MDM-2.4m Observations
  88. GRB 060526: Refined analysis of the Swift-BAT burst
  89. GRB 060526: RTT150 optical observations
  90. GRB060526: Further Swift-UVOT Observations
  91. GRB060526, optical observations
  92. GRB 060526: Magellan Redshift
  93. GRB 060526 Lulin optical observation
  94. GRB 060526: Swift/XRT Team refined analysis
  95. GRB 060526: TNG optical observations
  96. GRB 060526: ROTSE-III Observations of Optical Counterpart
  97. GRB 060526: Watcher Observations
  98. GRB060526 - SDSS Pre-burst Observations
  99. GRB 060526: Continued emission for the Swift burst
  100. GRB 060526: Swift detection of a burst with x-ray and optical afterglow

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