Technique Total|Mean Sep. (as)|Median Sep. (as) A Adaptive Optics 23669 3.259 1.400 C CCD (long focus) 115482 20.879 8.875 D Heliometer 1702 30.619 10.475 E Wide-field CCD 568847 46.158 14.649 H Space-based technique 639475 40.964 8.766 I Interferometry 907 0.273 0.164 J Visual Interferometer 4180 0.213 0.128 K Long-Baseline Interferometer 4974 0.437 0.051 M Micrometer 425135 10.246 2.140 O Occultation 2383 0.384 0.100 P Photography 183872 32.868 13.250 S Speckle Interferometer 123396 1.007 0.450 T Transit Instrument 10916 145.787 42.022 V Visual Estimate 55 6.771 2.000 X Spectroscopy 536 14.060 10.000 Z Photometer 99748 37.102 19.480 - Unknown 2424 76.215 13.640