Technique Total|Mean Sep. (as)|Median Sep. (as) A Adaptive Optics 24427 3.154 1.189 C CCD (long focus) 117651 21.010 8.900 D Heliometer 1732 31.211 10.525 E Wide-field CCD 569797 46.127 14.640 H Space-based technique 645825 41.094 8.749 I Interferometry 907 0.273 0.164 J Visual Interferometer 4181 0.213 0.128 K Long-Baseline Interferometer 5229 0.426 0.047 M Micrometer 425375 10.252 2.140 O Occultation 2450 0.578 0.100 P Photography 186317 33.088 13.349 S Speckle Interferometer 137026 1.260 0.475 T Transit Instrument 10917 145.782 42.040 V Visual Estimate 62 54.657 12.600 X Spectroscopy 536 14.060 10.000 Z Photometer 100027 37.102 19.480 - Unknown 2402 76.904 13.900