Technique Total|Mean Sep. (as)|Median Sep. (as) A Adaptive Optics 24413 3.155 1.190 C CCD (long focus) 116819 20.922 8.895 D Heliometer 1732 31.211 10.525 E Wide-field CCD 569595 46.129 14.640 H Space-based technique 643007 41.171 8.760 I Interferometry 907 0.273 0.164 J Visual Interferometer 4181 0.213 0.128 K Long-Baseline Interferometer 5111 0.434 0.048 M Micrometer 425347 10.250 2.140 O Occultation 2439 0.581 0.100 P Photography 185408 32.962 13.300 S Speckle Interferometer 133949 1.268 0.474 T Transit Instrument 10916 145.787 42.022 V Visual Estimate 62 54.657 12.600 X Spectroscopy 536 14.060 10.000 Z Photometer 99989 37.102 19.480 - Unknown 2410 76.585 13.870