Technique Total|Mean Sep. (as)|Median Sep. (as) A Adaptive Optics 24421 3.154 1.190 C CCD (long focus) 117068 20.931 8.890 D Heliometer 1732 31.211 10.525 E Wide-field CCD 569654 46.130 14.640 H Space-based technique 643537 41.146 8.757 I Interferometry 907 0.273 0.164 J Visual Interferometer 4181 0.213 0.128 K Long-Baseline Interferometer 5165 0.428 0.048 M Micrometer 425348 10.250 2.140 O Occultation 2443 0.580 0.100 P Photography 185631 32.982 13.308 S Speckle Interferometer 135592 1.268 0.479 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 99995 37.102 19.480 - Unknown 2409 76.620 13.885