Technique Total|Mean Sep. (as)|Median Sep. (as) A Adaptive Optics 24461 3.152 1.182 C CCD (long focus) 117739 21.018 8.908 D Heliometer 1732 31.211 10.525 E Wide-field CCD 569837 46.125 14.640 H Space-based technique 646383 41.064 8.738 I Interferometry 907 0.273 0.164 J Visual Interferometer 4181 0.213 0.128 K Long-Baseline Interferometer 5252 0.426 0.047 M Micrometer 425462 10.257 2.140 O Occultation 2453 0.577 0.100 P Photography 186317 33.088 13.350 S Speckle Interferometer 143208 1.225 0.459 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 2400 76.975 13.900