▁merchant ▁and ▁supp orter ▁of ▁D issent ers ▁William ▁Cow ard ▁( p ir ate ) ▁( ), ▁minor ▁English ▁pir ate ▁ ▁See ▁also ▁Cow art <0x0A> </s> ▁ 1 7 5 7 ▁Por vo o , ▁prov is ional ▁design ation ▁, ▁is ▁a ▁pres umably ▁st ony ▁astero id ▁from ▁the ▁inner ▁regions ▁of ▁the ▁astero id ▁bel t , ▁approximately ▁ 1 0 ▁kilom eters ▁in ▁diameter . ▁It ▁was ▁discovered ▁on ▁ 1 7 ▁March ▁ 1 9 3 9 , ▁by ▁Finn ish ▁astronom er ▁Y r jö ▁V ä is äl ä ▁at ▁Tur ku ▁Observ atory ▁on ▁the ▁coast ▁of ▁south western ▁Finland . ▁The ▁astero id ▁was ▁named ▁for ▁the ▁Finn ish ▁city ▁of ▁Por vo o . ▁ ▁Or bit ▁and ▁classification ▁▁ ▁Por vo o ▁or bits ▁the ▁Sun ▁in ▁the ▁inner ▁main - b elt ▁at ▁a ▁distance ▁of ▁ 2 . 1 – 2 . 6   AU ▁once ▁every ▁ 3 ▁years ▁and ▁ 7 ▁months ▁( 1 , 3 1 7 ▁days ). ▁Its ▁orbit ▁has ▁an ▁ecc ent ric ity ▁of ▁ 0 . 1 3 ▁and ▁an ▁incl ination ▁of ▁ 4 ° ▁with ▁respect ▁to ▁the ▁e cli ptic . ▁As ▁no ▁prec over ies ▁were ▁taken , ▁and ▁no ▁prior ▁ident ifications ▁were ▁made , ▁Por vo os ▁observation ▁arc ▁begins ▁with ▁its ▁official ▁discovery ▁observation . ▁ ▁Phys ical ▁characteristics ▁ ▁Rot ation ▁period ▁▁ ▁In ▁the ▁early ▁ 1 9 8 0