What binary F-type main-sequence star has the slowest stellar rotational velocity ?
select ?ent where { ?ent wdt:P31 wd:Q1353952 . ?ent wdt:P4296 ?obj . ?ent wdt:P31 wd:Q50053. } ORDER BY ASC(?obj)LIMIT 5 
f-type main-sequence star: Q1353952 binary star: Q50053