Who discovered the first Apollo asteroid called 1862 Apollo?

Karl Wilhelm Reinmuth (Heidelberg, Germany, 4 April 1892 – Heidelberg, Germany, 6 May 1979) was a German astronomer and a prolific discoverer of 395 minor planets.

From 1912 to 1957, he was working as an astronomer at the Heidelberg Observatory in southern Germany. He was a member of the minor planet studies group at Astronomisches Rechen-Institut, and later became in chief-observer at Heidelberg Observatory until his retirement in 1957. He obtained more than 12,500 precise astrometric measurements of minor planets' positions on photographic plates, an enormous accomplishment before computer-based assistance existed.

In 1932 he discovered an asteroid, approximately 1.5 kilometers in diameter, but was lost shortly thereafter and not rediscovered until 1973. It was called 1862 Apollo, and it's the namesake and the first recognized member of the Apollo asteroids, a subgroup of near-Earth objects (NEO) which are Earth-crossers, that is, they cross the orbit of the Earth when viewed perpendicularly to the ecliptic plane (crossing an orbit is a more general term than actually intersecting it).

Its Orbital Period, that is the time it takes to complete an orbit of the Sun is 1.81 years. Its takes 3.065 Hours to do a full rotation period. A close approach will occur in 2046 when it will get to within 0.0353 AU (Astronomical unit: is a unit of length, roughly the distance from Earth to the Sun and approximately equal to 93 million miles or 150 million kilometres).