22P/Kopff

Comet Kopff or 22P/Kopff is a periodic comet in the Solar System. Discovered on August 23, 1906, it was named after August Kopff who discovered the comet. The comet was missed on its November 1912 return, but was recovered on its June 1919 return. The comet has not been missed since its 1919 return and its last perihelion passage was on May 25, 2009. Close approaches to Jupiter in 1938 and 1943 decreased the perihelion distance and orbital period. 22P/Kopff’s next perihelion passage is October 25, 2015.

Observations

1631 Kopff

1631 Kopff, provisional designation 1936 UC, is a stony asteroid from the inner regions of the asteroid belt, about 9 kilometers in diameter. It was discovered by Finnish astronomer Yrjö Väisälä at Turku Observatory on 11 October 1936 (also see discovery circumstances below).

The asteroid is a member of the Flora family, a large group of stony S-type asteroids in the inner main-belt. It orbits the Sun at a distance of 1.8–2.7 AU once every 3 years and 4 months (1,221 days). Its orbit shows an eccentricity of 0.21 and is tilted by 7 degrees to the plane of the ecliptic. It has a rotation period of 6.7 hours and an albedo of 0.250, according to the surveys carried out by IRAS, Akari, and WISE/NEOWISE.

The minor planet was named after German astronomer August Kopff (1882–1960). He was first an assistant to Max Wolf prolific discoverer of minor planets himself. In 1924 he became Director of the Astronomisches Rechen-Institut in Berlin, and after the western section moved to Heidelberg he also became director of Heidelberg-Königstuhl Observatory. He was responsible for constructing the third Catalogue of Fundamental Stars (FK3) and initiated work on the fourth (FK4). The lunar carter Kopff is also named in his honour.

Kopff (crater)

Kopff is a lunar crater that lies along the eastern edge of the inner Mare Orientale impact basin, on the western limb of the Moon. In this position the crater is seen from on edge from the Earth, and its visibility is affected by libration. This situation makes it difficult to discern much detail about the crater unless it is viewed from orbit.

At one time this crater was considered to have formed due to volcanic activity, in contrast to most lunar craters which are considered to have been created through impacts. However it is more likely that the crater was formed by an impact against a surface that was still partly molten. This has left the crater with a sharp-edged, circular rim and a flat, dark-hued interior floor. Indeed, the albedo of the interior floor matches that of the lunar mare to the west. The southeast part of the floor is fractured with a series of narrow rilles. The floor along the northwest and northeast edges is more rugged, and these sections have escaped the lava that covered the remainder of the floor.