History

The planetary nebula Abell 41 was discovered in 1955 by the American astronomer George Ogden Abell on the photo plates of the Palomar Observatory Sky Survey (POSS). In 1955 he published a first list of 13 globular clusters and the positions of 73 planetary nebulae. The PN was then listed as number 29 (A55 29). In 1966 Abell published a completed list including the size and description of the 86 planetary nebulae discovered on the POSS photo plates. The PN was then listed as nebula 41 (A66 41). He described it with «E» as «a ring with gaps (incomplete ring)» ^{[331, 332]}

The designation PK 9+10.1 originates from the two Czechoslovak astronomers Luboš Perek and Luboš Kohoutek, who in 1967 compiled a catalog of all the planetary nebulae of the Milky Way known at the time. ^[146]

Physical Properties

Abell 41 is a planetary nebula with a waisted, bipolar structure and an expansion velocity of ~40 km/s at the waist. Its central star is MT Ser, a close-binary system, consisting of two evolved, hot subdwarfs with a period of 5h 26m. ^[31] The heliocentric distance of the nebula is ~4.6 kpc. Magnitudes through different filters: B 16.06; V 15.95; J 15.69; H 15.806; K 15.162. ^[145]