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Pleiades, in astronomy

(Encyclopedia)Pleiades plēˈədēz, plīˈ– [key], in astronomy, famous open star cluster in the constellation Taurus; cataloged as M45. The cluster consists of some 500 stars, has a diameter of 35 light-years, ...

plum, in botany

(Encyclopedia)plum, common name for a tree of any of many species of the genus Prunus of the family Rosaceae (rose family) and for its fruit, a drupe. The plum is generally cultivated in the temperate zones, though...

Pluto, in astronomy

(Encyclopedia)Pluto, in astronomy, a dwarf planet and the first Kuiper belt, or transneptunian, object (see comet) to be discovered (1930) by astronomers. Pluto has an elliptical orbit usually lying beyond that of ...

pod, in aviation

(Encyclopedia)pod, in aviation: see airplane.

pod, in botany

(Encyclopedia)pod or legume, dehiscent fruit of a member of the family Leguminosae (pulse family). At maturity the pod splits along its two seams and releases the enclosed seeds. ...

power, in mathematics

(Encyclopedia)power, in mathematics: see exponent. ...

power, in physics

(Encyclopedia)power, in physics, time rate of doing work or of producing or expending energy. The unit of power based on the English units of measurement is the horsepower, devised for describing mechanical power b...

phase, in astronomy

(Encyclopedia)CE5 Phases of the moon phase, in astronomy, the measure of how much of the illuminated surface of a planet or satellite can be seen from a point at a distance from that body; the term is most ofte...

phase, in physics

(Encyclopedia)phase, in physics: see wave.

Phoebe, in astronomy

(Encyclopedia)Phoebe fēˈbē [key], in astronomy, one of the named moons, or natural satellites, of Saturn. Also known as Saturn IX (or S9), Phoebe is 137 mi (220 km) in diameter, orbits Saturn at a mean distance ...