LZ Cephei, also known by its

Flamsteed designation A Flamsteed designation is a combination of a number and constellation name that uniquely identifies most naked eye stars in the 88 modern constellations, modern constellations visible from southern England. They are named after John Flamsteed, au ...

14 Cephei, is a star about 3,600

light year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distance, astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by t ...

s from the Earth, in the constellation Cepheus. Its

apparent magnitude Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), ...

is 5.6, making it faintly visible to the

naked eye Naked eye, also called bare eye or unaided eye, is the practice of engaging in visual perception unaided by a magnification, magnifying, Optical telescope#Light-gathering power, light-collecting optical instrument, such as a telescope or microsc ...

of an observer far from

city lights ''City Lights'' is a 1931 American synchronized sound film, sound romance film, romantic comedy drama, comedy-drama film written, produced, directed by, and starring Charlie Chaplin. While the film has no audible dialog, it was released with a ...

. The star is a rotating ellipsoidal variable whose brightness, as measured by the ''

Hipparcos ''Hipparcos'' was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions and distances of ...

'' satellite, varies between magnitude 5.52 and 5.61. LZ Cephei was discovered to be a binary star by

William Edmund Harper William Edmund Harper, March 20, 1878 – June 14, 1940, (age 62) was a Canadian astronomer. William Harper was born in Dobbington, Ontario. He attended high school in Owen Sound, then taught for three years following his graduation. When he had ...

in 1931. The

orbital elements Orbital elements are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are considered in two-body systems using a Kepler orbit. There are many different ways to mathematically describe the same o ...

were first calculated by Robert Methven Petrie in 1962. It was discovered to be a variable star in 1972 by N. Kameswara Rao, using the

Lick Observatory The Lick Observatory is an astronomical observatory owned and operated by the University of California. It is on the summit of Mount Hamilton (California), Mount Hamilton, in the Diablo Range just east of San Jose, California, United States. The ...

's 24 inch telescope. The star was given the

variable star designation In astronomy, a variable-star designation is a unique identifier given to variable stars. It extends the Bayer designation format, with an identifying label (as described below) preceding the Latin genitive of the name of the constellation in whic ...

LZ Cephei in 1973. It was classified as an ellipsoidal variable by Hill ''et al.'' in 1976. A 2011 study of LZ Cephei concluded that the existing data are best explained if the system is a semi-detached binary with either the primary or secondary star nearly filling its

Roche lobe In astronomy, the Roche lobe is the region around a star in a binary system within which orbiting material is gravitationally bound to that star. It is an approximately teardrop-shaped region bounded by a critical gravitational equipotential, ...

. The secondary star, now less massive than the primary, was originally the more massive star, and matter has been transferred from the secondary to the primary.

References

{{DEFAULTSORT:LZ Cephei Rotating ellipsoidal variables Cepheus (constellation) 108772 209481 Durchmusterung objects Cephei, LZ Cephei, 14 8406