Phi Andromedae
Encyclopedia
Phi Andromedae (φ Andromedae, φ And) is a binary star system near the border of the constellation
of Andromeda
, approximately 720 light years from the Earth
. With χ And
it forms the Chinese asterism
軍南門 (Keun Nan Mun, Mandarin
jūnnánmén), "the South Gate of the Camp".
subgiant with an apparent magnitude
of 4.6m. The companion star, φ And B, is a blue-white B-type main sequence dwarf
with an apparent magnitude of 5.6m. The two stars are separated by 0.64 arcseconds and have an orbital period of 371.6 years. The combined brightness of the system is 4.26m.
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
of Andromeda
Andromeda (constellation)
Andromeda is a constellation in the northern sky. It is named after Andromeda, the princess in the Greek legend of Perseus who was chained to a rock to be eaten by the sea monster Cetus...
, approximately 720 light years from the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
. With χ And
Chi Andromedae
Chi Andromedae is a star in the constellation Andromeda. It with φ And composed Chinese asterism 軍南門 , "the South Gate of the Camp"....
it forms the Chinese asterism
Asterism (astronomy)
In astronomy, an asterism is a pattern of stars recognized on Earth's night sky. It may form part of an official constellation, or be composed of stars from more than one. Like constellations, asterisms are in most cases composed of stars which, while they are visible in the same general direction,...
軍南門 (Keun Nan Mun, Mandarin
Standard Mandarin
Standard Chinese or Modern Standard Chinese, also known as Mandarin or Putonghua, is the official language of the People's Republic of China and Republic of China , and is one of the four official languages of Singapore....
jūnnánmén), "the South Gate of the Camp".
Double star
The primary component, φ And A, is a blue-white B-typeStellar classification
In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...
subgiant with an apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
of 4.6m. The companion star, φ And B, is a blue-white B-type main sequence dwarf
Main sequence
The main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell...
with an apparent magnitude of 5.6m. The two stars are separated by 0.64 arcseconds and have an orbital period of 371.6 years. The combined brightness of the system is 4.26m.