Epsilon Andromedae
Encyclopedia
Epsilon Andromedae (Epsilon And, ε Andromedae, ε And) is a G-type giant
star
in the constellation
of Andromeda
. It has an apparent visual magnitude of approximately 4.37.
ε Andromedae is believed to be a red clump
star which is fusing
helium
in its core. Its orbit
in the Milky Way
is highly eccentric
, causing it to move rapidly relative to the Sun
and its neighboring stars.
Giant star
A giant star is a star with substantially larger radius and luminosity than a main sequence star of the same surface temperature. Typically, giant stars have radii between 10 and 100 solar radii and luminosities between 10 and 1,000 times that of the Sun. Stars still more luminous than giants are...
star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
in the constellation
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...
. It has an apparent visual magnitude of approximately 4.37.
ε Andromedae is believed to be a red clump
Red clump
The red clump is a feature in the Hertzsprung-Russell diagram of stars. The red clump is considered the metal-rich counterpart to the horizontal branch. Stars in this part of the Hertzsprung-Russell diagram are sometimes called clump giants...
star which is fusing
Nuclear fusion
Nuclear fusion is the process by which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. This is usually accompanied by the release or absorption of large quantities of energy...
helium
Helium
Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...
in its core. Its orbit
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
in the Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
is highly eccentric
Orbital eccentricity
The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...
, causing it to move rapidly relative to the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
and its neighboring stars.