Delta Andromedae, Latinized from δ Andromedae, is a
triple star
A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. A large group of stars bound by gravitation is generally called a '' star cluster'' or '' galaxy'', although, broadly speak ...
system in the northern
constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The origins of the e ...
parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...
measurements, it is located at a distance of approximately from the Sun. The system is drifting closer with a
radial velocity
The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the temporal rate of change, rate of change of the distance or Slant range, range between the two points. It is e ...
of −10 km/s.
In
Chinese
Chinese can refer to:
* Something related to China
* Chinese people, people of Chinese nationality, citizenship, and/or ethnicity
**''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation
** List of ethnic groups in China, people of va ...
, (), meaning ''
Legs
A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element ...
(asterism)'', refers to an asterism consisting of δ Andromedae,
η Andromedae
Eta Andromedae (Eta And, η Andromedae, η And) is a spectroscopic binary star in the constellation of Andromeda. It consists of two G-type subgiant or giant stars orbiting each other with a period of 115.7 days an ...
Ï€ Andromedae
Pi Andromedae (Pi And, π Andromedae, π And) is the Bayer designation for a binary star system in the northern constellation of Andromeda. With an apparent visual magnitude of 4.4, it is visible to the naked eye. It i ...
,
ν Andromedae
Nu Andromedae (Nu And, ν Andromedae, ν And) is a binary star in the constellation Andromeda. The system has an apparent visual magnitude of 4.5, which is bright enough to be seen with the naked eye. It is approximately ...
,
μ Andromedae
Mu Andromedae (Mu And, μ Andromedae, μ And) is the Bayer designation for a star in the northern constellation of Andromeda. It has an apparent visual magnitude of 3.87, making it readily visible to the naked eye. Based ...
σ Piscium
Sigma Piscium (Sigma Psc, σ Piscium, σ Psc) is a main-sequence star in the zodiac constellation of Pisces. It has an apparent magnitude of +5.50, meaning it is barely visible to the naked eye, according to the Bortle ...
91 Piscium
This is the list of notable stars in the constellation Pisces, sorted by decreasing brightness.
See also
*List of stars by constellation
References
*
*
*
*
*
{{Stars of Pisces
*List
Pisces
Pisces may refer to:
* Pisces, an obsolete (beca ...
φ Piscium
Phi Piscium, Latinized from φ Piscium, is a quadruple star system approximately 380 light years away in the constellation Pisces. It consists of Phi Piscium A, with a spectral type of K0III, and Phi Piscium B. Phi Piscium A posses ...
Bayer designation
A Bayer designation is a stellar designation in which a specific star is identified by a Greek or Latin letter followed by the genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1,564 stars. ...
spectroscopic binary
A binary star is a system of two star, stars that are gravity, gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separa ...
with an orbital period of approximately 15,000 days (41 years). The primary of the spectroscopic binary, component Aa, has a
stellar classification
In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...
of K3 III, indicating that it is an aging giant star. It most likely evolved from a F-type
main sequence
In astronomy, 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 Her ...
star after consuming the hydrogen at its core. The secondary, component Ab, is a relatively faint K-type dwarf, which has been imaged using a stellar coronagraph. The pair have a physical separation of . The system has two companions, the closest of which is most likely an orbiting
red dwarf
''Red Dwarf'' is a British science fiction comedy franchise created by Rob Grant and Doug Naylor, which primarily consists of a television sitcom that aired on BBC Two between 1988 and 1999, and on Dave since 2009, gaining a cult following. T ...
of class M3 with a separation of at least 900
astronomical unit
The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits t ...
s.
An excess of infrared emission from δ Andromedae suggested that it may be surrounded by a shell of dust. In 2003 it was determined that this is more likely a circumstellar debris disk.
European Southern Observatory
The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental organization, intergovernmental research organisation made up of 16 mem ...