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 of Andromeda. The system is visible to the naked eye as a point of light with a combined
apparent visual magnitude
Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's lig ...
of 3.28. Based upon parallax measurements, it is located at a distance of approximately from the
Sun
The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...
. The system is drifting closer with a radial velocity 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 ...
, (), 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,
65 Piscium 65 may refer to:
* 65 (number)
* ''65'' (film), an upcoming American science fiction thriller film
* One of the years 65 BC, AD 65, 1965, 2065
* A type of dish in Indian cuisine, such as Chicken 65
Chicken 65 is a spicy, deep-fried chicken dish ...
Chinese name
Chinese names or Chinese personal names are names used by individuals from Greater China and other parts of the Chinese-speaking world throughout East and Southeast Asia (ESEA). In addition, many names used in Japan, Korea and Vietnam are ofte ...
star atlas
Celestial cartography, uranography,
astrography or star cartography is the aspect of astronomy and branch of cartography concerned with mapping stars, galaxies, and other astronomical objects on the celestial sphere. Measuring the position ...
.
This is a long-period spectroscopic binary with an orbital period of approximately 15,000 days (41 years). The primary of the spectroscopic binary, component Aa, has a stellar classification of K3 III, indicating that it is an aging
giant star
A giant star is a star with substantially larger radius and luminosity than a main-sequence (or ''dwarf'') star of the same surface temperature.Giant star, entry in ''Astronomy Encyclopedia'', ed. Patrick Moore, New York: Oxford University Press ...
. It most likely evolved from a F-type main sequence 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
A coronagraph is a telescopic attachment designed to block out the direct light from a star so that nearby objects – which otherwise would be hidden in the star's bright glare – can be resolved. Most coronagraphs are intended to view t ...
. The pair have a physical separation of . The system has two companions, the closest of which is most likely an orbiting red dwarf 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 ...
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
A debris disk (American English), or debris disc (Commonwealth English), is a circumstellar disk of dust and debris in orbit around a star. Sometimes these disks contain prominent rings, as seen in the image of Fomalhaut on the right. Debris di ...