binary star
A binary star is a system of two stars that are 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 separate stars, in ...
system in the southern
constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The origins of the earliest constellation ...
of
Capricornus
Capricornus is one of the constellations of the zodiac. Its name is Latin for "horned goat" or "goat horn" or "having horns like a goat's", and it is commonly represented in the form of a sea goat: a mythical creature that is half goat, half f ...
. It can be seen with the naked eye, having 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 +4.84. Based upon an annual
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 object ...
shift of 20.20 mas as seen from the Earth, the star is located about 161
light year
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...
s 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 pair orbit each other with a
period
Period may refer to:
Common uses
* Era, a length or span of time
* Full stop (or period), a punctuation mark
Arts, entertainment, and media
* Period (music), a concept in musical composition
* Periodic sentence (or rhetorical period), a concept ...
of 27.85 years, a
semimajor axis
In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the lo ...
of 0.265
arc second
A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The n ...
s, an
eccentricity
Eccentricity or eccentric may refer to:
* Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal"
Mathematics, science and technology Mathematics
* Off-Centre (geometry), center, in geometry
* Eccentricity (g ...
of 0.410. The primary member, component A, is a white-hued
A-type main sequence star
An A-type main-sequence star (A V) or A dwarf star is a main-sequence (hydrogen-burning) star of spectral type A and luminosity class V (five). These stars have spectra defined by strong hydrogen Balmer absorption lines. They measure between 1 ...
with an
apparent 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 ...
of +5.02. Its companion, component B, has an apparent magnitude of +7.39.
Nomenclature
''η Capricorni'' ( Latinised to ''Eta Capricorni'') is the system's
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 ...
. It also has the
Flamsteed designation
A Flamsteed designation is a combination of a number and constellation name that uniquely identifies most naked eye stars in the modern constellations visible from southern England. They are named for John Flamsteed who first used them while co ...
22 Capricorni.
In Chinese, (), meaning '' Twelve States'', refers to an asterism which is represent twelve ancient states in the
Spring and Autumn period
The Spring and Autumn period was a period in Chinese history from approximately 770 to 476 BC (or according to some authorities until 403 BC) which corresponds roughly to the first half of the Eastern Zhou period. The period's name derives fr ...
and the
Warring States period
The Warring States period () was an era in History of China#Ancient China, ancient Chinese history characterized by warfare, as well as bureaucratic and military reforms and consolidation. It followed the Spring and Autumn period and concluded ...
35 Capricorni
This is the list of notable stars in the constellation Capricornus, sorted by decreasing brightness.
See also
* List of stars by constellation
References
*
*
*
*
*
*
*
{{Stars of Capricornus
*List
Capricornus
Capricornus is one of th ...
30 Capricorni
This is the list of notable stars in the constellation Capricornus, sorted by decreasing brightness.
See also
* List of stars by constellation
References
*
*
*
*
*
*
*
{{Stars of Capricornus
*List
Capricornus
Capricornus is one of th ...
,
33 Capricorni
33 may refer to:
*33 (number)
*33 BC
*AD 33
*1933
*2033
Music
* ''33'' (Luis Miguel album) (2003)
* ''33'' (Southpacific album) (1998)
* ''33'' (Wanessa album) (2016)
*"33 'GOD'", a 2016 song by Bon Iver
* "Thirty-Three" (song), a 1995 song by th ...
19 Capricorni
Nineteen or 19 may refer to:
* 19 (number), the natural number following 18 and preceding 20
* one of the years 19 BC, AD 19, 1919, 2019
Films
* ''19'' (film), a 2001 Japanese film
* ''Nineteen'' (film), a 1987 science fiction film
Music ...
,
26 Capricorni
6 (six) is the natural number following 5 and preceding 7. It is a composite number and the smallest perfect number.
In mathematics
Six is the smallest positive integer which is neither a square number nor a prime number; it is the second ...
,
27 Capricorni
This is the list of notable stars in the constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived pattern or outline, typically representing an animal, mythological subject, or ina ...
21 Capricorni
1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length 1. I ...
. Consequently, the
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 ...
for η Capricorni itself is (, en, the First Star of Zhou), meaning that this star (together with
21 Capricorni
1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length 1. I ...
and β Serpentis in '' Right Wall of Heavenly Market Enclosure'' (asterism)) represent ''Zhou'' () (possibly Chow, the dynasty in China).
Sometimes, this star is called by the name ''Armus'' in an astrological context.