Delta Herculis (δ Herculis, abbreviated Delta Her, δ Her) is a
multiple star system
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 speaki ...
in the
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 ...
of
Hercules
Hercules (, ) is the Roman equivalent of the Greek divine hero Heracles, son of Jupiter and the mortal Alcmena. In classical mythology, Hercules is famous for his strength and for his numerous far-ranging adventures.
The Romans adapted the Gr ...
. Its light produces to us
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 li ...
3.12, as such the third-brightest star in the large, fairly dim constellation. Based on
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 ...
measurement taken during the
Hipparcos
''Hipparcos'' was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial obj ...
It consists of a binary pair, designated Delta Herculis A, together with three potential companions, suffixed B, C and D. Furthermore B is believed to be an
optical binary
In observational astronomy, a double star or visual double is a pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes.
This occurs because the pair either forms a binary star (i.e. a bi ...
. A's components are designated Delta Herculis Aa (officially named Sarin , the traditional name of the system) and Ab.
The angular separation between the main component A and the component B, which has a magnitude of 8.74, is 8.5 arcsecond
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. ...
. The designations of the four constituents as ''Delta Herculis A'', ''B'', ''C'' and ''D'', and those of ''A's'' components - ''Delta Herculis Aa'' and ''Ab'' - derive from the convention used by the Washington Multiplicity Catalog (WMC) for
multiple star system
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 speaki ...
s, and adopted by the
International Astronomical Union
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...
(IAU).
It bore the traditional name ''Sarin''. In 2016, the
International Astronomical Union
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...
organized a
Working Group on Star Names
The International Astronomical Union (IAU) established a Working Group on Star Names (WGSN) in May 2016 to catalog and standardize proper names for stars for the international astronomical community. It operates under Division C – Education ...
(WGSN) to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems. It approved the name ''Sarin'' for the component Delta Herculis Aa on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.
In the catalogue of stars in the ''Calendarium'' of Al Achsasi al Mouakket, this star was designated ''Menkib al Jathi al Aisr'', which was translated into
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
as ''Humerus Sinister Ingeniculi'', meaning ''kneeler's left shoulder''.
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 '' Left Wall of Heavenly Market Enclosure'', refers to an asterism which represents eleven old states in China which is marking the left borderline of the enclosure, consisting of Delta Herculis,
Lambda Herculis
Lambda Herculis (λ Herculis. abbreviated Lambda Her, λ Her), formally named Maasym , is a star in the constellation of Hercules. From parallax measurements taken during the Gaia mission, it is approximately 393 light-years from the Sun.
...
Omicron Herculis
Omicron Herculis, Latinized from o Herculis, is a star in the constellation Hercules. It used to be called Masym ("the wrist"), but this name was transferred to Lambda Herculis.
Properties
Omicron Herculis is a B9.5III star approxim ...
,
112 Herculis
112 Herculis is a binary star system in the northern constellation of Hercules. It is dimly visible to the naked eye with a combined apparent visual magnitude of 5.43. The secondary component is about two magnitudes fainter than the prim ...
Eta Serpentis
Eta Serpentis, Latinized from η Serpentis, is a star in the constellation Serpens. In particular, it lies in Serpens Cauda, the snake's tail. The star has an apparent visual magnitude of 3.260, making it visible to the naked eye. Parall ...
,
Nu Ophiuchi
Nu Ophiuchi (ν Oph, ν Ophiuchi) is a star in the equatorial constellation of Ophiuchus. The apparent visual magnitude is +3.3, making it one of the brighter members of this constellation. Based upon parallax measurements made during ...
,
Xi Serpentis
Xi Serpentis, Latinized from ξ Serpentis, is a triple star system in the Serpens Cauda (tail) section of the equatorial constellation Serpens. Based upon an annual parallax shift of 30.98 mas as seen from Earth, it is located 105 ...
and
Eta Ophiuchi
Eta Ophiuchi (η Ophiuchi, abbreviated Eta Oph, η Oph) is a binary star in the constellation of Ophiuchus. Based on stellar parallax, parallax measurements taken during the Hipparcos mission, it is approximately 88 light-years from the ...
. Consequently, the Chinese name for Delta Herculis itself is (, en, the First Star of Left Wall of Heavenly Market Enclosure), and represents the state of
Wei
Wei or WEI may refer to:
States
* Wey (state) (衛, 1040–209 BC), Wei in pinyin, but spelled Wey to distinguish from the bigger Wei of the Warring States
* Wei (state) (魏, 403–225 BC), one of the seven major states of the Warring States per ...
(魏), together with
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 ...
, according to Ian Ridpath version or
Phi Capricorni
Phi Capricorni (φ Cap, φ Capricorni) is a solitary star in the southern constellation of Capricornus. It is visible to the naked eye with an apparent visual magnitude of +5.16. Based upon an annual parallax shift of 5.07 milliarcse ...
and
Chi Capricorni
Chi Capricorni, Latinized from χ Capricorni, is a star in the southern constellation of Capricornus. Based upon an annual parallax shift of 18.14 mas as seen from the Earth, the star is located about 180 light years from th ...
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 Hert ...
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 A3IV. It has both a mass and radius that are roughly two times solar yielding a total
luminosity
Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object over time. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a st ...
of about
See also
*
Lists of stars
The following are lists of stars. These are astronomical objects that spend some portion of their existence generating energy through thermonuclear fusion.
By location
* Lists of stars by constellation
By name
* List of traditional star names
* L ...
in the constellation
Hercules
Hercules (, ) is the Roman equivalent of the Greek divine hero Heracles, son of Jupiter and the mortal Alcmena. In classical mythology, Hercules is famous for his strength and for his numerous far-ranging adventures.
The Romans adapted the Gr ...