Delta Ophiuchi
Encyclopedia
Delta Ophiuchi is a star
in the constellation
Ophiuchus
. It has the traditional name Yed Prior (and the star Epsilon Ophiuchi
, with which it forms a naked eye
optical double
, is Yed Posterior).
The traditional name Yed is derived from Arabic
meaning "the hand", and the two stars are the left hand of Ophiuchus (the Serpent Bearer) that holds the head of the serpent Serpens Caput.
It was a member of the indigenous Arabic asterism
al-Nasaq al-Yamānī, "the Southern Line" of al-Nasaqān "the Two Lines". It was a member of indigenous Arabic asterism
al-Nasaq al-Yamānī, "the Southern Line" of al-Nasaqān "the Two Lines"., along with α Ser
(Unukalhai), δ Ser
(Qin, Tsin), ε Ser
(Ba, Pa), ε Oph
(Yed Posterior), ζ Oph
(Han) and γ Oph
(Tsung Ching).
According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, al-Nasaq al-Yamānī or Nasak Yamani were the title for two stars :δ Ser
as Nasak Yamani I and ε Ser
as Nasak Yamani II (exclude this star, α Ser
, ε Oph
, ζ Oph
and γ Oph
)
In Chinese
, , meaning Right Wall of Heavenly Market Enclosure
, refers to an asterism which is represent eleven old states in China which is marking the right borderline of the enclosure, consisting of δ Ophiuchi, β Herculis
, γ Herculis
, κ Herculis
, γ Serpentis, β Serpentis
, α Serpentis
, δ Serpentis
, ε Serpentis
, ε Ophiuchi
and ζ Ophiuchi
. Consequently, δ Ophiuchi itself is known as , represent the state Liang
(梁) (or Leang).
, while Epsilon is 108; hence they are a mere optical double. Yed Prior is a red giant
(class M) with a temperature of 3,679 K
.
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....
Ophiuchus
Ophiuchus
Ophiuchus is a large constellation located around the celestial equator. Its name is from the Greek "serpent-bearer", and it is commonly represented as a man grasping the snake that is represented by the constellation Serpens. Ophiuchus was one of the 48 constellations listed by the 2nd-century...
. It has the traditional name Yed Prior (and the star Epsilon Ophiuchi
Epsilon Ophiuchi
Epsilon Ophiuchi is a star in the constellation Ophiuchus. It has the traditional name Yed Posterior ....
, with which it forms a naked eye
Naked eye
The naked eye is a figure of speech referring to human visual perception unaided by a magnifying or light-collecting optical device, such as a telescope or microscope. Vision corrected to normal acuity using corrective lenses is considered "naked"...
optical double
Double star
In observational astronomy, a double star is a pair of stars that appear close to each other in the sky as seen from Earth when viewed through an optical telescope. This can happen either because the pair forms a binary star, i.e...
, is Yed Posterior).
The traditional name Yed is derived from Arabic
Arabic language
Arabic is a name applied to the descendants of the Classical Arabic language of the 6th century AD, used most prominently in the Quran, the Islamic Holy Book...
meaning "the hand", and the two stars are the left hand of Ophiuchus (the Serpent Bearer) that holds the head of the serpent Serpens Caput.
It was a member of the indigenous Arabic asterism
Asterism (astronomy)
In astronomy, an asterism is a pattern of stars recognized on Earth's night sky. It may form part of an official constellation, or be composed of stars from more than one. Like constellations, asterisms are in most cases composed of stars which, while they are visible in the same general direction,...
al-Nasaq al-Yamānī, "the Southern Line" of al-Nasaqān "the Two Lines". It was a member of indigenous Arabic asterism
Asterism (astronomy)
In astronomy, an asterism is a pattern of stars recognized on Earth's night sky. It may form part of an official constellation, or be composed of stars from more than one. Like constellations, asterisms are in most cases composed of stars which, while they are visible in the same general direction,...
al-Nasaq al-Yamānī, "the Southern Line" of al-Nasaqān "the Two Lines"., along with α Ser
Alpha Serpentis
Alpha Serpentis is a triple star system in the constellation Serpens, in its head . Alpha Serpentis has the proper names Unukalhai, from the Arabic عنق الحية ‘Unuq al-Ħayyah "the Serpent's Neck", and Cor Serpentis from the Latin "the Heart of the Serpent"...
(Unukalhai), δ Ser
Delta Serpentis
Delta Serpentis is a star system in the constellation Serpens, in its head . It was a member of indigenous Arabic asterism al-Nasaq al-Yamānī, "the Southern Line" of al-Nasaqān "the Two Lines"., along with α Ser , ε Ser , δ Oph , ε Oph , ζ Oph and γ Oph .According to the...
(Qin, Tsin), ε Ser
Epsilon Serpentis
Epsilon Serpentis is a star in the constellation Serpens, in its head .It was a member of indigenous Arabic asterism al-Nasaq al-Yamānī, "the Southern Line" of al-Nasaqān "the Two Lines"., along with α Ser , δ Ser , δ Oph , ε Oph , ζ Oph and γ Oph .According to the...
(Ba, Pa), ε Oph
Epsilon Ophiuchi
Epsilon Ophiuchi is a star in the constellation Ophiuchus. It has the traditional name Yed Posterior ....
(Yed Posterior), ζ Oph
Zeta Ophiuchi
Zeta Ophiuchi is a star located in the constellation of Ophiuchus. It was a member of indigenous Arabic asterism al-Nasaq al-Yamānī, "the Southern Line" of al-Nasaqān "the Two Lines"., along with α Ser , δ Ser , ε Ser , δ Oph , ε Ser and γ Oph .According to the catalogue of stars...
(Han) and γ Oph
Gamma Ophiuchi
Gamma Ophiuchi is a Class A4, fourth-magnitude star in the constellation Ophiuchus. Gamma Ophiuchi is a stellar system located about 95 light-years from Earth....
(Tsung Ching).
According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, al-Nasaq al-Yamānī or Nasak Yamani were the title for two stars :δ Ser
Delta Serpentis
Delta Serpentis is a star system in the constellation Serpens, in its head . It was a member of indigenous Arabic asterism al-Nasaq al-Yamānī, "the Southern Line" of al-Nasaqān "the Two Lines"., along with α Ser , ε Ser , δ Oph , ε Oph , ζ Oph and γ Oph .According to the...
as Nasak Yamani I and ε Ser
Epsilon Serpentis
Epsilon Serpentis is a star in the constellation Serpens, in its head .It was a member of indigenous Arabic asterism al-Nasaq al-Yamānī, "the Southern Line" of al-Nasaqān "the Two Lines"., along with α Ser , δ Ser , δ Oph , ε Oph , ζ Oph and γ Oph .According to the...
as Nasak Yamani II (exclude this star, α Ser
Alpha Serpentis
Alpha Serpentis is a triple star system in the constellation Serpens, in its head . Alpha Serpentis has the proper names Unukalhai, from the Arabic عنق الحية ‘Unuq al-Ħayyah "the Serpent's Neck", and Cor Serpentis from the Latin "the Heart of the Serpent"...
, ε Oph
Epsilon Ophiuchi
Epsilon Ophiuchi is a star in the constellation Ophiuchus. It has the traditional name Yed Posterior ....
, ζ Oph
Zeta Ophiuchi
Zeta Ophiuchi is a star located in the constellation of Ophiuchus. It was a member of indigenous Arabic asterism al-Nasaq al-Yamānī, "the Southern Line" of al-Nasaqān "the Two Lines"., along with α Ser , δ Ser , ε Ser , δ Oph , ε Ser and γ Oph .According to the catalogue of stars...
and γ Oph
Gamma Ophiuchi
Gamma Ophiuchi is a Class A4, fourth-magnitude star in the constellation Ophiuchus. Gamma Ophiuchi is a stellar system located about 95 light-years from Earth....
)
In Chinese
Chinese language
The Chinese language is a language or language family consisting of varieties which are mutually intelligible to varying degrees. Originally the indigenous languages spoken by the Han Chinese in China, it forms one of the branches of Sino-Tibetan family of languages...
, , meaning Right Wall of Heavenly Market Enclosure
Heavenly Market enclosure
Tian Shi Yuan, the Heavenly Market Enclosure , is one of the San Yuan or Three enclosures. Stars and constellations of this group are visible during late summer and early autumn in the Northern Hemisphere . The summer triangle lies directly to the northwest.-Asterisms:The asterisms are :...
, refers to an asterism which is represent eleven old states in China which is marking the right borderline of the enclosure, consisting of δ Ophiuchi, β Herculis
Beta Herculis
Beta Herculis , which also has the name Kornephoros, is the brightest star in the constellation of Hercules. It has an apparent visual magnitude which varies between 2.76 and 2.81.Although β Herculis appears to the naked eye to be a single star, W. W...
, γ Herculis
Gamma Herculis
Gamma Herculis is a magnitude 3.74 binary star in the constellation Hercules. It is a giant star with a stellar classification of A9III that is located at a distance of about 195 light years from the Earth.-Name:...
, κ Herculis
Kappa Herculis
Kappa Herculis is a double star in the constellation Hercules. Traditional names that have been attributed to the star are "Marfik", "Marfak" or "Marsic", all of which come from the Arabic لمرفق Al-Mirfaq meaning "the elbow", a name it shares with Lambda Ophiuchi.- Properties :Kappa Herculis is a...
, γ Serpentis, β Serpentis
Beta Serpentis
Beta Serpentis is a star system in the constellation Serpens, in its head . It was a member of indigenous Arabic asterism al-Nasaq al-Sha'āmī, "the Northern Line" of al-Nasaqān "the Two Lines", along with β Her , γ Her and γ Ser .According to the catalogue of stars in the Technical Memorandum...
, α Serpentis
Alpha Serpentis
Alpha Serpentis is a triple star system in the constellation Serpens, in its head . Alpha Serpentis has the proper names Unukalhai, from the Arabic عنق الحية ‘Unuq al-Ħayyah "the Serpent's Neck", and Cor Serpentis from the Latin "the Heart of the Serpent"...
, δ Serpentis
Delta Serpentis
Delta Serpentis is a star system in the constellation Serpens, in its head . It was a member of indigenous Arabic asterism al-Nasaq al-Yamānī, "the Southern Line" of al-Nasaqān "the Two Lines"., along with α Ser , ε Ser , δ Oph , ε Oph , ζ Oph and γ Oph .According to the...
, ε Serpentis
Epsilon Serpentis
Epsilon Serpentis is a star in the constellation Serpens, in its head .It was a member of indigenous Arabic asterism al-Nasaq al-Yamānī, "the Southern Line" of al-Nasaqān "the Two Lines"., along with α Ser , δ Ser , δ Oph , ε Oph , ζ Oph and γ Oph .According to the...
, ε Ophiuchi
Epsilon Ophiuchi
Epsilon Ophiuchi is a star in the constellation Ophiuchus. It has the traditional name Yed Posterior ....
and ζ Ophiuchi
Zeta Ophiuchi
Zeta Ophiuchi is a star located in the constellation of Ophiuchus. It was a member of indigenous Arabic asterism al-Nasaq al-Yamānī, "the Southern Line" of al-Nasaqān "the Two Lines"., along with α Ser , δ Ser , ε Ser , δ Oph , ε Ser and γ Oph .According to the catalogue of stars...
. Consequently, δ Ophiuchi itself is known as , represent the state Liang
Liang (state)
The State of Liang was one of the states during the Spring and Autumn Period , bordering the State of Qin and was conquered by Duke Mu of Qin in 641 BCE. The rulers of the State of Liang has the surname Ying , similar to the neighboring State of Qin...
(梁) (or Leang).
Structure
Delta Ophiuchi is 170 light years from EarthEarth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
, while Epsilon is 108; hence they are a mere optical double. Yed Prior is a red giant
Red giant
A red giant is a luminous giant star of low or intermediate mass in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius immense and the surface temperature low, somewhere from 5,000 K and lower...
(class M) with a temperature of 3,679 K
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
.