Delta Draconis
Encyclopedia
Delta Draconis is a yellow star
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....

 Draco
Draco (constellation)
Draco is a constellation in the far northern sky. Its name is Latin for dragon. Draco is circumpolar for many observers in the northern hemisphere...

. It has the traditional names Aldib, Altais (the goat) and Nodus Secundus.

The title Altais was derived from Arabic Al Tāis, "the Goat", the association of this star, along with π Dra, ρ Dra and ε Dra
Epsilon Draconis
Epsilon Draconis is a fourth-magnitude star in the constellation Draco. It has the traditional name Tyl. This star along with Delta Draconis , Pi Draconis and Rho Draconis forms an asterism known as Al Tāis, meaning "the Goat".In Chinese astronomy, , meaning the Celestial Kitchen, refers to an...

 (Tyl)..

According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Al Tāis or Tais were the title for three stars :δ Dra as Altais, π Dra as Tais I and ρ Dra as Tais II (exclude ε Dra
Epsilon Draconis
Epsilon Draconis is a fourth-magnitude star in the constellation Draco. It has the traditional name Tyl. This star along with Delta Draconis , Pi Draconis and Rho Draconis forms an asterism known as Al Tāis, meaning "the Goat".In Chinese astronomy, , meaning the Celestial Kitchen, refers to an...

)

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 Celestial Kitchen
Purple Forbidden enclosure
The Purple Forbidden enclosure is one of the San Yuan or Three enclosures. Stars and constellations of this group lie near the north celestial pole and visible all year from temperate latitudes in the Northern Hemisphere.-Asterisms:The asterisms are :...

or Heaven's Kitchen, refers to an asterism
Asterism
Asterism may refer to:* Asterism , a pattern of stars* Asterism , an optical phenomenon in gemstones* Asterism , a moderately rare typographical symbol denoting a break in passages...

 consisting of δ Draconis, σ Draconis
Sigma Draconis
Sigma Draconis is a 4.7 magnitude star located at a distance of 18.8 light-years in the constellation Draco. Its traditional name is Alsafi.-Name:...

, ε Draconis
Epsilon Draconis
Epsilon Draconis is a fourth-magnitude star in the constellation Draco. It has the traditional name Tyl. This star along with Delta Draconis , Pi Draconis and Rho Draconis forms an asterism known as Al Tāis, meaning "the Goat".In Chinese astronomy, , meaning the Celestial Kitchen, refers to an...

, ρ Draconis, 64 Draconis and π Draconis. Consequently, δ Draconis itself is known as

Structure

Delta Draconis is a giant star
Giant star
A giant star is a star with substantially larger radius and luminosity than a main sequence star of the same surface temperature. Typically, giant stars have radii between 10 and 100 solar radii and luminosities between 10 and 1,000 times that of the Sun. Stars still more luminous than giants are...

 with a stellar classification
Stellar classification
In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...

 of G9III. At a distance of approximately 100 light years from Earth
Earth
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...

, it has an apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...

 of 3.0. The angular diameter of the star is estimated as . At a parallax
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. The term is derived from the Greek παράλλαξις , meaning "alteration"...

 of 32.54 mas, this corresponds to a physical radius equal to 11 times the solar radius.
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