Theta Aquilae
Encyclopedia
Theta Aquilae (θ Aql, θ Aquilae) is a binary star
Binary star
A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...

 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....

 Aquila
Aquila (constellation)
Aquila is a stellar constellation. Its name is Latin for 'eagle' and it is commonly represented as such. In mythology, Aquila was owned by the Roman god Jupiter and performed many tasks for him....

. It is approximately 287 light years
Light Years
Light Years is the seventh studio album by Australian recording artist Kylie Minogue. It was released on 25 September 2000 by Parlophone and Mushroom Records. The album's style was indicative of her return to "mainstream pop dance tunes"....

 from Earth. It has the traditional name Tseen Foo, which is derived from the Mandarin
Standard Mandarin
Standard Chinese or Modern Standard Chinese, also known as Mandarin or Putonghua, is the official language of the People's Republic of China and Republic of China , and is one of the four official languages of Singapore....

 天桴 tiānfú meaning "the heavenly raft(er)"; it may also mean drumsticks, with Altair, Beta Aquilae and Gamma Aquilae being the drum.

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 Drumstick
Ox (Chinese constellation)
The Ox mansion is one of the Twenty-eight mansions of the Chinese constellations. It is one of the northern mansions of the Black Tortoise.-Asterisms:...

, refers to an asterism consisting of θ Aquilae, 62 Aquilae
62 Aquilae
62 Aquilae is a star in the constellation Aquila. Its apparent magnitude is 5.67....

, 58 Aquilae
58 Aquilae
58 Aquilae is a star in the constellation Aquila. Its apparent magnitude is 5.60.It is a constellation in the Northern Hemisphere and the Milky Way near Aquarius and Serpens Cauda....

 and η Aquilae
Eta Aquilae
Eta Aquilae is a star in the constellation Aquila. It was also part of the former constellation Antinous. It is a Cepheid variable star, varying from apparent magnitude 3.5 to 4.4 with a period of 7.176641 days...

. Consequently, θ Aquilae itself is known as

In the catalogue of stars in the Calendarium of Al Achsasi al Mouakket
Al Achsasi al Mouakket
Mohammad Al Achsasi Al Mouakket was an Egyptian astronomer whose calendarium and catalogue of stars, entitled Durret al Muddiah Fih al Aamal al Shamsiah , was written at Cairo about 1650.Al Achsasi was sheikh of the Grand Mosque of the University of Cairo, where his name al...

, this star was designated Thanih Ras al Akab (تاني ألرأس ألعقاب - taanii al ra’s alʕuqāb), which was translated into Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 as Secunda Capitis Vulturis, meaning the second (star) of eagle's head.

This star, along with δ Aql
Delta Aquilae
Delta Aquilae is a triple star system in the constellation Aquila. It is approximately 50.1 light years from Earth.Sometimes, this star is called by the name Denebokab, meaning the tail of eagle in Arabic...

 (Denebokab) and η Aql
Eta Aquilae
Eta Aquilae is a star in the constellation Aquila. It was also part of the former constellation Antinous. It is a Cepheid variable star, varying from apparent magnitude 3.5 to 4.4 with a period of 7.176641 days...

, were Al Mizān (ألميزان), the Scale-beam.. According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Al Mizān were the title for three stars :δ Aql
Delta Aquilae
Delta Aquilae is a triple star system in the constellation Aquila. It is approximately 50.1 light years from Earth.Sometimes, this star is called by the name Denebokab, meaning the tail of eagle in Arabic...

 as Al Mizān I, η Aql
Eta Aquilae
Eta Aquilae is a star in the constellation Aquila. It was also part of the former constellation Antinous. It is a Cepheid variable star, varying from apparent magnitude 3.5 to 4.4 with a period of 7.176641 days...

 as l Mizān II and θ Aql as Al Mizān III

Structure

Theta Aquilae is a spectroscopic binary classified as a blue-white B-type
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...

 giant
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 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 +3.24. The binary has an orbital period of 17.123 days.
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