Theta Sagittarii
Encyclopedia
The Bayer designation
Theta Sagittarii (θ Sgr, θ Sagittarii) is shared by two star system
s, θ¹ Sagittarii and θ² Sagittarii, in the constellation
Sagittarius
. The two stars are separated by 0.58° in the sky.
from Earth
. The primary star, θ¹ Sagittarii A, is a spectral type
B2.5 subgiant which has an apparent magnitude
of +4.37. The companion star, θ¹ Sagittarii B, is approximately 0.2 arcseconds from the primary, which puts them 31 astronomical units (AU) apart (a Sun
-Neptune
distance).
from Earth
. θ² Sagittarii A is a spectral type
A4/5 subgiant which has an apparent magnitude
of +5.30. Orbiting the primary with a separation on the sky of 30 arcseconds, or at least 1400 AU, is binary star
composed of θ² Sagittarii B, a magnitude +10.8 star, and θ² Sagittarii C, with a magnitude of +11.5. B and C are 1.2 arcseconds, or approximately 58 AU apart.
Bayer designation
A Bayer designation is a stellar designation in which a specific star is identified by a Greek letter, followed by the genitive form of its parent constellation's Latin name...
Theta Sagittarii (θ Sgr, θ Sagittarii) is shared by two star system
Star system
A star system or stellar system is a small number of stars which orbit each other, bound by gravitational attraction. A large number of stars bound by gravitation is generally called a star cluster or galaxy, although, broadly speaking, they are also star systems.-Binary star systems:A stellar...
s, θ¹ Sagittarii and θ² Sagittarii, 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....
Sagittarius
Sagittarius (constellation)
Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...
. The two stars are separated by 0.58° in the sky.
θ¹ Sagittarii
Theta-1 Sagittarii is a spectroscopic binary lying 617 light yearsLight 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
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...
. The primary star, θ¹ Sagittarii A, is a spectral 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...
B2.5 subgiant which 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 +4.37. The companion star, θ¹ Sagittarii B, is approximately 0.2 arcseconds from the primary, which puts them 31 astronomical units (AU) apart (a Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
-Neptune
Neptune
Neptune is the eighth and farthest planet from the Sun in the Solar System. Named for the Roman god of the sea, it is the fourth-largest planet by diameter and the third largest by mass. Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times...
distance).
θ² Sagittarii
Theta-2 Sagittarii is a triple star system 157 light yearsLight 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
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...
. θ² Sagittarii A is a spectral 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...
A4/5 subgiant which 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 +5.30. Orbiting the primary with a separation on the sky of 30 arcseconds, or at least 1400 AU, is 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...
composed of θ² Sagittarii B, a magnitude +10.8 star, and θ² Sagittarii C, with a magnitude of +11.5. B and C are 1.2 arcseconds, or approximately 58 AU apart.