Pi Sagittarii

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π Sagittarii
Observation data
Epoch J2000.0
Constellation
(pronunciation)		 Sagittarius
Right ascension 19h 09m 45.8s
Declination -21° 01' 25"
Apparent magnitude (V) +2.88
Distance 440 ± 41 ly
(135 ± 13 pc)
Spectral type F2II/III
Other designations
Albaldah, 41 Sagittarii,
HR 7264, HD 178524,
SAO 187756, HIP 94141,
CCDM 19098-2101

Pi Sagittarii (π Sgr / π Sagittarii) is a triple star system in the constellation Sagittarius. It also has the traditional name Albaldah. It is known as 建三 (the Third Star of the Establishment) in Chinese. The star is 440 light years from Earth.

Albaldah has an apparent magnitude of +2.88 and belongs to the spectral class F2II. Albaldah has two companions in close orbits. Pi Sagittarii B is located 0.1 arcseconds from Albaldah, or at least 13 Astronomical Units (AU). The second companion, the 6th magnitude Pi Sagittarii C, is 0.4 arcseconds away, or at least 40 AU.

Because it is close to the ecliptic, Albaldah can sometimes be occulted by the Moon, and very rarely, planets of our solar system. The next occultation by a planet takes place on February 17, 2035 when it will be occulted by Venus.

[edit] Etymology

The name Albalda comes from the Arabic البلطة al-balţah 'the axe' (or 'the city'?).

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