Zeta Sagittarii
From Wikipedia, the free encyclopedia
 |
This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (August 2009) |
| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Sagittarius |
| Right ascension | 19h 02m 36.7s |
| Declination | -29° 52' 49" |
| Apparent magnitude (V) | +2.60 |
| Distance | 89.1 ± 3.3 ly (27.3 ± 1 pc) |
| Spectral type | A2III+A4IV |
| Other designations | |
Zeta Sagittarii (ζ Sgr / ζ Sagittarii) is the third brightest star system in the constellation Sagittarius. It has the traditional name Ascella from a Late Latin word meaning armpit.
Ascella is a binary star, consisting of a spectral class A2 giant with an apparent magnitude of +3.26, and an A4 subgiant with apparent magnitude of +3.37. The orbital period of the binary system is 21 years. The two stars have a mean separation of 13.4 astronomical units (AU) and the eccentricity of their orbit is 0.205. Ascella has a faint, 10th magnitude companion, Zeta Sagittarii C, separated from the primary by a distance of 75 arcseconds.
Ascella is 90 light years from Earth. The combined apparent magnitude of the star system is +2.60.
In ancient Chinese astronomy, it is the 6th star of 6 stars in the Dipper or 'South Dipper' mansion of the Black Tortoise of the North.
 |
This binary or multiple star system-related article is a stub. You can help Wikipedia by expanding it. |
