binary star
A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in wh ...
constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The origins of the e ...
of Aquarius. It has a peak apparent visual magnitude of 5.89, which is bright enough to be visible to the naked eye. The distance can be estimated from its annual parallax shift of , yielding a separation of 291
light year
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...
s.
This is a detachedeclipsing binary system of the Beta Lyrae type. The orbital period for the system is 1.5755 days and the eccentricity is unknown and probably non-zero; the orbital inclination is estimated to be . During the primary eclipse the magnitude drops to 6.25. It descends to 6.10 with the secondary eclipse (with 6.10 being brighter than 6.25). The pair have been identified as candidate Herbig Ae/Be stars, and catalogued as A-type shell stars.
A magnitude 10.8 star with the designation HD 358087 is a common proper motion companion. It is located at an
angular separation
Angular distance \theta (also known as angular separation, apparent distance, or apparent separation) is the angle between the two sightlines, or between two point objects as viewed from an observer.
Angular distance appears in mathematics (in pa ...
of and has 78% of the Sun's mass. If it is gravitationally bound to the main system, the orbital period is estimated to be around 611,855 years