Magnitude 5.66 Apparent magnitude (V) 5.66 | Constellation Aquarius | |
 | ||
People also search for Omega1 Aquarii, Omega2 Aquarii | ||
Tau1 Aquarii (τ1 Aqr, τ1 Aquarii) is the Bayer designation for a star in the equatorial constellation of Aquarius. With an apparent visual magnitude of 5.66, it is a faint naked eye that requires dark suburban skies for viewing. Parallax measurements made during the Hipparcos mission yield a distance estimate of roughly 320 light-years (98 parsecs) from Earth.
τ1 Aquarii has a stellar classification of B9 V; right along the borderline between a B- and A-type main sequence star. It is around 100 million years old and has twice the Sun's radius. When examined in the infrared band, it displays an excess emission that is a characteristic of stars with an orbiting debris disk. Indeed, the model that best fits the data suggests there are two concentric circumstellar disks.