alf Tau is 66.6 light-years from the Sun. The NASA Exoplanet Archive lists 1 planet around this K5 III star; the first was found in 2015 by radial velocity (Multiple Observatories).
Fly there in 3Dalf Tau b takes 629.0 days to go round its star once.
alf Tau is one of 2 stars in its system: the other is drawn where the Washington Double Star Catalog measures it on the sky.
| Spectral type | K5 III |
| Surface temperature | 4,055 K |
| Mass | 1.13 solar masses |
| Radius | 45.1 solar radii |
| Luminosity | 469.9 times the Sun |
| Apparent magnitude | 0.872 |
| Age | about 6.6 billion years |
| Distance from the Sun | 66.6 light-years (20.4 parsecs) |
| Position (J2000) | RA 68.9802°, Dec 16.5092° |
| Constellation | Taurus |
alf Tau B is a M2 star of magnitude 13.6, moving through space with it. In 2023 it was 31.4″ from alf Tau, at position angle 115° (Washington Double Star Catalog, 04359+1631 BU 550 AB): 642 AU on the sky at this distance. The true distance can only be larger.
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| alf Tau b disputed | 629.0 days | 1.460 AU | 12.7 R⊕ estimated | 2056.4 M⊕ minimum | Radial Velocity, 2015 |
Values are the NASA Exoplanet Archive’s composite parameters. A radius marked estimated comes from a mass–radius relation; a mass marked minimum is M sin i. Planet sizes and colours in the 3D view are renderings: none of these worlds has been photographed as more than a point of light.