Star · B1I
139 Tau
139 Tau is a supergiant star of spectral type B1I in the constellation Taurus, 3,786 light-years from the Sun.
| Other names | HIP 28237 |
|---|---|
| Constellation | Taurus |
| Distance | 3,786 light-years (1,161 pc) |
| Apparent magnitude | magnitude 4.81 |
| Absolute magnitude | magnitude −5.51 |
| Spectral type | B1I |
| Surface temperature | 11,370 K |
| Luminosity | 23,600 L☉ |
| Radius | 39.6 R☉ |
| Mass | 16.1 M☉ (estimated) |
| Right ascension (J2000) | 5h 57m 59.7s |
| Declination (J2000) | +25° 57′ 14″ |
| Space velocity (relative to the Sun) | 17.6 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 4.81). Visible from the whole Northern Hemisphere and south to latitude 64° S. North of latitude 64° N it never sets. It stands highest at midnight in December, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around 1761 BC. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 67 million years.
The Sun seen from there
From a planet around 139 Tau, the Sun would look like a star of magnitude 15.15, in the direction where our sky has the constellation Sagittarius. It would be invisible to the naked eye.
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.