Star · B2IV
121 Tau
121 Tau is a subgiant star of spectral type B2IV in the constellation Taurus, 642.6 light-years from the Sun.
| Other names | HIP 26248 |
|---|---|
| Constellation | Taurus |
| Distance | 642.6 light-years (197.0 pc) |
| Apparent magnitude | magnitude 5.37 |
| Absolute magnitude | magnitude −1.10 |
| Spectral type | B2IV |
| Surface temperature | 11,440 K |
| Luminosity | 411 L☉ |
| Radius | 5.16 R☉ |
| Mass | 5.07 M☉ (estimated) |
| Right ascension (J2000) | 5h 35m 27.1s |
| Declination (J2000) | +24° 02′ 23″ |
| Space velocity (relative to the Sun) | 30.3 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 5.37). Visible from the whole Northern Hemisphere and south to latitude 66° S. North of latitude 66° 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 the year 1383. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 11 million years.
The Sun seen from there
From a planet around 121 Tau, the Sun would look like a star of magnitude 11.30, in the direction where our sky has the constellation Ophiuchus. 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.