Star · B0V
40 Per
40 Per is a main-sequence star of spectral type B0V in the constellation Perseus, 1,206 light-years from the Sun.
| Other names | HIP 17313 |
|---|---|
| Constellation | Perseus |
| Distance | 1,206 light-years (369.9 pc) |
| Apparent magnitude | magnitude 4.97 |
| Absolute magnitude | magnitude −2.87 |
| Spectral type | B0V |
| Surface temperature | 10,770 K |
| Luminosity | 1,870 L☉ |
| Radius | 12.4 R☉ |
| Mass | 7.82 M☉ (estimated) |
| Right ascension (J2000) | 3h 42m 22.6s |
| Declination (J2000) | +33° 57′ 54″ |
| Space velocity (relative to the Sun) | 22.4 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 4.97). Visible from the whole Northern Hemisphere and south to latitude 56° S. North of latitude 56° N it never sets. It stands highest at midnight in November, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 820. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 21 million years.
The Sun seen from there
From a planet around 40 Per, the Sun would look like a star of magnitude 12.67, in the direction where our sky has the constellation Lupus. 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.