Star · B5II
30 Cap
30 Cap is a bright giant star of spectral type B5II in the constellation Capricornus, 762.6 light-years from the Sun.
| Other names | HIP 105143 |
|---|---|
| Constellation | Capricornus |
| Distance | 762.6 light-years (233.8 pc) |
| Apparent magnitude | magnitude 5.40 |
| Absolute magnitude | magnitude −1.44 |
| Spectral type | B5II |
| Surface temperature | 11,880 K |
| Luminosity | 605 L☉ |
| Radius | 5.8 R☉ |
| Mass | 5.66 M☉ (estimated) |
| Right ascension (J2000) | 21h 17m 57.3s |
| Declination (J2000) | −17° 59′ 06″ |
| Space velocity (relative to the Sun) | 18.2 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 5.40). Visible from the whole Southern Hemisphere and north to latitude 72° N. South of latitude 72° S it never sets. It stands highest at midnight in August, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1263. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 14 million years.
The Sun seen from there
From a planet around 30 Cap, the Sun would look like a star of magnitude 11.67, in the direction where our sky has the constellation Cancer. 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.