Star · B9V
4 Sgr
4 Sgr is a main-sequence star of spectral type B9V in the constellation Sagittarius, 408.3 light-years from the Sun.
| Other names | HIP 88116 |
|---|---|
| Constellation | Sagittarius |
| Distance | 408.3 light-years (125.2 pc) |
| Apparent magnitude | magnitude 4.74 |
| Absolute magnitude | magnitude −0.75 |
| Spectral type | B9V |
| Surface temperature | 10,520 K |
| Luminosity | 255 L☉ |
| Radius | 4.81 R☉ |
| Mass | 4.42 M☉ (estimated) |
| Right ascension (J2000) | 17h 59m 47.5s |
| Declination (J2000) | −23° 48′ 58″ |
| Space velocity (relative to the Sun) | 71.1 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 4.74). Visible from the whole Southern Hemisphere and north to latitude 66° N. South of latitude 66° S it never sets. It stands highest at midnight in June, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1618. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 7.2 million years.
The Sun seen from there
From a planet around 4 Sgr, the Sun would look like a star of magnitude 10.32, in the direction where our sky has the constellation Taurus. 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.