Star · B9I
ξ¹ Sgr
ξ¹ Sgr is a supergiant star of spectral type B9I in the constellation Sagittarius, 2,221 light-years from the Sun.
| Other names | HIP 93057 |
|---|---|
| Constellation | Sagittarius |
| Distance | 2,221 light-years (681.0 pc) |
| Apparent magnitude | magnitude 5.02 |
| Absolute magnitude | magnitude −4.15 |
| Spectral type | B9I |
| Surface temperature | 8,690 K |
| Luminosity | 4,440 L☉ |
| Radius | 29.4 R☉ |
| Mass | 10 M☉ (estimated) |
| Right ascension (J2000) | 18h 57m 20.5s |
| Declination (J2000) | −20° 39′ 23″ |
| Space velocity (relative to the Sun) | 20.0 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 5.02). Visible from the whole Southern Hemisphere and north to latitude 69° N. South of latitude 69° S it never sets. It stands highest at midnight in July, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around 196 BC. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 39 million years.
The Sun seen from there
From a planet around ξ¹ Sgr, the Sun would look like a star of magnitude 14.00, in the direction where our sky has the constellation Gemini. 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.