Star · A5V
18 UMa
18 UMa is a main-sequence star of spectral type A5V in the constellation Ursa Major, 116.9 light-years from the Sun.
| Other names | GJ 3541 · HIP 45493 |
|---|---|
| Constellation | Ursa Major |
| Distance | 116.9 light-years (35.8 pc) |
| Apparent magnitude | magnitude 4.80 |
| Absolute magnitude | magnitude 2.03 |
| Spectral type | A5V |
| Surface temperature | 8,170 K |
| Luminosity | 14.2 L☉ |
| Radius | 1.88 R☉ |
| Mass | 1.94 M☉ (estimated) |
| Right ascension (J2000) | 9h 16m 11.3s |
| Declination (J2000) | +54° 01′ 19″ |
| Space velocity (relative to the Sun) | 21.9 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 4.80). Visible from the whole Northern Hemisphere and south to latitude 36° S. North of latitude 36° N it never sets. It stands highest at midnight in February, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1909. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 2.1 million years.
The Sun seen from there
From a planet around 18 UMa, the Sun would look like a star of magnitude 7.60, in the direction where our sky has the constellation Indus. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.