Star · ?
GJ 3646
GJ 3646 is a main-sequence star of spectral type ? in the constellation Ursa Major, 78.7 light-years from the Sun.
| Constellation | Ursa Major |
|---|---|
| Distance | 78.7 light-years (24.1 pc) |
| Apparent magnitude | magnitude 14.52 |
| Absolute magnitude | magnitude 12.61 |
| Spectral type | ? |
| Surface temperature | 3,650 K |
| Luminosity | 0.0035 L☉ |
| Radius | 0.148 R☉ |
| Mass | 0.162 M☉ (estimated) |
| Right ascension (J2000) | 11h 10m 52.5s |
| Declination (J2000) | +47° 57′ 01″ |
| Space velocity (relative to the Sun) | 68.5 km/s |
In the sky
A telescope is needed to see it: its apparent magnitude is 14.52. Visible from the whole Northern Hemisphere and south to latitude 42° S. North of latitude 42° N it never sets. It stands highest at midnight in March, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1947. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 1.4 million years.
The Sun seen from there
From a planet around GJ 3646, the Sun would look like a star of magnitude 6.74, in the direction where our sky has the constellation Grus. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- HIP 55507 5.27 light-years
- 2MASS J11000965+4957470 5.90 light-years
- GJ 3628B 7.56 light-years
- Gl 433.2A 7.98 light-years
- Gl 433.2B 8.10 light-years
- WISE J105047.90+505606.2 8.78 light-years
- GJ 3610A 8.80 light-years
- HIP 57493 9.14 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.