Star · M3
GJ 3817
GJ 3817 is a main-sequence star of spectral type M3 in the constellation Boötes, 30.5 light-years from the Sun.
| Constellation | Boötes |
|---|---|
| Distance | 30.5 light-years (9.36 pc) |
| Apparent magnitude | magnitude 12.26 |
| Absolute magnitude | magnitude 12.40 |
| Spectral type | M3 |
| Surface temperature | 3,570 K |
| Luminosity | 0.0048 L☉ |
| Radius | 0.181 R☉ |
| Mass | 0.186 M☉ (estimated) |
| Right ascension (J2000) | 13h 58m 14.5s |
| Declination (J2000) | +12° 34′ 42″ |
| Space velocity (relative to the Sun) | 35.1 km/s |
In the sky
A telescope is needed to see it: its apparent magnitude is 12.26. Visible from the whole Northern Hemisphere and south to latitude 77° S. North of latitude 77° N it never sets. It stands highest at midnight in April, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1995. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 542 thousand years.
The Sun seen from there
From a planet around GJ 3817, the Sun would look like a star of magnitude 4.69, in the direction where our sky has the constellation Cetus. It would be visible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- ULAS J133553.45+113005.2 3.73 light-years
- ULAS J131943.77+120900.2 5.13 light-years
- Gl 518 6.17 light-years
- GJ 514 6.64 light-years
- Muphrid 7.49 light-years
- Arcturus 7.69 light-years
- Gl 569A 7.94 light-years
- HD 115404 A 8.24 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.