Star · M2
GJ 3947
GJ 3947 is a main-sequence star of spectral type M2 in the constellation Hercules, 83.1 light-years from the Sun.
| Constellation | Hercules |
|---|---|
| Distance | 83.1 light-years (25.5 pc) |
| Apparent magnitude | magnitude 11.99 |
| Absolute magnitude | magnitude 9.96 |
| Spectral type | M2 |
| Surface temperature | 3,780 K |
| Luminosity | 0.0334 L☉ |
| Radius | 0.426 R☉ |
| Mass | 0.427 M☉ (estimated) |
| Right ascension (J2000) | 16h 15m 32.1s |
| Declination (J2000) | +24° 27′ 43″ |
| Space velocity (relative to the Sun) | 30.9 km/s |
In the sky
A telescope is needed to see it: its apparent magnitude is 11.99. Visible from the whole Northern Hemisphere and south to latitude 66° S. North of latitude 66° N it never sets. It stands highest at midnight in May, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1943. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 1.5 million years.
The Sun seen from there
From a planet around GJ 3947, the Sun would look like a star of magnitude 6.86, in the direction where our sky has the constellation Eridanus. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- GJ 9533 8.37 light-years
- GJ 1197 10.5 light-years
- 2MASSW J1553214+210907 12.4 light-years
- Gl 632.1 12.7 light-years
- Gl 609.2 13.1 light-years
- GJ 3935A 13.9 light-years
- GJ 3936B 14.0 light-years
- WISEA J162852.64+160421.0 14.2 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.