Star · M3
GJ 3991
GJ 3991 is a main-sequence star of spectral type M3 in the constellation Hercules, 24.8 light-years from the Sun.
| Other names | HIP 83945 |
|---|---|
| Constellation | Hercules |
| Distance | 24.8 light-years (7.60 pc) |
| Apparent magnitude | magnitude 11.77 |
| Absolute magnitude | magnitude 12.37 |
| Spectral type | M3 |
| Surface temperature | 3,520 K |
| Luminosity | 0.00537 L☉ |
| Radius | 0.197 R☉ |
| Mass | 0.195 M☉ (estimated) |
| Right ascension (J2000) | 17h 09m 31.3s |
| Declination (J2000) | +43° 40′ 56″ |
| Space velocity (relative to the Sun) | 31.9 km/s |
In the sky
A telescope is needed to see it: its apparent magnitude is 11.77. Visible from the whole Northern Hemisphere and south to latitude 46° S. North of latitude 46° N it never sets. It stands highest at midnight in June, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 2001. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 440 thousand years.
The Sun seen from there
From a planet around GJ 3991, the Sun would look like a star of magnitude 4.23, in the direction where our sky has the constellation Pictor. It would be visible 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.