Star · M3
GJ 3999A
GJ 3999A is a main-sequence star of spectral type M3 in the constellation Serpens, 88.7 light-years from the Sun.
| Constellation | Serpens |
|---|---|
| Distance | 88.7 light-years (27.2 pc) |
| Apparent magnitude | magnitude 12.83 |
| Absolute magnitude | magnitude 10.66 |
| Spectral type | M3 |
| Surface temperature | 3,810 K |
| Luminosity | 0.0168 L☉ |
| Radius | 0.298 R☉ |
| Mass | 0.321 M☉ (estimated) |
| Right ascension (J2000) | 17h 17m 44.3s |
| Declination (J2000) | −11° 50′ 06″ |
| Space velocity (relative to the Sun) | 37.6 km/s |
In the sky
A telescope is needed to see it: its apparent magnitude is 12.83. Visible from the whole Southern Hemisphere and north to latitude 78° N. South of latitude 78° S 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 1937. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 1.6 million years.
The Sun seen from there
From a planet around GJ 3999A, the Sun would look like a star of magnitude 7.00, in the direction where our sky has the constellation Orion. 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.