Star · K9V
GJ 2121
GJ 2121 is a main-sequence star of spectral type K9V in the constellation Ophiuchus, 73.9 light-years from the Sun.
| Other names | HIP 80817 |
|---|---|
| Constellation | Ophiuchus |
| Distance | 73.9 light-years (22.6 pc) |
| Apparent magnitude | magnitude 12.27 |
| Absolute magnitude | magnitude 10.50 |
| Spectral type | K9V |
| Surface temperature | 3,830 K |
| Luminosity | 0.0189 L☉ |
| Radius | 0.312 R☉ |
| Mass | 0.338 M☉ (estimated) |
| Right ascension (J2000) | 16h 30m 13.4s |
| Declination (J2000) | −14° 39′ 48″ |
| Space velocity (relative to the Sun) | 118.5 km/s |
In the sky
A telescope is needed to see it: its apparent magnitude is 12.27. Visible from the whole Southern Hemisphere and north to latitude 75° N. South of latitude 75° S 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 1952. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 1.3 million years.
The Sun seen from there
From a planet around GJ 2121, the Sun would look like a star of magnitude 6.60, in the direction where our sky has the constellation Taurus. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- Gl 621 4.80 light-years
- PSO J246.1033-19.6194 6.64 light-years
- HIP 80612 8.08 light-years
- GJ 1198 9.24 light-years
- CWISE J163041.79-064338.3 11.4 light-years
- GJ 3973 13.1 light-years
- 2MASS J17065487-1314396 14.5 light-years
- WISEPA J162208.94-095934.6 15.3 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.