Star · K0V
GJ 2157
GJ 2157 is a main-sequence star of spectral type K0V in the constellation Cassiopeia, 229.1 light-years from the Sun.
| Other names | HIP 116743 |
|---|---|
| Constellation | Cassiopeia |
| Distance | 229.1 light-years (70.2 pc) |
| Apparent magnitude | magnitude 7.53 |
| Absolute magnitude | magnitude 3.30 |
| Spectral type | K0V |
| Surface temperature | 5,090 K |
| Luminosity | 5.42 L☉ |
| Radius | 2.99 R☉ |
| Mass | 1.53 M☉ (estimated) |
| Right ascension (J2000) | 23h 39m 35.0s |
| Declination (J2000) | +58° 58′ 14″ |
| Space velocity (relative to the Sun) | 32.7 km/s |
In the sky
Too faint for the naked eye (magnitude 7.53); binoculars will find it. Visible from the whole Northern Hemisphere and south to latitude 31° S. North of latitude 31° N it never sets. It stands highest at midnight in September, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1797. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 4.1 million years.
The Sun seen from there
From a planet around GJ 2157, the Sun would look like a star of magnitude 9.06, in the direction where our sky has the constellation Centaurus. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- HIP 116251 7.22 light-years
- HIP 352 14.2 light-years
- HIP 117617 15.6 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.