Star · M2III
21 Cnc
21 Cnc is a giant star of spectral type M2III in the constellation Cancer, 790.5 light-years from the Sun.
| Other names | HIP 41163 |
|---|---|
| Constellation | Cancer |
| Distance | 790.5 light-years (242.4 pc) |
| Apparent magnitude | magnitude 6.11 |
| Absolute magnitude | magnitude −0.81 |
| Spectral type | M2III |
| Surface temperature | 3,780 K |
| Luminosity | 675 L☉ |
| Radius | 60.5 R☉ |
| Mass | 5.84 M☉ (estimated) |
| Right ascension (J2000) | 8h 23m 55.2s |
| Declination (J2000) | +10° 37′ 55″ |
| Space velocity (relative to the Sun) | 26.7 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 6.11). Visible from the whole Northern Hemisphere and south to latitude 79° S. North of latitude 79° N it never sets. It stands highest at midnight in January, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1235. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 14 million years.
The Sun seen from there
From a planet around 21 Cnc, the Sun would look like a star of magnitude 11.75, in the direction where our sky has the constellation Capricornus. It would be invisible to the naked eye.
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.