Star · M0III
HIP 1821
HIP 1821 is a giant star of spectral type M0III in the constellation Cetus, 799.9 light-years from the Sun.
| Constellation | Cetus |
|---|---|
| Distance | 799.9 light-years (245.3 pc) |
| Apparent magnitude | magnitude 6.43 |
| Absolute magnitude | magnitude −0.52 |
| Spectral type | M0III |
| Surface temperature | 3,660 K |
| Luminosity | 616 L☉ |
| Radius | 61.9 R☉ |
| Mass | 5.69 M☉ (estimated) |
| Right ascension (J2000) | 0h 23m 04.4s |
| Declination (J2000) | −15° 56′ 33″ |
| Space velocity (relative to the Sun) | 97.1 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 6.43). Visible from the whole Southern Hemisphere and north to latitude 74° N. South of latitude 74° S 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 1226. 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 HIP 1821, the Sun would look like a star of magnitude 11.78, in the direction where our sky has the constellation Coma Berenices. 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.