Star · M3III
Propus
Propus is a giant star of spectral type M3III in the constellation Gemini, 689.4 light-years from the Sun.
| Other names | η Gem · HIP 29655 |
|---|---|
| Constellation | Gemini |
| Distance | 689.4 light-years (211.4 pc) |
| Apparent magnitude | magnitude 3.31 |
| Absolute magnitude | magnitude −3.32 |
| Spectral type | M3III |
| Surface temperature | 3,650 K |
| Luminosity | 8,180 L☉ |
| Radius | 226 R☉ |
| Mass | 11.9 M☉ (estimated) |
| Right ascension (J2000) | 6h 14m 52.7s |
| Declination (J2000) | +22° 30′ 24″ |
| Space velocity (relative to the Sun) | 64.2 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 3.31). Visible from the whole Northern Hemisphere and south to latitude 67° S. North of latitude 67° N it never sets. It stands highest at midnight in December, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1337. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 12 million years.
The Sun seen from there
From a planet around Propus, the Sun would look like a star of magnitude 11.46, in the direction where our sky has the constellation Sagittarius. 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.