Star · B3I
55 Cyg
55 Cyg is a supergiant star of spectral type B3I in the constellation Cygnus, 6,001 light-years from the Sun.
| Other names | HIP 102724 |
|---|---|
| Constellation | Cygnus |
| Distance | 6,001 light-years (1,840 pc) |
| Apparent magnitude | magnitude 4.81 |
| Absolute magnitude | magnitude −6.51 |
| Spectral type | B3I |
| Surface temperature | 6,080 K |
| Luminosity | 35,700 L☉ |
| Radius | 170 R☉ |
| Mass | 18.2 M☉ (estimated) |
| Right ascension (J2000) | 20h 48m 56.3s |
| Declination (J2000) | +46° 06′ 51″ |
| Space velocity (relative to the Sun) | 30.2 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 4.81). Visible from the whole Northern Hemisphere and south to latitude 44° S. North of latitude 44° N it never sets. It stands highest at midnight in August, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 6,001 years ago. At that time the first farming villages were being founded; there was no writing yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 106 million years.
The Sun seen from there
From a planet around 55 Cyg, the Sun would look like a star of magnitude 16.15, in the direction where our sky has the constellation Vela. 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.