Star · B
KOI-55
KOI-55 is a main-sequence star of spectral type B in the constellation Cygnus, 4,015 light-years from the Sun. It is orbited by 2 confirmed exoplanet(s).
| Constellation | Cygnus |
|---|---|
| Distance | 4,015 light-years (1,231 pc) |
| Apparent magnitude | magnitude 15.15 |
| Absolute magnitude | magnitude 4.70 |
| Spectral type | B |
| Surface temperature | 27,730 K |
| Luminosity | 22.9 L☉ |
| Radius | 0.203 R☉ |
| Mass | 0.496 M☉ |
| Metallicity [Fe/H] | -0.11 |
| Right ascension (J2000) | 19h 45m 25.5s |
| Declination (J2000) | +41° 05′ 34″ |
| Space velocity (relative to the Sun) | 45.7 km/s |
In the sky
A telescope is needed to see it: its apparent magnitude is 15.15. Visible from the whole Northern Hemisphere and south to latitude 49° S. North of latitude 49° N it never sets. It stands highest at midnight in July, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 4,015 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 71 million years.
The Sun seen from there
From a planet around KOI-55, the Sun would look like a star of magnitude 15.28, in the direction where our sky has the constellation Puppis. It would be invisible to the naked eye.
Planets
Stellar parameters from the NASA Exoplanet Archive; position and brightness from the HYG / AT-HYG catalogue.