Star · F9V
Kepler-557
Kepler-557 is a main-sequence star of spectral type F9V in the constellation Cygnus, 6,840 light-years from the Sun. It is orbited by 1 confirmed exoplanet(s).
| Constellation | Cygnus |
|---|---|
| Distance | 6,840 light-years (2,097 pc) |
| Apparent magnitude | magnitude 14.72 |
| Absolute magnitude | magnitude 3.11 |
| Spectral type | F9V |
| Surface temperature | 6,070 K |
| Luminosity | 5.35 L☉ |
| Radius | 1.16 R☉ |
| Mass | 1.11 M☉ |
| Age | 3.2 billion years |
| Metallicity [Fe/H] | 0.02 |
| Right ascension (J2000) | 19h 34m 50.0s |
| Declination (J2000) | +41° 36′ 54″ |
| Space velocity (relative to the Sun) | 94.9 km/s |
In the sky
A telescope is needed to see it: its apparent magnitude is 14.72. Visible from the whole Northern Hemisphere and south to latitude 48° S. North of latitude 48° 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 6,840 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 121 million years.
The Sun seen from there
From a planet around Kepler-557, the Sun would look like a star of magnitude 16.44, in the direction where our sky has the constellation Puppis. It would be invisible to the naked eye.
Planets
- Kepler-557 b 3.71-day orbit · 2.67 R⊕
Stellar parameters from the NASA Exoplanet Archive; position and brightness from the HYG / AT-HYG catalogue.