Star · F6 IV
Kepler-21
Kepler-21 is a subgiant star of spectral type F6 IV in the constellation Lyra, 353.8 light-years from the Sun. It is orbited by 1 confirmed exoplanet(s).
| Other names | HIP 94112 |
|---|---|
| Constellation | Lyra |
| Distance | 353.8 light-years (108.5 pc) |
| Apparent magnitude | magnitude 8.25 |
| Absolute magnitude | magnitude 3.07 |
| Spectral type | F6 IV |
| Surface temperature | 6,310 K |
| Luminosity | 5.19 L☉ |
| Radius | 1.9 R☉ |
| Mass | 1.41 M☉ |
| Age | 2.8 billion years |
| Metallicity [Fe/H] | -0.03 |
| Right ascension (J2000) | 19h 09m 26.8s |
| Declination (J2000) | +38° 42′ 50″ |
| Space velocity (relative to the Sun) | 28.2 km/s |
In the sky
Too faint for the naked eye (magnitude 8.25); binoculars will find it. Visible from the whole Northern Hemisphere and south to latitude 51° S. North of latitude 51° 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 around the year 1672. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 6.3 million years.
The Sun seen from there
From a planet around Kepler-21, the Sun would look like a star of magnitude 10.01, in the direction where our sky has the constellation Puppis. It would be invisible to the naked eye.
Planets
- Kepler-21 b 2.79-day orbit · 1.64 R⊕
Stellar parameters from the NASA Exoplanet Archive; position and brightness from the HYG / AT-HYG catalogue.