Kepler-21
Sign in to saveKepler-21, also known as HD 179070, is a star with a closely orbiting exoplanet in the northern constellation of Lyra. At an apparent visual magnitude of 8.25 this was the brightest star observed by the Kepler spacecraft to host a validated planet until the discovery of an exoplanet orbiting HD 212657 in 2018. This system is located at a distance of from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −18.2 km/s.
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Kepler-21, also known as HD 179070, is a star with a closely orbiting exoplanet in the northern constellation of Lyra. At an apparent visual magnitude of 8.25 this was the brightest star observed by the Kepler spacecraft to host a validated planet until the discovery of an exoplanet orbiting HD 212657 in 2018. This system is located at a distance of from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −18.2 km/s.
thumb|left|The size of HD 179070 (right) compared to the Sun (left) The spectrum of HD 179070 presents as an evolving F-type subgiant star with a stellar classification of F6 IV. This suggests the star has exhausted the supply of hydrogen at its core and is evolving into a giant star. It is an estimated 2.6 billion years old and is spinning with a rotation period of 12.6 days. With 1.4 times the mass of the Sun it currently has 1.9 times the Sun's radius. The star is radiating five times the luminosity of the Sun from its photosphere at an effective temperature of 6,305 K.