HD 20782
Encyclopedia
HD 20782 is a 7th magnitude
G-type main sequence star
about 117 light-year
s away in the constellation
of Fornax
. HD 20782 is a part of a wide binary system with HD 20781, both stars host a planetary system. This is the first known case of planetary systems around both stars, the primary and sencodary in the binary system. The companion is HD 20781. It has a very large angular separation of 252 arcsec, corresponding to 9080 AU at the distance of HD 20782.It is estimated to be 7.1 (± 4) billion years old, with a mass close to that of our Sun
. An extrasolar planet
was announced around the primary star HD 20782 in 2006. And in 2011 two low mass planets was annonced around the secondary star HD 20781.
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
G-type main sequence star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
about 117 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s away in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
of Fornax
Fornax
Fornax is a constellation in the southern sky. Its name is Latin for furnace. It was created in the 18th century and is now one of the 88 modern constellations.-History:Fornax was formed by Nicolas Louis de Lacaille in 1756...
. HD 20782 is a part of a wide binary system with HD 20781, both stars host a planetary system. This is the first known case of planetary systems around both stars, the primary and sencodary in the binary system. The companion is HD 20781. It has a very large angular separation of 252 arcsec, corresponding to 9080 AU at the distance of HD 20782.It is estimated to be 7.1 (± 4) billion years old, with a mass close to that of our Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
. An extrasolar planet
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
was announced around the primary star HD 20782 in 2006. And in 2011 two low mass planets was annonced around the secondary star HD 20781.