79 Ceti
Encyclopedia
79 Ceti is a yellow subgiant
star
approximately 127 light-year
s away in the constellation
Cetus
. It has stopped hydrogen
fusion
in its core, this implies an age much higher than our Sun's 4.5 billion
years. Eventually the outer layers of the star will expand and cool and the star will become a red giant
. Currently 79 Ceti has a luminosity twice that of the Sun.
, designated 79 Ceti b
, is known to orbit 79 Ceti.
Subgiant star
A subgiant star is a star that is slightly brighter than a normal main-sequence star of the same spectral class, but not as bright as true giant stars...
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...
approximately 127 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....
Cetus
Cetus
Cetus is a constellation. Its name refers to Cetus, a sea monster in Greek mythology, although it is often called 'the whale' today. Cetus is located in the region of the sky that contains other water-related constellations such as Aquarius, Pisces, and Eridanus.-Ecliptic:Although Cetus is not...
. It has stopped hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
fusion
Nuclear fusion
Nuclear fusion is the process by which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. This is usually accompanied by the release or absorption of large quantities of energy...
in its core, this implies an age much higher than our Sun's 4.5 billion
1000000000 (number)
1,000,000,000 is the natural number following 999,999,999 and preceding 1,000,000,001.In scientific notation, it is written as 109....
years. Eventually the outer layers of the star will expand and cool and the star will become a red giant
Red giant
A red giant is a luminous giant star of low or intermediate mass in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius immense and the surface temperature low, somewhere from 5,000 K and lower...
. Currently 79 Ceti has a luminosity twice that of the Sun.
Planetary system
As of 2000, an extrasolar planetExtrasolar 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...
, designated 79 Ceti b
79 Ceti b
79 Ceti b is an extrasolar planet orbiting its star every 75 days. With HD 46375 b on March 29, 2000, it was the joint first known extrasolar planet to have minimum mass less than the mass of Saturn.-External links:...
, is known to orbit 79 Ceti.