Gliese 420
Encyclopedia
Gliese 420 is a binary star system located at a distance
Distance measures (cosmology)
Distance measures are used in physical cosmology to give a natural notion of the distance between two objects or events in the universe. They are often used to tie some observable quantity to another quantity that is not directly...

 of 47.9 ly light Years found in the night sky
Night sky
The term night sky refers to the sky as seen at night. The term is usually associated with astronomy, with reference to views of celestial bodies such as stars, the Moon, and planets that become visible on a clear night after the Sun has set. Natural light sources in a night sky include moonlight,...

 at RA
Right ascension
Right ascension is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination.-Explanation:...

 11h 15m 12s and dec
Declination
In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and...

 +73° 28′ 31″ 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 Draco
Draco (constellation)
Draco is a constellation in the far northern sky. Its name is Latin for dragon. Draco is circumpolar for many observers in the northern hemisphere...

.

The system comprises two 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...

s, Gl 420 A, and the smaller Gl 420 B. The two stars have a combined absolute magnitude
Absolute magnitude
Absolute magnitude is the measure of a celestial object's intrinsic brightness. it is also the apparent magnitude a star would have if it were 32.6 light years away from Earth...

 of 8.06 and an apparent magnitude
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...

 of 7.26, and a total Proper Motion
Proper motion
The proper motion of a star is its angular change in position over time as seen from the center of mass of the solar system. It is measured in seconds of arc per year, arcsec/yr, where 3600 arcseconds equal one degree. This contrasts with radial velocity, which is the time rate of change in...

 of 0.417 "/yr
Year
A year is the orbital period of the Earth moving around the Sun. For an observer on Earth, this corresponds to the period it takes the Sun to complete one course throughout the zodiac along the ecliptic....

 when viewed from earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

.

The primary star is a K5 V class
Star class
Star class could refer to:* Star-class sailboats raced in the Summer Olympic Games since 1932* GWR star-class locomotives from the 19th century.* GWR 4000 class locomotives from the early 20th century.* Stellar classification...

 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...

 with a surface temperature of 3500-5000K, a Luminosity of 5.54713e+25 and no known Planets
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...

. This star has an individual absolute magnitude of 6.846 and is also known as HD
Henry Draper Catalogue
The Henry Draper Catalogue is an astronomical star catalogue published between 1918 and 1924, giving spectroscopic classifications for 225,300 stars; it was later expanded by the Henry Draper Extension , published between 1925 and 1936, which gave classifications for 46,850 more stars, and by the...

 97584, HIP-54952, BD+
Durchmusterung
In astronomy, Durchmusterung or Bonner Durchmusterung , is the usual name for three comprehensive astrometric star catalogues of the whole sky, processed by the Bonn Observatory from 1859 to 1903....

 +74° 456, YPC: 2611.00, Vys: 603A and cd -51 12998.

The smaller secondary star (Gl 420 B) is a M0.5
Red dwarf
According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool star, of the main sequence, either late K or M spectral type....

 class
Star class
Star class could refer to:* Star-class sailboats raced in the Summer Olympic Games since 1932* GWR star-class locomotives from the 19th century.* GWR 4000 class locomotives from the early 20th century.* Stellar classification...

 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...

and is alternatively designated BD +74° 456, YPC:2611.00, Vys 603B and ADS 8100C. http://www.ari.uni-heidelberg.de/datenbanken/aricns/cnspages/4c00856.htm
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