Beta Gruis
Encyclopedia
Beta Gruis is the second brighest star
in the southern constellation
of Grus
. It was once considered the rear star in the tail of the constellation of the (Southern) Fish
: it, with α
, δ, θ. ι, and λ Gru, belonged to Piscis Austrinus
in traditional Arabic astronomy.
The estimated mass is about three times that of the Sun
, and it has a surface temperature of approximately 3,400 K
, just over half the surface temperature of the sun. This low temperature accounts for the star's dull red color. The total luminosity is about 3,800 times that of the Sun, and it has an estimated radius of 0.8 AU, which is about 100 times that of the Sun.
Beta Gruis is a type LC slow irregular variable
star that varies in magnitude from 2.0 to 2.3.
Beta Gruis played a crucial part in Perth Observatory
's tracking of comet 2000 WM1 LINEAR in December 2001.
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...
in the southern 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 Grus
Grus (constellation)
Grus is a constellation in the southern sky. Its name is Latin for the crane, a species of bird. It was introduced in the late sixteenth century.-History:The stars that form Grus were originally considered part of Piscis Austrinus...
. It was once considered the rear star in the tail of the constellation of the (Southern) Fish
Piscis Austrinus
Piscis Austrinus is a constellation in the southern celestial hemisphere. The name is Latin for "the southern fish" in contrast with the larger constellation Pisces, which represents a pair of fishes. Prior to the 20th century, it was also known as Piscis Notius...
: it, with α
Alpha Gruis
Alpha Gruis is the brightest star in the constellation Grus.Alpha Gruis has a proper name Alnair or Al Nair , came from the Arabic al-nayyir [an-nai:r], meaning "the bright one"...
, δ, θ. ι, and λ Gru, belonged to Piscis Austrinus
Piscis Austrinus
Piscis Austrinus is a constellation in the southern celestial hemisphere. The name is Latin for "the southern fish" in contrast with the larger constellation Pisces, which represents a pair of fishes. Prior to the 20th century, it was also known as Piscis Notius...
in traditional Arabic astronomy.
The estimated mass is about three times that of the 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...
, and it has a surface temperature of approximately 3,400 K
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
, just over half the surface temperature of the sun. This low temperature accounts for the star's dull red color. The total luminosity is about 3,800 times that of the Sun, and it has an estimated radius of 0.8 AU, which is about 100 times that of the Sun.
Beta Gruis is a type LC slow irregular variable
Slow irregular variable
A slow irregular variable is a variable star that exhibit no or very poorly defined periodicity in their slowly changing light emissions. Most of them are late spectral types K and M, S stars or carbon stars...
star that varies in magnitude from 2.0 to 2.3.
Beta Gruis played a crucial part in Perth Observatory
Perth Observatory
The Perth Observatory is the name of two astronomical observatories located in Western Australia.-First Perth Observatory:The original Perth Observatory was constructed in 1896 and was officially opened in 1900 by John Forrest, the first premier of Western Australia. The observatory was located at...
's tracking of comet 2000 WM1 LINEAR in December 2001.
External links
- Stars of the week article
- MSN Encarta (Archived 2009-10-31)