AN Ursae Majoris
Encyclopedia
AN Ursae Majoris is a variable star
in the constellation
Ursa Major
. This star has the strongest known magnetic field
among cataclysmic variables , with a field strength of 230 million gauss (23 kT). This object, along with AM Herculis
, define a class of objects known as polars
.
Variable star
A star is classified as variable if its apparent magnitude as seen from Earth changes over time, whether the changes are due to variations in the star's actual luminosity, or to variations in the amount of the star's light that is blocked from reaching Earth...
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....
Ursa Major
Ursa Major
Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April...
. This star has the strongest known magnetic field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
among cataclysmic variables , with a field strength of 230 million gauss (23 kT). This object, along with AM Herculis
AM Herculis
AM Herculis is a red dwarf variable star located in the constellation Hercules. This star, along with the star AN Ursae Majoris, is the prototype for a category of cataclysmic variable stars called polars, or AM Her type stars.-History:...
, define a class of objects known as polars
Polar (cataclysmic variable)
A Polar is a type of cataclysmic variable binary star system with a very strong magnetic field.In most cataclysmic variables, matter from a main-sequence companion star is gravitationally stripped by a white dwarf star in the form of an accretion disk. In polar systems, the magnetic field of the...
.