(γ Dra / γ Draconis) is a star
in the constellation
. It has the traditional
Eltanin is an orange giant
of spectral type
K5, lying 148 light years
away. Despite its Bayer designation
of "gamma," it is
actually the brightest star in Draco, outshining Rastaban (Beta Draconis
) by nearly half a magnitude. In
fact, the name "Rastaban" was formerly used for Eltanin, and the
two terms share an Arabic
meaning "serpent" or "dragon." Its proximity to the point
directly overhead of London has also
earned it the name "Zenith Star."
In 1.5 million years, Eltanin will pass within 28 light years of
Earth. At this point it will be the brightest star in the night
sky, nearly as bright as Sirius
current absolute magnitude does not change).
In 1728, while unsuccessfully attempting to measure the parallax
of this star, James Bradley
discovered the aberration of light
resulting from the
movement of the Earth. Bradley's discovery proved Copernicus' theory
that the Earth revolved around the Sun.
Kaler, Jim (2004). "STARS: Eltanin"
. Retrieved July 11, 2005.