Auriga is a prominent constellation high
in the Northeast. It is north of Taurus,
our Jan 2014 constellation of the month, and east of Perseus,
our Dec. 2013 constellation of the month. The band of the Milky Way passes
through Auriga between Perseus to the West and Gemini
to the East.
Auriga is shaped like a pentagon, or
a child's drawing of a house. It has one
magnitude 0 star, Capella, and the other 4 are 2nd magnitude. Like so many other stars, Capella is a
multiple star. It is comprised of 4 stars, made up of 2 binary pairs which
orbit around each other. One is a pair
of bright yellow stars in the same category (G) as our Sun. They are each 10 times as large as the
Sun. This may be because they are
expanding on their way to becoming Red Giant stars, which is near the final
stage of the life of stars like the Sun.
The other two are red dwarf stars.
These are small-mass stars which are relatively cool. Red stars – like red flames on earth are
cooler than yellow stars like the Sun, which are, in turn, cooler than blue or
white stars. Being of lower mass and
cooler than other stars, they evolve more slowly and live longer than massive
blue or white stars.
Auriga is home to 3 bright open star
clusters – M36, M37, and M 38. They can
all be seen in one field of view with wide-angle binoculars. Other points of interest are two eclipsing
variable stars. These appear to vary in
brightness when viewed from the earth, because the two stars appear either
side-by-side or one in front of the other.
Other variable stars actually change their brightness by expanding and
contracting.
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