Auriga
The constellation of Auriga is easy to find using the
Plough as a signpost. From Megrez, the faintest of the Plough’s
seven stars, draw a line through Dubhe, the top pointer and extend it
until you get to a bright yellow star shining above the eastern horizon
early on winter evenings. This is Capella, Auriga’s lead star (if
you get to the Pleiades you have gone too far). Capella, 46 light years
from Earth, is the most northerly first magnitude star and is circumpolar
from our latitude. It is the sixth brightest star in the sky and in fact
is a multiple system consisting of at least four members. Since the earliest
times Auriga has been identified with a charioteer carrying a she-goat
& her kids.M37, NGC 2099, Open Cluster
M37, NGC 2099, Open Cluster
Capella is also known as the “Goat Star”.
Auriga is often overlooked
amongst the fine winter constellations of Orion’s
retinue, but it does contain a number of excellent objects for binoculars
or small telescopes. Chief of these are the three open clusters from Charles
Messier’s famous catalogue, M36, 37 & 38. Of these, M37 is a
particularly fine object.
Finally before leaving Auriga, take a look at the three
fainter stars close to Auriga. These are known the “Kids”.
Epsilon, the closest of the three to Capella is an extraordinary system.
It has the longest known period of any eclipsing binary. The main star
is an extremely luminous white supergiant. It is about 2,000 light years
away and normally shines at magnitude 3.0. Every 27 years though, it gradually
drops to magnitude 3.8 over a fourth month period, remaining at that magnitude
for 14 months before returning to normal. The next event commences in
2009. The nature of the object causing the eclipses was a mystery to astronomers
for a long time. It is now thought to be a close pair of stars surrounded
by a huge disk of dust.
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