UU Aurigae, Struve 147 & Struve 940 -- Multiple Stars in Auriga
Carbon Star & Three Multiple Star Systems in the Charioteer
The constellation of Auriga (the Charioteer) was directly over my house. The two-degree
field-of-view in the eyepiece showed two double-star systems and one triple star system. One
of the double-star systems had a bright red Carbon Star (UU Aurigae) as its brightest member.
Carbon Stars are unique in that their atmospheres contain more carbon than oxygen – not so in
other stars. The carbon combines with the oxygen, forming carbon monoxide, which consumes
all the available oxygen in the star’s upper atmosphere. The leftover carbon atoms bond with
other elements causing the star to shine ruby-red in color. No stars are darker-red than Carbon
Even with a bright gibbous moon in the sky, the star field was stunning around UU Aurigae
extending clear across the eyepiece. Unfortunately, clouds were slowly moving in rendering the sky
unfit for additional viewing. Shutting down the telescope earlier than planned is never ideal, but at
least I ended on a pleasing view in the telescope.