W Orionis (Carbon Star) & Struve 630 (Double Star) in Orion
A Carbon Star & Double Star in Orion
The telescope and I are ready but the moon is taking too long to slip below the horizon. The
annoying moonlight is still flooding the sky. Double Stars and Carbon Stars are little affected
by additional sky glow, so to pass the time I turned the telescope to “W Orionis” a deep red
Carbon Star in western Orion.
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
The Double Star “Struve 630” was less than a degree away from the Carbon Star. They made a
nice match in the eyepiece and helped pass the time before moon set.