RT Ursae Majoris -- Carbon Star in Ursa Major
I picked the Carbon Star (Ursae Majoris) to observe to allow the sky to darken and the
telescope to adjust to the outside temperatures. This unimpressive Carbon Star was
only about a degree away from my first galaxy target of the night (NGC 2841). By the
time the drawing was done, conditions were right to start hunting galaxies.
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 Stars.