February's Star is Procyon

This month look for the star Procyon. Procyon is the lucida of the constellation of Canis Minor, the Little Dog. It’s located in the southeast and to the upper left of Sirius, the brightest star in the skies. If you were born in 2002 then Procyon is your birthday star this year because the light of Procyon you see tonight left the star 11.4 years ago. The name Procyon comes from the Greek meaning, Before the Dog. This name is in reference to the fact that Procyon rises shortly before Sirius, the Dog Star, for mid-latitudes. Companion stars orbit both Procyon and Sirius and both companion stars are white dwarfs.

White dwarfs are aged stars that have consumed their supply of nuclear fuel of hydrogen and helium. Without the energy released from the fusion of hydrogen to support their weight, gravity compresses the stars into spheres the size of planets (about 100 times smaller that they use to be). A cubic centimeter of their compressed matter weighs about a ton. Imagine the weight of a car in a single teaspoon. White dwarf stars consist primarily of the carbon ash left behind from their glory days. With enough pressure, carbon atoms link up into a crystalline form know as diamond. Therefore, it’s possible that many white dwarf stars are giant diamonds in the sky.

Physicists call the matter of white dwarves degenerate. It’s only the reluctance of electrons to be squeezed into one another that keeps these stars from collapsing further. However, if you add more mass to white dwarfs, they would “burn the ash” in their cores into even heavier elements like silicon and iron, and then end their lives as stars collapsed into even smaller objects like neutron stars and black holes. Over billions of years, white dwarfs cool from white, to yellow, then to orange, red, and finally to black. Probably no white dwarf in the universe has had enough time to cool to a black dwarf.