The stars in the sky when you look up at night Appear at first glance to be pinpoints of light. But study them closely. They're not all alike. Oh, be a fine girl, kiss me. The hot stars are blue and the cool ones are red. Yes, color tells temperature; that's what I said. Some stars are still living, and some are long dead. Oh, be a fine girl, kiss me.
The hottest blue stars we consider Type O. The cool ones are M Class. Confusing, I know. The system was standardized quite long ago. Oh, be a fine girl, kiss me.
Look up in the daytime, and what do you see? Our warm yellow Sun, which we know is Class G. A star like the others, but special to me... Oh, be a fine girl, kiss me.
As Hurtzprung and Russell said time after time, The main sequence stars queue up in a straight line. Their blackbody curves tell you every star's kind. Oh, be a fine girl, kiss me.
The stars clump together, not by twos or threes, But hundreds of billions, to form galaxies, And there are a good hundred billion of these. Oh, be a fine girl, kiss me.
Today's population of stars we call I. A nearby example would be our own Sun. They're quite rich in metals, and tend to be young. Oh, be a fine girl, kiss me.
The first population of stars we call II. Just fusion reactors, and what did they do? Produce heavy elements, planets, and you. Oh, be a fine girl, kiss me.
In five billion years, our Sun's life will draw short; We can't say exactly its ultimate course. Expand to red giant, or shrink to white dwarf? Oh, be a fine girl, kiss me.
I've studied the stars of each possible kind. I'm happy to watch them for quite a long time. And don't you just love how they twinkle and shine? Oh, be a fine girl, kiss me.