Properties of the Stars

---

Human beings have watched the stars for thousands of years. They noticed their different luminosities, reported their positions and named them. Many of the star names have Arabic origins. One of my favorite star names has got to be Zubeneschamali. Fainter stars tend to get mere catalog designations as in the Bayer greek lettering system, or the Flamsteed numbering system. Can you have a star named for you? Certainly not! Those star naming companies are a fraud.

    There are objects in the sky that are not single stars but rather clusters of stars or clouds of gas. Over 200 years ago, Charles Messier made a catalog of these objects. The cataloging of stars reached its peak about one hundred years ago or so. One of the most prominent catalogs of the early twentieth century was the Henry Draper Catalog. In this PBS program, Professor Vance of Eastern Michigan University explains the utility of star charts. But aside from these simple measurements very little was known about the stars.

    Just over one hundred years ago, scientists were beginning to understand what stars really are. Annie Cannon helped developed a stellar classification system, which has given us seven spectral types. Here are some of the basic measurements we make of stars:

• Spectral Type of stars.
• Apparent and Absolute magnitudes of stars.
• Distances to the stars, measured in light years or parsecs.
• Stellar Parallax of the stars
• Radial velocity of the stars
• Proper motion of the stars. Stars actually drift through space. The Big Dipper has not always looked the same in our skies.

    How faint of a star could you see with the unaided eye? It depends on where you live. Hiparchus set up a system over two thousand years ago.

    Here's what the Bad Astronomer has to say about proper motion.

    There are a number of different ways that one could find the distance to a particular star. Because of our orbital motion, we see an effect called parallax. Would you like to find out just about everything there is to know about determining stellar distances? Try here.     When we study the stars, we find out that the stars near the Sun are fairly faint and insignificant, for the most part. Barnard's Star is a good example of these Red Dwarfs.

Looking for a particular star? Find it here!

    Here is, what I hope will be, a useful power point presentation on the basic properties of stars.

Designed and maintained by . .
Updated January 25, 2010