Noteworthy Astronomical Websites - 1

Noteworthy Astronomical Websites - 1

The reddest of the red stars
http://www.astroscience.org/abdul-ahad/ruby-star.htm

The author of this site, A Ahad, identifies CE TAU as the second
reddest star in the sky that consistently remains at magnitude 5 or
above.

However I am not clear as to the significance of the "Magnitude Colour
Index Optimisation Curve" - particularly as to why the curve has been
placed where it has on the supplied graph or indeed how this curve
adds to the debate at all.

Can somebody explain please?

Martin Nicholson, Daventry, England.
http://www.martin-nicholson.info/1/1a.htm

Visit the Astronomical Hall of Shame at http://www.geocities.com/queen5658/