Superstar Challenges Theory

A new record holder has been found for biggest star: LBV 1806-20 in Sagittarius.  According to the NewsNotes entry on p. 20 of the April 2004 issue of Sky and Telescope, the star is up to 3 times hotter than the surface of our sun, and has a diameter 200 times as big.
    Most interesting is the star’s mass, estimated to be “150 solar masses — perhaps more.  That ought to make stellar theorists sit up and take notice.  No star can survive with more than about 100 or 120 solar masses, according to well-established theory.”

Theories, like Olympic records, are made to be broken.  Let facts be true, and every theory a liar.
    The news item on the next page, “Getting to Know Our Stellar Neighbors,” reports results of a survey of all the stars within 10 parsecs (about 32.6 light-years) of our sun.  Surprisingly, small red dwarfs rule, nearly 12 times more numerous than stars like our sun.  This provides more evidence against the belief that Earth orbits an ordinary star.  Also, the habitable zone around a red dwarf is much narrower, lowering the probability life could exist around such a star.  The astronomer doing the survey, Todd Henry, believes the constraint is balanced by the sheer numbers of red dwarfs, but what is the chance an earthlike planet would be found in a circular orbit within such a narrow ring, when even around our sun the habitable zone represents a small fraction of the radius of our solar system?  One might almost suspect our location, at just the right distance around the right kind of star, was intelligently designed (see next headline).