ST401385@BROWNVM.BITNET (03/13/86)
Around '76 or so, when the Archaeoastromomy subject first came
around, I went to a lecture about it by Ken Brecher (then at MIT). He
said that (1) The Egyptians were very interested in Sirius, because they
timed the floods of the Nile by it. It seems unlikely that they would
make a mistake on its color. (2) Sirius gets quite high above the
horizon. It seems unlikely that they would happen to observe it, and it
only, at the horizon. (3) Alpha Centauri, which never gets very high
above the horizon, is not described as red.
The point of the recently discovered record of Sirius' color is that
this is a observation independent of the Egyptian observations, and it
still calls the star red.
Brecher calculated that if Sirius B were a red giant, the observed
color of the system would indeed be reddish. The problem is that if it
were a red giant only 2000 years or so ago, according to the best
present model of stellar evolution, it would not have had time to
cool off to the present temperature. Brecher argued that this is a
reason to revise the present model.
--Geoffrey Landis