Classcolor
prominent spectral lines
surface temp. (k)
o
blue
ionized helium, hydrogen
> 25,000
b
blue-white
neutral helium, hydrogen
11,000 - 25,000
white
hydrogen, ionized sodium, ionized calcium
7,500 - 11,000
6,000 -- 7,500
white
hydrogen, ionized sodium and calcium; neutral
sodium and calcium
yellow
5,000 -6,000
neutral sodium and calcium, ionized calcium,
ionized iron, ionized magnesium
orange
3,500 -5,000
neutral calcium, neutral iron, neutr
magnesium
m
l
red
< 3,500
neutral iron, neutral magnesium, and neutral
titanium oxide (not shown)
use the harvard classification scheme (shown in the table above) to answer the following quesiton: the sun contains spectral
lines from neutral sodium and calcium as well as ionized calcium, magnesium and iron. of the choices below, which could be
the surface temperature of the sun?