Area x T 4 . A certain star has exactly the same spectrum as the sun but is 30 magnitudes fainter in apparent magnitude. List some conclusions you would draw about it and describe your reasoning. The most prominent lines in its spectra will be neutral hydrogen and ionized calcium. The spectral lines of metals, such as calcium, are prominent in the solar spectrum.
Hydrogen lines are less prominent.
The sun is composed mostly of hydrogen, but at surface temperatures of 5500 K, it's not hot enough to excite hydrogen's electron to the necessary energy levels to produce prominent spectral lines.