The spectral luminosity class of the star Spica is B1 V, and that of the star $ \tau $ Ceti is G8 V. From this information, one knows that Ceti is _____ Spica.
A) cooler but has the same luminosity as
B) cooler and has a lower luminosity than
C) hotter but has the same luminosity as
D) hotter and has a lower luminosity than

Question

The spectral luminosity class of the star Spica is B1 V, and that of the star  $ \tau $ Ceti is G8 V. From this information, one knows that Ceti is _____ Spica.
A) cooler but has the same luminosity as
B) cooler and has a lower luminosity than
C) hotter but has the same luminosity as
D) hotter and has a lower luminosity than

Quizplus · Accepted Answer

The spectral type indicates both temperature and luminosity class. B-type stars like Spica are much hotter than G-type stars like Ceti. The Roman numeral V indicates both are main-sequence stars, but due to the temperature difference, Spica is both hotter and more luminous than Ceti.

The Spectral Luminosity Class of the Star Spica Is B1 τ \tau τ

The Spectral Luminosity Class of the Star Spica Is B1 $\tau$