The star named Circini has the spectral type and luminosity class of O 8.5 V. Based on this information, which of the following are true I.Circini has a surface temperature less than the Sun.
II.Circini has a diameter that is greater than that of the Sun.
III.Circini is more luminous than the Sun.
IV.Circini is located near the upper left-hand corner in the H-R diagram.

Question

Quizplus · Accepted Answer

I. False - O-type stars have very high surface temperatures, much greater than that of the Sun.
II. True - O 8.5 V stars have a diameter that is much greater than that of the Sun.
III. True - O 8.5 V stars are much more luminous than the Sun.
IV. True - O 8.5 V stars are located near the upper left-hand corner in the H-R diagram, which represents the hottest and most luminous stars.

The Star Named Circini Has the Spectral Type and Luminosity