The star Sirius B is classified as a _____________.

• white dwarf
• main sequence
• red giant
• super giant

Quadrant ______ includes the dimmest and hottest stars.

• 1
• 2
• 3
• 4

Two students reading the HR-Diagram were asked to identify a group of stars that have a luminosity of 105 and belong in spectral class K. Student A: The group of stars described are the White Dwarfs. Student B: The group of stars described are the Supergiants. 3. Which student is correct?

• Student 1
• Student 2
• Both students
• Neither student is correct

Two students reading the HR-Diagram were asked to identify a group of stars that have a luminosity of 105 and belong in spectral class K.

Student A: The group of stars described are the White Dwarfs.

Student B: The group of stars described are the Supergiants.

Which evidence supports the answer to this question?

• White dwarfs are in the bottom left quadrant of the HR-Diagram where the luminosity is high.
• Supergiants are in the top right quadrant of the HR-Diagram where the luminosity is high.
• White Dwarfs and Supergiants span over the spectral class G through M.
• Supergiants are in the top right quadrant of the HR-Diagram where the luminosity is low.

Using the HR-Diagram, which two statements are correct?

• A. Canopus is a main sequence star with a high luminosity and a temperature of 6,000K.
• B. Regulus is a main sequence star with a temperature of 20,000K.
• C. Antares and Betelgeuse are both red giant stars.
• D. Sirius and Capella are main sequence stars with a luminosity similar to the Sun.
• E. Mira is a red giant star with a temperature of 3,000K.

White dwarfs have a _______ luminosity.

• high
• low

Some of the white dwarf stars belong in spectral class ______.

• K
• M
• A

Using the HR-Diagram, which two statements are correct?

• A. White dwarfs have a high luminosity and range in temperature from 40,000 to 20,000K.
• B. The main sequence stars include the widest range of temperature on the HR Diagram.
• C. Blue giants and Red super giants have the highest luminosity on the HR-Diagram.
• D. White dwarfs and Red giants have a similar luminosity range.
• E. Blue giants tend to be dim and hot stars.

This star has a luminosity of 10^4 and is in spectral class O.

• Main Sequence
• White Dwarfs
• Giants
• Supergiants

This star has a luminosity of 10^-3 and is in spectral class M.

• Main Sequence
• White Dwarfs
• Giants
• Supergiants