HR Diagram Review

What is the relationship between temperature and luminosity for main sequence stars?

• Higher temperatures correspond to lower luminosities.

• Higher temperatures generally correspond to higher luminosities.

• There is no relationship between temperature and luminosity.

• Luminosity is independent of temperature.

What is the H-R Diagram?

• A scatter plot of stars showing the relationship between their absolute magnitudes or luminosities versus their stellar classifications or effective temperatures.

• A diagram that represents the life cycle of stars from birth to death.

• A chart that categorizes stars based on their color and brightness only.

• A graphical representation of the distance of stars from Earth.

Which spectral class is the hottest?

• A. M

• B. K

• C. B

• D. O

How does the brightness of a star change with distance?

• The apparent brightness of a star decreases with the square of the distance from the observer.

• The brightness of a star remains constant regardless of distance.

• The brightness of a star increases linearly with distance.

• The brightness of a star decreases exponentially with distance.

What is luminosity in the context of the H-R Diagram?

• Luminosity refers to the total amount of energy emitted by a star per unit time, often measured in solar units.

• Luminosity is the brightness of a star as seen from Earth.

• Luminosity is the distance of a star from Earth.

• Luminosity is the temperature of a star's surface.

What is a white dwarf?

• A small, dense star that is the remnant of a low to medium mass star after it has exhausted its nuclear fuel.

• A large, bright star that is in the final stages of its life cycle.

• A type of planet that orbits a star in a binary system.

• A star that has exploded in a supernova and left behind a neutron star.

What type of star is Betelgeuse classified as?

• A red dwarf star

• A white dwarf star

• A red supergiant star

• A blue giant star

What is the significance of the spectral classification OBAFGKM?

• It categorizes stars based on their sizes and masses.

• It categorizes stars based on their colors and brightness.

• It categorizes stars based on their temperatures and spectral characteristics, from the hottest (O) to the coolest (M).

• It categorizes stars based on their distances from Earth.

What does a negative magnitude indicate about a star's brightness?

• A negative magnitude indicates that the star is very bright; the lower the number, the brighter the star.

• A negative magnitude indicates that the star is dim and hard to see.

• A negative magnitude has no effect on a star's brightness.

• A negative magnitude indicates that the star is average in brightness.

What does the y-axis of the H-R Diagram represent?

• Temperature of the stars

• Distance of the stars

• Luminosity (or brightness) of the stars

• Color of the stars