Stellar Evolution

According to the HR diagram, what is the approximate surface temperature of Alcor?

• 3,000 K

• 5,000 K

• 10,000 K

• 20,000 K

Tags

NGSS.HS-ESS1-3

Which location shows the sun, a star with average temperature and average brightness?

• A

• B

• C

• D

Most of the stars on the HR diagram (90%) are classified as

• Main sequence stars

• Supergiants

• Giants

• White dwarfs

Energy is produced in the cores of main sequence stars like our sun when

• Heavier elements undergo fusion into lighter elements

• Cosmic background radiation is absorbed

• Lighter elements undergo fusion into heavier elements

• Cosmic background radiation is released

Tags

NGSS.HS-ESS1-1

NGSS.HS-ESS1-3

Which of the following characteristics determines the color of a star?

• Luminosity

• Temperature

• Distance

• Mass

Answer explanation

Temperature determines color.

Tags

NGSS.HS-ESS1-1

HR diagrams are most useful for

• Locating stars

• Classifying stars

• Locating galaxies

• Classifying galaxies

Tags

NGSS.HS-ESS1-3

Why do high-mass stars skip the helium flash stage that low-mass stars go through before dying?

• Not enough hydrogen at the core.

• Once hydrogen is used up at the core the star explodes.

• Once helium is used up at the core the star explodes.

• High-mass stars never die.

Tags

NGSS.HS-ESS1-3

When an ______ core is reached in a high-mass star, gravity takes over.

• iron

• carbon

• oxygen

• helium

Tags

NGSS.HS-ESS1-3

When an iron core is reached gravity takes over and a(n) _________ occurs.

• black hole

• neutron star

• explosion

• supernova

Tags

NGSS.HS-ESS1-3

_____ stars evolve and move off the main-sequence first; then intermediate stars & so on.

• Low-mass

• Red giant

• High-mass

• White dwarf

Tags

NGSS.HS-ESS1-3