Astro 150 - Exam 2 Review

What is the order of layers in the sun?

• Core, photosphere, convective zone, radiative zone

• Core, radiative zone, convective zone, photosphere

• Core, convective zone, radiative zone, photosphere

• Core, convective zone, photosphere, radiative zone

At which part of the sun do sunspots exist?

• Convective zone

• Chromosphere

• Photosphere

• Corona

Where does the energy in hydrogen fusion come from?

• Atoms that combine with each other suddenly slow down, releasing a lot of heat

• The combined mass of the reactants is greater than that of the products, and that extra mass is converted to energy

• The hydrogen atoms catch on fire and melt into each other to make helium atoms

• Helium atoms quickly slough energy upon formation because helium is a noble gas

A star has a parallax of 0.1 arcseconds. How far away is the star?

• 10 lightyears

• 10 parsecs

• 50 lightyears

• 50 parsecs

What is a star's proper motion?

• How fast the star is moving away from us

• The combined motion of the star away from us and across our view

• How fast a star is moving spatially once you've factored in the motion of the sun

• How fast a star is moving across our view

What is something the Doppler shift CAN'T help us find?

• It helps us see how fast a star is moving across our view

• It helps us see how fast a star is rotating

• It helps us see how fast a star is moving toward us or away from us

• How fast binary stars are orbiting the center of mass

Why might a white dwarf have a much lower luminosity than a red giant?

• Red giants are extremely large

• Most white dwarfs are much farther away from us than red giants

• White dwarfs aren't really all that hot

• White dwarfs tend to have a greater luminosity than red giants

• 0.73x hotter

• 1.37x hotter

• 1.64x hotter

• There is not enough information!

What is the correct order for each region of this HR diagram? (A,B,C)

• Main Sequence, Red Giants, White Dwarfs

• Red Giants, Main Sequence, White Dwarfs

• Main Sequence, White Dwarfs, Red Giants

• Red Giants, White Dwarfs, Main Sequence

What are the four types of binary stars?

Answer explanation

Visual, Spectroscopic, Eclipsing, Eclipsing Spectroscopic