Exam 13: Taking the Measure of Stars

Star X and star Y are 5 AU apart from each other.Star X is four times as massive as star Y.The center of mass of this system is ________ AU away from star X and ________ AU away from star Y.

What is the difference between an eclipsing binary system and a spectroscopic binary system?

In a binary star system that contains stars with 2M_SUN and 1M_SUN, the velocity of the 2M_SUN star will be ________ times the velocity of the 1M_SUN star.

Star A is a red star.Star B is a blue star.You are able to determine that both stars are the same size.Which star appears brighter in your sky?

What is the difference between apparent brightness and luminosity?

The faster-moving star in a binary is the

How is the unit of length known as a parsec defined?

The stars that have the largest radii are classified as

When astronomers refer to "heavy elements," which elements are they talking about?

The figure below shows an H-R diagram, with five stars labeled A through E.Which star has the highest luminosity?

Suppose you observe the visual binary pair Alpha Cen A and Alpha Cen B, as seen in the figure shown below.Assuming that it can be observed repeatedly over a period of time and we know the inclination of the orbits relative to our view, what two orbital parameters can be measured from the image?

You observe a binary star system and find that star 1 has a velocity of 10 m/s while star 2 has a velocity of 35 m/s.What is the ratio of masses of the two stars (M₁/M₂)?

Main-sequence stars range in mass from approximately

The figure below shows the light curve of an eclipsing binary system consisting of two main-sequence stars.The dip in observed light is stronger when the cooler star passes in front of the hotter star than when the cooler star is behind the hotter star.Why?

A type G star is always ________ when compared to a type A star.

The fraction of the Sun's mass that is made of heavy elements is

What are the two main chemical elements that make up the Sun? How much of the mass of the Sun is composed of elements other than these two?

Spectroscopic parallax refers to

If the Hubble Space Telescope can see stars as faint as magnitude 30, how much fainter are these stars than the faintest ones you can see in a very dark night sky, which have magnitude 6?

If you want to use an Earth-based telescope to measure the distance to a star via measuring its parallax, how far apart should your observations of the star ideally be, and why?