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Stars and the Origin of the Universe — Test Answers

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1
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Which method is most appropriate for measuring the distance to a star cluster located 50,000 light-years away in the Milky Way?

A
type Ia supernovae
B
Cepheid variables
C
parallax
D
redshift
4
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Assume that scientists have discovered a galaxy where iron was more abundant than helium. What is the best conclusion regarding the galaxy's history?

A
The galaxy has never experienced any changes in element composition.
B
The galaxy formed before the Big Bang.
C
The galaxy is exceptionally young and just formed.
D
The galaxy has undergone extensive star formation and supernova explosions.
5

What does the data suggest about the motion of each star?

A
Star X is moving away from Earth, while Star Z is moving toward Earth.
B
Star Y is moving toward Earth, while Star Z is stationary.
C
Star X and Star Y are both moving away from Earth.
D
Star X is moving toward Earth, while Star Z is moving away from Earth.
8

Use the data to match each galaxy's distance from Earth with its expected velocity.

Answer:

13,200 km/s|4,400 km/s|26,400 km/s

9

Calculate the approximate distance for Galaxy B, rounded to the nearest whole number.

Answer:

43

10

What does this data reveal about the relationship between redshift and the scale of the universe?

A
Hubble's Law suggests all galaxies in the universe remain at fixed distances from one another.
B
Galaxies with higher redshift move away faster, supporting the idea that the universe is expanding.
C
The galaxies with lower redshift are the farthest, meaning the universe is contracting.
D
The velocity of galaxies is random, showing no apparent relationship to their distance.
11

Choose the correct answer from each drop-down menu to complete the statement.

Answer:

arranged in patterns|at various distances from Earth|continue to form far away

12

Scientists discovered a star in a distant galaxy that is currently 5.0M_☉ and has been on the main sequence for 50 million years. Choose the correct answer from each drop-down menu to complete the statement.

Answer:

50|white dwarf

13

Redshifts were used as supporting evidence for the big bang theory. Which describes redshifts? Choose three correct answers.

A
They indicate receding galaxies.
B
The light source and observer move farther apart.
C
Observed light shifts to a shorter wavelength.
D
They indicate approaching galaxies.
E
The light source and observer move closer together.
F
Observed light shifts to a longer wavelength.
14

Two stars, Star X and Star Y, have the same radius, but Star X is twice as hot as Star Y. Based on the Stefan-Boltzmann Law, what can be said about their luminosities?

A
Star X is four times as luminous as Star Y.
B
Star X is eight times as luminous as Star Y.
C
Star X is twice as luminous as Star Y.
D
Star X is sixteen times as luminous as Star Y.
15

Match each stellar remnant with its corresponding mass range.

Answer:

8–25 solar masses|more than 25 solar masses|less than 8 solar masses

16

Astronomers measure the brightness and spectral type of a star to estimate its distance. The inverse square law states that a star's apparent brightness (B) decreases with the square of its distance (d) : B∝(1)/(d^2) A G-type star has an absolute brightness of 10units If it appears to have an apparent brightness of 2.5units , what is its estimated distance using spectral parallax?

Answer:

2

17

According to the big bang theory, which describes the universe before the actual big bang occurred?

A
multiple, hot, dense points, each smaller than an atom
B
multiple, cold, dense points, each larger than the Sun
C
single, cold, dense point larger than the Sun
D
single, hot, dense point smaller than an atom
19

Which best describes cosmic microwave background radiation?

A
radiation that existed before the big bang
B
radiation predicted to exist in millions of years
C
radiation thought to exist but not yet measured
D
leftover radiation from the big bang
20

When an exoplanet transits a star, additional absorption lines appear at wavelengths associated with methane (CH_4) and water vapor (H_2O) What can scientists infer based on the additional absorption lines?

A
The exoplanet is moving away from Earth, creating a Doppler shift.
B
The star's atmosphere contains methane and water vapor.
C
The star is producing methane and water vapor as a result of fusion.
D
The exoplanet's atmosphere contains methane and water vapor.
21

A team of astronomers has detected a massive explosion in a nearby galaxy. Their observations show that the exploded star was originally around 25 solar masses. Arrange the events that led to the explosion in the order they occurred.

Answer not available
23

What is luminosity?

A
the amount of energy a star emits in a unit of time
B
the average temperature of a star during its life cycle
C
the degree of shift toward the red end of the spectrum
D
the brightness of a star as seen from Earth
24

Astronomers study the spectrum of a distant star and observe strong absorption lines at 1.4µm (water vapor) and 2.3µm (methane). What can they conclude about this star?

A
The star is fusing hydrogen into helium.
B
The star is primarily composed of hydrogen.
C
The star's atmosphere contains water vapor and methane.
D
The star's atmosphere is too hot for other molecules to exist.

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