# Wright State University Lake Campus/2016-1/Phy1060/T1 upgrade

Test 1 study guide (pdf)      mirror

So far here are the subpages that have been created. Your's will appear here when you create the page. Use these subpages to document where you have contributed. As you report, refer to the the question number. The first edit by user:Guy vandegriftSock1 was to note that the question mark was missing on problem 4.

### 1

Stellar parallax is

Luminosity is

### 3

A standard candle is

### 4

Absolute magnitude is

### 5

Relative magnitude is

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In 1989 the satellite Hipparcos was launched primarily for obtaining parallaxes and proper motions allowing measurements of stellar parallax for stars up to about 500 parsecs away, which is about ____ times the diameter of the Milky Way Galaxy.

### 7

An object emits thermal (blackbody) radiation with a peak wavelength of 250nm. How does its temperature compare with the Sun?

### 8

The "normalized intensity" of a Sun-like star situated one parsec from Earth would be 4πI = 1. What is 4πI for a star with 100 times the Sun's energy output that is situated 10pc from Earth?

### 9

An orbiting satellite makes a circular orbit 5 AU from the Sun. It measures a parallax angle of 0.2 of an arcsecond (each way from the average position). What is the star's distance?

### 10

A star that is increasing it's temperature while maintaining constant luminosity is

### 11

The range of wavelength for visible light is between

### 12

Based on the HR diagrams and images in stars shown in the materials, a very large red supergiant has a diameter that is about ____ greater than a small white dwarf.

### 13

Why is a star made of plasma?

### 14

What is the difference between a constellation and an asterism?

### 15

Stellar parallax is

### 16

Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds.

### 17

A starburst galaxy.

### 18

Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant)

### 19

Which of the following changes in the properties of a giant molecular cloud might cause it to collapse?

### 20

What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed?

### 21

What is a Bok globule in the formation of stellar systems?

### 22

Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by

### 23

Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence.

### 24

The Hayashi and Henyey tracks refer to how T Tauri of different masses will move

### 25

How do low-mass stars change as they are born?

Birth of stars HR path tracks

### 26

When a star with more than 10 solar masses ceases fuse hydrogen to helium, it

### 27

Many supernovae begin as a shock wave in the core that was caused by

### 28

A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____

### 29

According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____

### 30

A grouping with 100 thousand stars would probably be a

### 31

A grouping with a hundred stars is probably a

### 32

I gravity is what holds stars in a cluster together, what is the most important process that causes them to spread apart?

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Members of an open cluster feel significant forces only due to gravitational interaction with each other

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Members of an open cluster feel significant forces from nearby giant molecular clouds

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Members of a globular cluster tend to be

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Members of a globular cluster tend to have

### 37

In 1917, the astronomer Harlow Shapley was able to estimate the Sun's distance from the galactic centre using

### 38

Most globular clusters that we see in the sky orbit _____ and have ______ orbits

### 39

Many stars in a typical open cluster are nearly as old as the universe

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Many stars in a typical globular cluster are nearly as old as the universe

### 41

The number of globular clusters in the Milky way galaxy is about

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The location of open clusters can be described as

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Stars can "evaporate" from a cluster. What does this mean?

### 44

At the center of the Crab nebula is

### 45

Aside from its location on the HR diagram, evidence that the white dwarf has a small radius can be found from

### 46

This spectrum of the star Vega suggests that

### 47

Which of the following is NOT an essential piece of a a strong argument that a white dwarf is not only the size of the earth, but typically has the same mass as the Sun.

### 48

The course materials presented three arguments suggesting that a white dwarf is roughly the size of the earth. Which best summarizes them?

### 49

As of 2008, the percent uncertainty in the distance to the Crab nebula is approximately,

### 50

What was Messier doing when he independently rediscovered the Crab in 1758?

### 51

What best explains this figure?

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What causes the blue glow of the Crab nebula?

### 53

One way to determine the distance to a nebula or small cluster of clouds is to compare the angular expansion to the spectroscopic Doppler shift. Two clusters (A and B) have the same spectroscopically measured velocity. Cluster A is moving towards the observer and exhibits the greater angular expansion. Which cluster is closer?

### 54

What causes the "finger-like" filamentary structure in the Crab nebula?

### 55

${\displaystyle KE={\frac {4\pi ^{2}}{5}}{\frac {MR^{2}}{P^{2}}}}$ is the kinetic energy of a solid rotating ball, where M is mass, R is radius, and P is period. And, ${\displaystyle power={\frac {energy}{time}}}$.
You are banging espressos in a little coffeehouse with your astronomy friends, talking about a new SN remnant that closely resembles the Crab. You have observed the pulsar, and wonder what the total power output of the nebula might be. You know both the period of the pulsar, as well as ${\displaystyle \tau }$, which represents the amount of time you think the pulsar will continue pulsing if it continues slowing down at its present rate. What formula do you write on your napkin?

### 56

In one respect, the universie is arguably "young", considering how much complexity it contains. This is often illustrated by a calculation of

### 57

Comparing Hubble's original (1929) plot of redshift versus distance with the later one in 2007, the latter extends farther into space by a factor of

### 58

The course materials present two cosmic expansion plots. Hubble's original (1929) plot used

### 59

The course materials present two cosmic expansion plots. The more recent (2007) plot used

### 60

Place yourself in an expanding raisinbread model of Hubble expansion. A raisin originally situated at a distance of 4 cm expands out to 12 cm. To what distance would a raisin originally situated at a distance of 2 cm expand?

### 61

You at the center raisin of an expanding raisinbread model of Hubble expansion, and from your location a raisin originally situated at a distance of 1 cm expands out to a distance of 4 cm. The nearest raisin with intelligent life is situated exactly halfway between your (central) location and the edge. How would this second "intelligent" raisin view an expansion of a raisin 1 cm away?

### 62

Place yourself in an expanding raisinbread model of Hubble expansion. A raisin originally situated at a distance of 2 cm expands out to 4 cm. To what distance would a raisin originally situated at a distance of 4 cm expand?

### 63

This light clock is associated with

### 64

Suppose the light clock involved a ball being tossed back and forth on a train going just under the speed of sound. In contrast to the situation for light reflecting back and forth on a train going just under the speed of light, there is virtually no time dilation. Why?