Astronomy Exam 3 Question Sreview

Front 1

What is a White Dwarf?

Back 1

A dead burning core with no energy production that was once a burning star

Front 2

What is the size mass limit for a White Dwarf star?

Back 2

White Dwarf mass limit equals 1.4 solar masses (electron degeneracy), basically what's keeping it from getting smaller since two electrons cannot occupy the same space. The larger the White Dwarf mass, the smaller the White Dwarf gets packed together.

Front 3

In an H-R Diagram and star formation, you can determine....

Back 3

The temperature, the spectral class, the luminosity, and the absolute magnitude.

Front 4

What is the spectral class order of star's from hottest to coolest?

Back 4

O.B.A.F.G.K.M

Front 5

What is the Sun's luminosity rating?

Back 5

1

Front 6

Which type of star's will use up their hydrogen fuel more quickly

Back 6

High mass stars

Front 7

Which type of star's will burn brighter, consume more fuel and last less in its lifetime?

Back 7

High mass stars.

Front 8

Star's spend most of their lifetime as what?

Back 8

Star's spend 90% of their whole life as Main sequence stars.

Front 9

What is hydrostatic equilibrium?

Back 9

It's when a star's core has a balance where gravity wants to collapse the star pushing inward, but pressure pushed outward by photons from nuclear fusion on the core against the collapsing material.

Front 10

Why are all main sequence stars in hydrostatic equilibrium?

Back 10

Because nuclear fusion of hydrogen is producing enough outward pressure to balance the gravitational collapse.

Front 11

What is nuclear fusion?

Back 11

When light elements combine to make heavier elements

Front 12

How does a giant molecular cloud collapse?

Back 12

Shockwaves or pressure from nearby objects or events, supernova explosions creating shockwaves, radiation from nearby massive star's that can provide pressure, or within a cloud, some material is compressed by a shockwave and gravity further condenses.

Front 13

What are Nebulae made up of?

Back 13

Bonded hydrogen (H2). Nebulas are made up of clump gas and dust.

Front 14

What are star's formed from?

Back 14

Giant clouds of molecular gas and dust of mostly hydrogen (H2), but also duplicates and carbon (dust).

Front 15

What are the three steps to star formation?

Back 15

1. Collapse of giant molecular cloud

2. Nuclear fusion reactions in the core of the new star

3. Equilibrium between inward gravitational pressure and outward gas pressure

Front 16

In an H-R Diagram it can tell us

Back 16

Ages of stars, where in the star pattern it is in, it's evolutionary state, and determine how long a.star will last

Front 17

What are the smallest stars

Back 17

Red dwarfs that are main sequence stars that are low in temperature and low in luminosity.

Front 18

If something has a low temperature but high luminosity it must be...

Back 18

Very large in size, aka, a red giant

Front 19

If main sequence stars have the same luminosity as red giants but are cooler in temperature, then the red giants have to be...

Back 19

Bigger to make up for it

Front 20

A white dwarf star has to be very big or very small?

Back 20

Very small due to It being very hot but also low in luminosity

Front 21

What is an ISM?

Back 21

Interstellar medium: mostly hydrogen but also dust

Front 22

The brighter absolute magnitude, the lower or higher the luminosity?

Back 22

Higher the luminosity

Front 23

What does Spectral class go along with?

Back 23

Temperature

Front 24

RED Giants sre

Back 24

Really big, not very hot but very bright.

Front 25

White dwarfs are

Back 25

Very small, very hot, but not very bright

Front 26

O spectral star's are hotter than..

Back 26

25,000 kelvin

Front 27

How hot are G spectral star's and character do we know that is one?

Back 27

G spectral Stars range from 5000 to 6000 Kelvin, and an example of one is our Sun.

Front 28

In an H-R Diagram, for Absolute magnitude, the lower the number, the..

Back 28

More luminosity it has (brightness)

Front 29

In an H-R Diagram, the lower numbers across the spectral class...

Back 29

The cooler temperature it is.

Front 30

An O spectral class Starbucks be closer to what color?

Back 30

Blue

Front 31

An M spectral class star would closer to what color

Back 31

Red

Front 32

By comparing the apparent magnitude and absolute magnitude numbers, we can...

Back 32

Estimate a star's distance from Earth.

Front 33

When m = M, then the star is located...

Back 33

Exactly 10 parsecs from Earth

Front 34

When m < M, then the star appears...

Back 34

Brighter than it would be if it were 10 parsecs seat, so it must be closer than 10 parsecs from Earth.

Front 35

When m > M, then the star appears...

Back 35

Dimmer than it would if it were 10 parsecs away, so it must be farther than 10 parsecs from Earth.

Front 36

Apparent Magnitude is upper case M, or lower case m?

Back 36

Apparent magnitude is lower case m. Absolute magnitude is upper case M.

Front 37

The absolute magnitude number of a star is based on the...

Back 37

Total energy output (luminosity) of a star. How bright a star actually is.

Front 38

The absolute magnitude number is smaller or bigger for dimmer stars?

Back 38

Smaller

Front 39

The absolute magnitude number is bigger or smaller for brighter stars?

Back 39

Bigger

Front 40

The apparent magnitude number of a star is based on..

Back 40

How bright it appears on Earth

Front 41

For the apparent magnitude, the number is more negative or more positive for brighter stars?

Back 41

More negative for brighter stars (smaller numbers)

Front 42

For the apparent magnitude, the number is more negative or more positive for dimmer stars?

Back 42

It is more positive for dimmer stars (larger numbers)

Front 43

Which star is more luminous? A star with an absolute magnitude of 2 or a star with an absolute magnitude of 5?

Back 43

A star with an absolute magnitude of 2.

Front 44

Which star appears brighter? -2 or -3?

Back 44

-3

Front 45

The star that has the lowest negative value will appear the

Back 45

Brightest

Front 46

Absolute magnitude is the brightness of a star if It were

Back 46

10 parsecs away

Front 47

In apparent magnitude, the lower th number....

Back 47

The brighter the star appears to us from Earth.

Front 48

If a White Dwarf accretes enough gas from its companion, it can exceed

Back 48

1.4 solar masses

Front 49

If a White Dwarf doe not reach 1.4 solar masses it will

Back 49

Ignite the has in a runaway thermonuclear explosion called a Type 1a Supernova

Front 50

Afters massive star supernova event, what is left behind?

Back 50

Either a neutron star or a black hole

Front 51

Why would the Sun become a Type 1a Supernova?

Back 51

Because it does not have a companion star.

Front 52

For main sequence stars, bigger stars are

Back 52

Hotter

Front 53

A White Dwarf spectral O will be hotter, more luminous, or smaller than a main sequence star of the same spectral type?

Back 53

Smaller

Front 54

Two stars that have the same spectral type will also have the same luminosity, size, temperature, or absolute magnitude?

Back 54

Temperature

Front 55

A large main sequence star will be smaller, hotter, dimmer door have a larger absolute magnitude than a main sequence star?

Back 55

It would be hotter

Front 56

Large-scale have higher, longer or shorter rates of fusion than smaller stars and have lower, longer, shorter or higher lifetimes?

Back 56

Higher rates of fusion and shorter lifetimes

Front 57

What will be the lifetime of a star that is smaller than our Sun? Shorter than 10 billion years? Exactly 10 billion years? Or longer than 10 billion years?

Back 57

Longer than 10 billion years

Front 58

What scythe lforcevthat causeway clouds collapse, forming stars? Gravity? Radiation pressure? Electron degeneracy pressure? Or neutron degeneracy pressure?

Back 58

Gravity

Front 59

Which of the following lists, in correct order, a possible evolutionary path For a star? A. Main sequence star, red giant, Type 2 supernova, white dwarf? B. Main sequence star, red giant, Type 1a Supernova, white dwarf? C. Main sequence star, red giant,Type 2 supernova, black hole, white dwarf? D. Main sequence star, red giant, Type 2 supernova, neutron star? Or E. Main sequence star, red giant, planetary nebula, neutron star?

Back 59

D. Main sequence star giant, Type 2 supernova, neutron star.

Front 60

What is the eventual fate of a star with a core mass that is 2 times as massive as the Sun? To collapse into a black hole? To become a neutron star? To become a white dwarf? Or to explode as a Type 1a Supernova, leaving nothing behind?

Back 60

To become a neutron star

Front 61

What is the next phase in Tyneside of a star after the planetary nebula stage? A red giant? A planetary nebula? A type 1a supernova? A type 2 supernova? Or a White dwarf?

Back 61

A white dwarf

Front 62

Which star could create a Type 1a Supernova? An O type star without a companion? An O type star with a smaller companion? A G type star without a companion? A G type star with a smaller companion? Or all of the above?

Back 62

A G type star with a smaller companion

Front 63

What prevents a neutron stardom collapsing? Electron degeneracy pressure? Radiation pressure from fusion? Neutron degeneracy pressure? Or Gravity?

Back 63

Neutron degeneracy pressure

Front 64

Suppose that there is a binary system consisting of an M-type main sequence star and an M- type red giant star. In which situation would you receive the least amount of light? When the main sequence star is in front of the red giant? When the red giant is in front of the main sequence star? Or in both scenarios you would receive the same amount of light?

Back 64

In both scenarios above you would receive the same amount of light.

Front 65

Which of the following is true of a binary star system consisting of an M-type main sequence star and a B- type main sequence star? A. You will receivables energy when the B- type star is behind the M- type star than when the M-type star is behind the B- type star. B. The time it takes for the M- type star to pass behind the B- type star is shorter than the time for the B-type star to pass behind the M- type star. C. The force of gravity exerted on the B- type starchy the M- type star is stronger than the force of gravity exerted on the M-type star by the O-type star. D. The orbital period. E. All of the above.

Back 65

A. You Wil receive less energy when the B type star is behind the M type star.

Front 66

In a binary system with two stars of differing temperatures, in which situation do yo you receive more light? When the hotter star is in front of the cooler star. B. When the cooler star is in front of the hotter star. C. You receive the same amount of light in both scenarios.

Back 66

When the hotter star is in front of the cooler star.

Front 67

When the absolute magnitude number is the same as the apparent magnitude number, then that star will be..

Back 67

The one that appears brightest to us.

Front 68

In main sequence stars, hotter stars are more...

Back 68

Luminous and bigger

Front 69

Describe the life sequence of a star with a core mass that is 4 times the mass of the Sun and has a smaller companion n

Back 69

Cloud of gas and dust, main sequence star, red giant, Type 2 supernova, black hole, accretion, X-Ray source

Front 70

Describe the life sequence of a star with a core mass that is 2 times the mass of the Sun.

Back 70

Cloud of gas and dust, main sequence star, red giant, Type 2 supernova, neutron star.

Front 71

less than 1.4 mass of the Sun equals

Back 71

White dwarf

Front 72

1.4 to 3 mass of the Sun equals

Back 72

Neutron star

Front 73

Greater that 3 mass of the Sun equals

Back 73

Black hole

Front 74

Rank the lifetime of a G, O, and K main sequence star from shortest to longest

Back 74

O,G,K

Front 75

When the apparent magnitude is less than the absolute magnitude, the the distance is

Back 75

Less than 10 parsecs, so closer to us.

Front 76

When the apparent magnitude is greater than the absolute magnitude, than the distance is

Back 76

Greater than 10 parsecs, in other words, further than us

Front 77

When the apparent magnitude is the same as the absolute magnitude, than the distance is

Back 77

Exactly at 10 parsecs

Front 78

When You are asked which star is more luminous, you are also asking

Back 78

Which star as the higher absolute magnitude, in other words which star has the greater negative number. The lower the number, the greater the absolute magnitude, aka the higher the luminosity.