Astro 7n ALL COMPREHENSIVE exam 2 study guide

Includes all copper quizzes from units 3 & 4 Art projects 3 and 4 quizzes And basically everything in between

What is the general result of a proton-proton chain?

4 H->He + energy + other products

The corona of the sun is visible when?

solar eclipse

In the convective zone of the Sun:

columns of hot gas rise, cool, and descend

What part of the Sun do we typically see?

photosphere

In nuclear fusion, energy is produced because...

the mass of the reacting chemicals is larger than that of the products

When using different points in the Earth's orbit as a baseline for a parallax experiment it is best to do the observations:

6 months apart

One star is four time farther away than another. The parallax angle of the more distant star is:

four times smaller than that of the nearer star

the parallax angle for the star Hadar is 0.010 arcseconds (0.010"). How far away is Hadar?

100 pc

Put one of your thumbs at arm's length in front of your face. Now focus on something in the background and look through one eye at a time. What do you notice about your thumb?

It appears to move more when it's closer

Star A is 4 times as luminous as Star B. Star A is 2 times as far away as Star B. Which star appears brighter and by how much?

The stars appear the same brightness.

find the hottest star

1

find the star with spectral type F0 on the main sequence

4

find the star with the lowest luminosity

6

Find the main sequence star with the temperature 16,000k

2

find the star with a temperature of 3000k and a luminosity of 50 solar luminosities

7

find the star with the lowest mass

6

find the red giant star with the largest radius

8

find the bluest star

1

find the star with largest radius

8

find the star with the longest lifetime

6

find the sun

5

find the star which would appear brightest if all were at the same distance

8

find the white dwarf

10

find the B5 type star with a radius of 80 solar radii

9

find the main sequence star with 500x the luminosity of the sun

2

find the closest main sequence star, if all of them have the same apparent brightness

6

find the main sequence star with a radius of 2 solar radii

4

find the star whose temperature is closest to 10,000k

3

find the coolest star

8

find the main sequence star that is the farthest away, if all appear the same brightness

1

An "onion skin" shell burning structure, with elements up to iron being produced, develops in:

a star much more massive than the sun

What is at the center of a planetary nebula?

the core of the dying star and something that will eventually become a white dwarf

How do solar-sized and smaller stars die? About how large are their remnants?

They become white dwarfs, about the size of the earth

what does not happen when an object approaches a black hole?

it becomes redder because photons lose energy

B: time runs more slowly as it gets closer to the black hole

C: it quickly gets sucked in even from a large distance

D: it gets stretched out because of tidal forces

E: none of the above

it quickly gets sucked in even from a large distance

how can we measure the mass of a black hole?

measure the speed of the orbit of a star in a binary system with the black hole

What is the main requirement for a habitable zone?

liquid water

a star that is twice the mass of our sun would have a habitable zone that includes

includes mars but not earth

a star that is 75 percent the mass of our sun would have a habitable zone that

includes venus only

what factor is not in the Drake equation?

communication lag due to large distances between stars

what does the drake equation estimate

The number of technological civilizations in the Milky Way

what are the differences between open star clusters and globular star clusters?

open clusters are less concentrated, younger, and have fewer stars

which of the following is FALSE?

a supernova is an explosion of a high mass star at the end of its life
b) a nova can be caused by a white dwarf gaining material from a nearby companion star
c) a type la supernova is caused by addition of hydrogen-rich material on a white dwarf
d) a light echo is caused by light from an exploding star that gradually reaches different layers of gas around the star
e) a nova is more luminous than a supernova

a nova is more luminous than a supernova

what kind of a gas cloud can collapse and form stars

the gas cloud must have a mass that exceeds the Jeans mass so that gravity overcomes the internal pressure in the cloud

what is the mass of the black hole at the center of the milky way

4 million solar masses

how do you measure the mass of the supermassive black hole at the center of the milky way

look at the orbits of nearby stars and apply Kepler's third law

about how long does light take to cross the milky way galaxy

about 100,000 years

what does our galaxy look like?

A. It has a large disk with spiral arms, and is relatively flat and thin
B. It has clouds of gas and dust in the spiral arms
C. Older yellow stars are found mostly in the center bulge
D. Old stars and globular clusters are located in a spherical halo above and below the disk.
E. All of the above

all of the above

why do stars in the halo of the galaxy have almost no heavy elements such as carbon, nitrogen, and oxygen?

halo stars formed before those elements were made

where do stars form in the galaxy today

in the disk

where are open clusters found

in the disk

in the symbol for the hubble type of a galaxy, SBc, the B denotes

the presence of a bar

what happens to the planets in a galaxy when that galaxy collides with another galaxy

nothing, because the spaces between stellar systems in a galaxy is much larger than their size

white properties of spiral galaxies allow us to sub classify them as Sa, Sb, or Sc

size of buldge and extent of spiral arms

compared to spiral galaxies, elliptical galaxies have:

_ gas, __ colors, _ new star formation

less gas, redder colors, and less new star formation

what is the difference between an E0 and an E7 galaxy

the E7 has an oval shape and the E0 is circular

according to models of galaxy formation, which population of stars formed first

the spheroidal population

what type of galaxy can result from collisions between galaxies

elliptical/irregular

what is a starburst galaxy

a galaxy with a very high rate of star formation

In what part of the spectrum are starburst galaxies brightest?

infrared

what parameters do hubble's law relate to each other

galaxy recession velocity and distance

what technique for measuring distance can you use to discover Hubble's law?

cepheid variables in galaxies and white dwarf supernovae in galaxies

how do you measure the speed of a galaxy relative to you

doppler shifts

what is Hubble's Law?

The faster a galaxy is moving, the farther away it is.

where is the center of the universe

There is no center to the Universe. Expansion is happening everywhere.

How have astronomers interpreted the unexpectedly fast rotation of galaxies?

there must be a lot of dark matter whose gravity can be felt but not seen

which of the following is not true about dark matter

dark matter is the dominant source of gravity in the universe.

dark matter and dark energy are two aspects of the same phenomenon.

evidence for dark matter has been building for many decades

all the above

dark matter and dark energy are two aspects of the same phenomenon

why do we think there is a lot of dark matter in clusters of galaxies?

A. individual galaxies are moving so fast that they could not be held together by the gravity of visible matter

B. we’ve detected some of it with dark matter telescopes

C.and gravitational lensing lets us measure mass even when we can't see it

D. squidward

A and C

how do we know that the universe is speeding up

we look at objects from different times in the past to see how expansion changes with time

how could the universe be accelerating, despite the gravitational pull of all the matter in it

there could be a new force or property of space that affects the universe on its largest scales

what fundamental particles make up a Hydrogen-1 atom

one proton, one electron

which force is responsible for holding the nucleus together via gluons

strong

what three fundamental particles are you made of

up quarks, down quarks, and electrons

how many types of fundamental particles exist

300

how many up quarks are there in helium-3

5

which has the events in the right order from early to late

star formation

quark soup

nucleosynthesis
protons form,

recombination

quark soup, protons form, nucleosynthesis, recombination, star formation

what happens because of recombination

the cosmic microwave background is produced

what forms in nucleosynthesis

most of the Helium-4 in the Universe

what is a quasar

a very luminous source due to a black hole at the center of a galaxy that is quickly growing

how did conditions differ from the present era when the universe was young

the universe was hotter, more dense, and smoother

What occurs when electromagnetic activity in outer layers cause cooling in regions?

sunspots

What percent of solar system mass is the sun?

99.9%

The region of the sun where most visible light is emitted. 6,000 K

photosphere

outside the photosphere with cooler and thinner gas

chromosphere

grainy “bubbly” texture of the sun

granules

a large region below the phtosphere

convective zone

powerful burst of energy on the sun influenced by local magnetic activity

solar flare or prominence

where in the sun does energy travel outward through absorption and re-emission of photons

radioactive zone

place in the sun with high density and temperature; where nuclear reactions occur
and gamma rays are produced

core

first step of pp chain

a proton combines w another to make hydrogen 2, 1 proton is now a neutron

second step of pp chain

_h + _h = _h?

hydrogen two combines with hydrogen to make hydrogen 3

final step of pp chain

_he + _he = _he?

3 he combines with 3 he to make 4 he

absolute power output to a source

luminosity

apparent output observed by distance

brightness

formula for brightness=

luminosity / 4pi(distance)²

formula for distance

1/parallax angle

formula for distance in parsecs

1 / parsec

what does it mean to be a main sequence star?

where stars can covert hydrogen to helium in their cores

what is the sequence of events for a sun-like star?

arrange these in the right order:

white dwarf

protostar

planetary nebula

red giant

sun-like star

protostar, sun-like star, red giant, planetary nebula, white dwarf

What do low mass stars become?

Planetary nebulas and white dwarves

what do medium mass stars become?

super novas and neuron stars