Reference no: EM131702110

Assignment: Earth & Astronomical Science

Part ONE

Chapter 24 - Stars

1) What is the most basic method of determining stellar distances? EXPLAIN the method!

2) Explain the difference between a star's apparent and absolute magnitudes. Which one is an intrinsic property of a star?

3) What information about a star can be determined from its color?

4) Enumerate in as much detail as you can, the steps thought to be involved in the evolution of Sun-like stars. (in your own words! An outline with details is fine)

5) How do the "lives" of the most massive stars end? What are the two possible products of this event?

Chapter 24 - Galaxies & Cosmology

6) Describe the general structure of the Milky Way Galaxy

7) Compare and Contrast the basics of Spiral, Elliptical, and Irregular Galaxies

8) In your own words, explain how astronomers determined that the universe is expanding.

9) What is Dark Matter? Why is it significant?

10) Astronomy & Earth Science - Bring the Sciences Together- Describe how Earth Science and Astronomy are related or interconnected and how they are used together in the "real world." Include very specific examples from topics covered in the course as well as think of some "real world" applications including technology and instrumentation. Pick at least two specific concepts/topics/examples and go into detail using terms and information learned in the course. How are these sciences related? How do they feed off each other? How has the use of technology or instrumentation in one science, inspired technology/instrumentation in the other? How are these sciences related to your daily life? Be specific in your reasoning and show me what you have learned!

(Example - Relative dating of Earth surface features using superposition (Earth Science) is applied on the Moon and other planets in our Solar System to help determine relative ages of surfaces on those bodies (Astronomy). For example looking at when volcanoes were formed on Venus. Then you would give some explanations of these concepts that you learned from the class...)

Part TWO

Question 1
A white dwarf star is at what stage of its evolution?
post-supernova stage, after the explosion of a star
main-sequence phase, "middle-aged"
very late phase of evolution
protostar phase, just after formation

Question 2
When a supernova explosion results from core collapse in a massive star it appears to leave behind
nothing, the explosion changes all the matter completely into energy, which then radiates into space at the speed of light.
a rapidly expanding shell of gas and a compact white dwarf star at its center.
a rapidly expanding shell of gas and a central neutron star or black hole.
a rapidly rotating shell of gas, dust, and radiation, but no central object.

Question 3
Based on the observed red shifts in the spectral lines of distant galaxies, astronomers conclude that __________.
Earth is in the center of the universe
the universe is contracting
the universe is expanding
the universe is in a steady state

Question 4
What happens to the surface of a low-mass star after the helium core and helium shell nuclear fusion "burning" stages are completed?
It contracts back onto the core and becomes hot enough to undergo further hydrogen fusion, leading to a very hot and active white dwarf star.
It is spun off into space to form a spiral galaxy.
It stabilizes at the size of a red giant star, the radiation pressure from below balancing gravity from the core, to cool slowly for the rest of its life.
It is propelled slowly away from the core to form a planetary nebula.

Question 5
A star remnant in which light cannot escape because of the immense gravitational pull is called a(n): _____________.

Question 6
The evolution of a star is controlled mostly by its
initial mass.
location in the galaxy.
chemical composition.
surface temperature.

Question 7
The Milky Way is classified as a spiral galaxy.
True
False

Question 8
A planetary nebula is
a contracting spherical cloud of gas surrounding a newly formed star, in which planets are forming.
a disk-shaped nebula of dust and gas from which planets will eventually form, easily photographed around relatively young stars.
the expanding nebula formed by the supernova explosion of a massive star.
an expanding gas shell surrounding a hot, white dwarf star.

Question 9
After a star becomes a red giant, hydrogen fusion
occurs only during the helium flash and then stops fusing all together
occurs in a shell around the core, while Helium fuses in the core
occurs in the core with Helium fusion
no longer occurs, only Helium is being consumed to fuel the star

Question 10
What is this an image of?

eagle
A. Dark Matter
B. Nebula
C. Star Birth Region
D. Only Helium Gas
E. Answer B & C
F. Answer B, C & D

Question 11
As you move upward and to the left on the HR diagram the stars become
hotter and redder.
cooler and redder.
cooler and more white.
hotter and more white.

Question 12
The least massive main-sequence stars are blue in color.
True
False

Question 13
For this question please refer to Figure 24.8 (pg. 694) - 13th Ed / Figure 24.7 (pg. 682) - 12th Ed
(or attached image, click on image name to open image)
Using the HR Diagram, what would be the color of a main-sequence star whose surface temperature is 3,000K?
HR Diagram
Red
Blue
Green
Yellow

Question 14
Our Sun will become a Red Giant star
True
False

Question 15
Can we actually see the Milky Way Galaxy from Earth?
No, we cannot see the Milky Way Galaxy from Earth. The clouds and light pollution on Earth will obscure our view of the galaxy no matter where you are on Earth.
No, we cannot see the Milky Way Galaxy from Earth. We are the galaxy so it is impossible for us to see it.
Yes, we can see the Milky Way Galaxy from Earth. Earth is located within the spiral arms of the galaxy, so we can see the gas and dust from within. We can also see above and below the galaxy, that is the rest of the "dark" sky we see at night, riddled with stars beyond our Galaxy.
Yes, we can see the Milky Way Galaxy from Earth. Earth is located within the spiral arms of the galaxy, so we can see the gas and dust from within, which covers our entire night sky. Every star we see in the night sky is part of the Milky Way Galaxy.

Question 16
How can astronomers find a Black Hole if it can not reflect or emit any energy?
Observe the effects of the Black Hole's gravitational field
Talk the Black Holes into showing their "True Colors" for astronomers to see
We can't look for them, we have to wait until they get close enough to Earth to see.
Black Holes can be seen in the Infrared wavelengths, so use infrared detectors

Question 17
Why do we experience seasonal changes and Why is it warmer in the Summer and Colder in the Winter on Earth?
We experience seasonal changes because the Earth's rotational axis is tilted by 23.5 degree from perpendicular! The Earth orbits the Sun once a year in a very extreme elliptical orbit, meaning that as the Earth orbits the Sun we get closer to the Sun and further from the Sun. When the Earth is closer to the Sun, it is summer and much warmer. When the Earth is furthest from the Sun in its orbit, it is much colder, so winter season.
We experience seasonal changes because the Earth's rotational axis is tilted by 23.5 degree from perpendicular! The tilt causes one half (hemisphere) of Earth to point towards the Sun in the summer and away from the Sun in the winter. It feels warmer in the summer because the tilt towards the sun allows for more direct solar rays to hit the ground, warming up the Earth! Also, the daylight hours are longer when tilted towards the Sun, so more time to warm the Earth! The opposite is true during the winter.
We experience seasonal changes because the Earth's rotational axis is tilted by 23.5 degree from perpendicular! The tilt causes one half (hemisphere) of Earth to be much closer to the Sun in the summer and much further from the Sun in the winter. Because the Earth gets closer to the Sun, it feels warmer in summer. The opposite is true during the winter.
We experience seasonal changes because the Earth's rotational axis is tilted by 45.3 degree from perpendicular! The tilt causes one half (hemisphere) of Earth to point towards the Sun in the summer and away from the Sun in the winter. It feels warmer in the summer because the tilt towards the Sun allows for more indirect solar rays to hit the ground, warming up the Earth! Also, because the Earth gets closer to the Sun, it feels warmer in summer. The opposite is true during the winter, it is colder due to direct solar radiation and being much further from the Sun.

Question 18
Stars spend most of their life span as main-sequence stars
True
False

Question 19
Apparent magnitude is a measure of the
temperature of a star.
size (diameter) of a star.
intrinsic brightness (actual light output) of a star.
brightness of a star, as seen from Earth.

Question 20
The Sun is really just a 'normal' main sequence star.
True
False

Question 21
The Hertzsprung-Russell diagram is a statistical plot of which of the following two stellar parameters?
luminosity and mass
radius and mass
mass and surface temperature
luminosity and surface temperature

Question 22
Which of the objects listed below has the largest size?
globular clusters
galaxies
stars
nebula

Question 23
What is a pulsar?
a pulsating white dwarf star, fluctuating rapidly in brightness
a rapidly rotating neutron star, producing beams of radio energy and in some cases, light and X-rays
a Cepheid variable star with a period of a few days
a rotating black hole, producing two jets of gas in opposite directions and pulses of gravitational energy.