ES 110 - Exam #3

What have we learned from the work of Harlow Shapley, we are in the disk of the Galaxy, about __________________ of the way from the center

3/5

An approximately spherical cluster of over 100,000 stars that formed at the same time long ago in our galaxy is

A globular cluster

What factors are important when trying to classify a spiral galaxy ?

All of the above

Why is the use of Hubble's Law to measure distances to galaxies so important to astronomers?

Because most galaxies are so far away

(T or F) Proton-proton reaction: Four helium nuclei are converted into a hydrogen nuclei

False

(T or F) The Andromeda Galaxy has spectral lines that show a blue shift. From this we may conclude that: this galaxy is moving far away from us

False

(T or F) The nuclear bulge or core contains the lowest density of stars in the galaxy.

False

(T or F) The process of fusion that keeps our Sun shining begins with two neutrons.

False

(T or F)Sunspots are darker then the regions of the Sun around them because they are warmer than the material around them.

False

How did Harlow Shapley determine where the center of the galaxy lies?

He plotted the distribution of globular clusters

The granulation pattern that astronomers have observed on the surface of the Sun tell us that:

Hot material must be rising from the Sun's hotter interior

Atoms typically consist of electrons, protons, and neutrons. The most common isotope of one element, however, only has two of these three types of particles. This element is:

Hydrogen

The most common element in the Sun is

Hydrogen

The idea that atoms radiate energy only when their electrons move from higher to lower energy levels was first advanced by:

Niels Bohr

Where in the Sun does fusion of hydrogen occur?

Only in the core

Which of the following is the largest object?

The local group

(T or F) Astronomers consider any chemical element heavier than hydrogen a metal.

True

(T or F) Sagittarius A* is believed to be the location of a supermassive black hole.

True

(T or F) The center of our galaxy shows signs of past eruptions.

True

(T or F) The halo is believed to be composed mainly of dark matter that exceeds even beyond its ends.

True

(T or F) The material inside the Sun is in the form of a plasma (plasma: a hot ionized gas)

True

(T or F) The sun makes most of its energy by the proton-proton cycle.

True

(T or F) When we pass a beam of white sunlight through a prism, we see a rainbow-colored band of light that we call a continuous spectrum

True

(T or F)Our star's spectrum is crossed by dark lines produced by atoms in the solar atmosphere that absorbs light at certain wavelengths.

True

(T or F)Quasars are very powerful and compact sources of energy at the centers of distant galaxies.

True

(T or F)When the astronomers take an absorption line spectrum of the Sun, these absorption lines tell us what elements are present in the outer layers.

True

The light which allows you to see this very interesting exam is made up of waves. In these waves, the distance between crests is called the:

Wavelength

Herschel was right about the shape of our system but __________ about where the Sun lies within the disk.

Wrong

At the end of the p-p chain of nuclear fusion in the Sun, hydrogen nuclei have been converted into:

a helium nucleus

This chapter discusses that light sometimes acts like a photon. What is a photon?

a self-contained "packet" of electro-magnetic energy

Physicists Kelvin and Helmholtz in the last century proposed that the source of the Sun's energy could be:

a slow contraction

Two stars are giving off electromagnetic radiation. The hotter star will:

all of the above

Which of the following statements about the violent events on the Sun called flares is FALSE?

astronomers think that flares are connected with sudden changes in the magnetic field of the Sun.

How fast do electromagnetic waves travel?

at the speed of light

Convection is important in stars because it

b and c (mixes the gases of the star. transports energy outward in the star.)

Poor clusters

contain fewer than 1000 galaxies and tend to be irregularly shaped.

Which part of the Sun's atmosphere is the hottest?

corona

The ten million tons of particles that escape the Sun each year in the form of the solar wind get out mainly through regions called:

coronal holes

The quasars demonstrate that the universe evolved with time, the number of quasars reached a maximum some time ago, and now the numbers have been:

declining

In the proton-proton chain

energy is produced in the form of gamma rays and the velocity of the created nuclei.

The time it takes the Sun to revolve once around the center of the Milky Way Galaxy is called ________________ year

galactic

Spirals Galaxies are rich in:

gas and dust

The first stars to form in our galaxy

had highly elongated elliptical orbits.

Irregular galaxies are

highly irregular in shape and tend to be rich in gas and dust

The condition of _________________ ___________________ means that the force due to gravity pushing down on a layer is exactly equal to the pressure pushing outward on that layer

hydrostatic equilibrium

Two versions of an element with different numbers of neutrons are called:

isotopes

When a large nucleus breaks apart (or is broken apart) into two smaller pieces, this is called

nuclear fission

You are out on the beach, enjoying the warm sunshine with friends. As you glance up at the Sun (only briefly we hope), the part of the Sun that you can see directly is called its:

photosphere

Flame like protrusion seen near the limb of the sun and extending into the solar corona; the side view of a filament is called ___________________

prominence

The Sun's chromosphere contains many jet-like projections that stick up into transition region. These spikes of gas are called:

spicules

Wien's Law relates the wavelength at which a star gives off the greatest amount of energy to the star's

temperature

The Sun's photosphere is

the part of the Sun from which the light comes that we see when we look at the Sun with our eyes