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Alston Potts
Ben Caulfield
Jesse Bond
Table of Contents
Big Bang
p. 3
p. 4
p. 5
p. 6
p. 7
p. 8
The Beginning
Events of the Big Bang
Universal Expansion
History of Human Understand of the Big Bang
p. 9 Introduction
p. 10 Formation of Galaxies
Galactic Phenomenon:
Black Holes
p. 11
Galactic Interaction
p. 12-13
p. 14
Types of Galaxies:
p. 15
p. 16
p. 17
p. 18
p. 19
Star Systems
p. 28
Introduction: What is a star?
Formation of Stars
Types of Stars
Types of Star-related Systems:
Planetary Systems
Binary and Multiple Star Systems
About the Authors
Image Credits
The Beginning
The most widely accepted scientific theory on the beginning of
the universe is known as the Big
Bang Theory. Scientists believe
that all matter, life, and energy
began as a singularity. This
zone is believed to exist at the
center of a black hole as exAn artistic interpretation of the Big
tremely tiny, infinitely dense, and Bang
molten hot particle (one for every
black hole). Many people believe that the big bang was the
result of an exploding singularity, but many scientists believe
that it occurred because this particle (singularity) rapidly inflated to the size of our current universe, cooling down as it
expanded. The universe continues to expand and cool down,
and, as far as scientists can predict, will continue to do so
Did you know?
Scientists from New Jersey, Arno Penzias and Robert Wilson, accidentally discovered the existence of cosmic microwave radiation while
trying to intercept radio waves. Because of this discovery they were
awarded the Nobel Prize in Physics and brought us one step closer to
discovering the beginning of the universe.
Events of the Big Bang
The Big Bang
Universe begins to expand
Gravity becomes evident
Formation of the basic elements
Radiation forms from the initial energy of the Big
Energy in matter and radiation become equal
Stars and galaxies form
Satellite image of our sun.
Did you know?
Our sun formed approximately five billion years ago, which is very
young in the life of the universe. It is believed to be about fourteen billion years old.
Everything in the universe can be divided
into one of two categories: matter and energy.
Matter can be identified
by its characteristic elements known as atoms.
An atom has protons,
neutrons, and electrons A representation of the three states of matter.
within its structure.
These are known as subatomic particles. All matter can exist in three stages: solids, liquids, and gases. Both solids and
liquids have a fixed volume, while gases take on the volume
of the containing space. Temperature is the factor that ultimately decides what form matter will take; matter is in solid
form at cold temperatures, in liquid form at warmer temperatures, and in gas form at the warmest temperatures. The temperatures in which these forms occur are different with every
different kind of matter.
Did you know?
Many cosmologists theorize the existence of a strange form of
matter known as dark matter. This explains the space between
celestial bodies. The scientists say that this kind of matter does
not actually have any atoms, so it is incorrectly labeled.
Energy, on the other
hand, is not made
up of atomic nuclei.
Most energy can be
found on the light
spectrum, which
ranges from radio to
gamma rays. Energy can be organ- The light spectrum, the projected area is all that we are
ized into categories able to see
based on the size of
the wavelength, varying from energies of long wavelengths
to energies of shorter wavelengths (lower energy to higher
energy). Humans can only see a small portion of all waves
found in the universe; these waves are found in the visible
portion of the spectrum. Cosmic rays do not have a place on
the spectrum because they are particles with high charges
that travel through space at the speed of light.
Did you know?
With the aid of current technology such as infrared cameras
and ultraviolet light bulbs we are able to see some of the
waves on the spectrum that we are naturally unable to sense.
Universal expansion
The universe is constantly
expanding. This actually
occurs in the space between celestial bodies
such as stars, planets, and
asteroids. If you imagine a
loaf of raisin bread you
may understand this conThis image shows the path of expanding
cept better. Before you
bake the bread, it is a
dense wet dough with raisins mixed into it. When
you put the dough in the oven and begin to bake it,
the bread expands. But do you think the raisins expand along with the dough? Of course not. The sizes
of the raisins are not affected by expanding bread;
however, the distance between them increases. The
masses, or raisins, do not change in size, but the
space, the dough between them, increases. Unlike the
bread, would eventually reaches a point where it
stops expanding and burns, the universe never stops
Human Understanding
Of The Big Bang
Edwin Hubble (1889-1953) was
an American astronomer who
discovered that there are more
galaxies than just our galaxy.
From this discovery he developed Hubble’s Law, which
simply states that the universe
is continually expanding. This
law lends proof to one of the
most widely known scientific
theories, the Big Bang Theory.
Despite its familiarity, there remain a few misunderstandings
about the theory. The most common misconception is the belief that the Big Bang actually started with a big noise. There
was, however, no explosion because this event is believed to
be more like the inflation of a balloon rather than a bang.
Another incorrect idea is the belief that before the Big Bang
there was just one singularity floating in space. There was,
however, no space during this time - just the one speck and
nothing else.
Hoag’s object (top) , the sombrero galaxy (middle) , and two
colliding spiral galaxies
Galaxies are gigantic
collections of stars, gas, dust,
and remnants of dead stars.
They are formed when a large
black hole appears and uses a
gigantic amount of gravity to
pull galactic debris towards the
center. Galaxies are grouped
into different types, including
spiral, elliptical, lenticular,
dwarf and irregular galaxies.
They range in shape, size,
amount of stars, and visible
appearance. Although some
exist solely by themselves,
many galaxies are organized
into galactic clusters, which are
also held together by gravity.
These clusters can then be
organized into super-clusters,
which are the largest objects in
the universe to be held together
by gravity.
Galaxy Formation
Following the trend
of starting small and
getting bigger, galaxies also began the
same way. Galaxy
formation is still being actively researched, but it is believed that the phenomenon began approximately 300,000 A newly formed galaxy is shown in the bottom left
portion of this image
years after the Big
Bang. It began with
recombination, which is the formation of neutral hydrogen and helium atoms by the combination of stray protons and electrons. As the galaxy continues to develop, it
starts to form galaxy clusters with other galaxies. This
period in the existence of a galaxy is known as its evolution. At this time the key structures begin to appear, such
as the central supermassive black hole and stars.
Black Holes
You’ve probably
heard something about black
holes in science fiction, in the
news, or in school. A black
hole is usually described as a
mysterious black object that
will suck anything into it.
These lurking monsters are
often said to lurk in the deepest reaches of the universe.
In reality, this description of
a black hole is only partly This artist’s rendering of a black hole shows that
true. In the universe, black light even light can’t escape this massive amount of
holes area naturally occurring gravity.
phenomena. First, we must
discover how black holes are formed. On the page prior to this, you
learned about supernovas and the death of stars. In some rare occasions, an exploded star will collapse in onto itself from an overwhelming amount of gravity. Note that this is the same gravity that makes
apples fall from trees on earth, but a much stronger amount. The collapsed star will become what is known as a black hole. Now you may
be wondering, ―What makes this collapsed star a black hole?‖ A black
hole has such an exceptionally gigantic amount of gravity that it is able
to consume anything that wanders too close to its surface. It even will
cause light to become trapped inside of its menacing body. Without
light to bounce back, the entity is perceived as a black object.
Did you know?
To our knowledge, light travels faster than anything else in the entire universe. It clocks a whopping speed of 671,000,000 miles per hour! To put
this into perspective, the fastest man made jet travels at only 2,293 mph.
Galactic Interaction
The mice galaxies are two interacting galaxies that are in the process of colliding
with each other,
Galactic interaction occurs when one galaxy is distorted by
another. It appears by a variety of processes, including satellite interaction, galactic collision, and galactic cannibalism. Satellite
interaction, which is found in smaller galaxies orbiting larger counterparts, can affect both the satellite and the mass it orbits. The larger object, or primary, is capable of completely disfiguring the
smaller galaxy. The satellite, on the other hand, can gravitationally
pull the arms of the primary outward. Galactic collision can occur
between two galaxies of any size or type and can have a far greater
impact than satellite interaction. You might imagine these collisions
as colossal crashes of galactic proportions; however, because matter
is distributed loosely in galaxies, these collisions are not the expected impacts. In reality¸ colliding galaxies only affect each other
through gravity, and they may even pass through each other unaltered. On the other hand, if the galaxies lose their momentum, they
might merge into a single, larger galaxy.
Galactic Interaction
This image shows galactic cannibalism as a larger galaxy collides with a
smaller one.
The final type of galactic interaction, called galactic cannibalism, occurs between two galaxies of greatly different
sizes. The larger galaxy pulls the other mass towards it, and
the matter from both objects is combined. In this process, the
larger galaxy remains generally unaffected, but the smaller
galaxy is almost completely destroyed.
A supernova is an enormous explosion that is
formed when a star (see
p. 21) becomes too massive and too old to support itself and collapses.
can come in many
forms, they are normally
classified into two main
types. The first type is
formed when a small This picture of the Keplar supernova
star gives some of its shows the brightness and energy that
is common to most supernovae.
equally tiny star. The tiny star eventually gains too much mass
to maintain itself and explodes into a supernova. The second
type of supernova is formed when an already massive star
becomes too old and runs out of energy. With no other forces
involved, gravity is left to pull inwards on the star, which
collapses into a supernova. The explosion itself is a spectacular
burst of light so bright that it can occasionally outshine an
entire galaxy.
Did you know:? Supernovae give off 1038 tons of
energy. That’s more than an
14 octillion nuclear bombs!
Spiral Galaxies
Of the various types of
galaxies, the spiral galaxy is by
far the most common. In fact,
About 77% of all known galaxies are spiral. There are a few
main features that are found in
all spiral galaxies, including a
disc-like shape and a galactic
bulge. The discs are usually This image of a spiral galaxy clearly
formed by two spiraling arms shows the two spinning arms, the
orbiting halo of stars, and the bulge
that come from the center of of stars in the center.
each galaxy. The galactic bulge,
which makes up the center, is a dense group of older stars. In
addition, all spiral galaxies have a center made of a large black
hole: a large opening in space with such strong gravity that
even light cannot escape it. Finally, all spiral galaxies have a so
-called halo of loosely packed stars that are found far-off from
the center of the galaxy. Although all spiral galaxies show these
characteristics, they greatly vary in overall size, density, and
Did you know? The Milky Way, which is the
galaxy that we live in, is a spiral galaxy.
Elliptical Galaxies
Bright, white galaxies are
classified as elliptical.
Because of their brightness, we usually can’t see
any features in these galaxies. Some elliptical galaxies have only a hundred
million stars, while others
contain as many as one
trillion stars, most of
This picture of the M87 galaxy clearly
which are older and shows the bright, sphere-like shape that is
smaller than normal. In common to elliptical galaxies.
addition, because there
isn’t much dust or gas in elliptical galaxies, they form stars very
slowly. Unlike most other galaxies, elliptical galaxies are almost
always found in galaxy clusters. Astronomers believe that elliptical galaxies form when two other galaxies pull towards each
other and collide. Although these impacts were very common at
the beginning of the universe, they are somewhat uncommon
now. In fact, only 15% of all galaxies in the visible universe are
Did you know?
Some elliptical galaxies are 100 million light-years wide!
Lenticular Galaxies
There are some galaxies
that are neither elliptical
nor spiral; they are a mix
of both groups. These
masses, called lenticular
galaxies, make up one of
the most common types of
shapes, sizes, and stars that
are similar to spiral or
elliptical galaxies. Much
like the spiral galaxy, lenticular masses have spiral
arms; however, lenticular
curves are not quite as distinct. In addition, lenticular
galaxies have a disk-like This lenticular galaxy has both the
brightness of an elliptical galaxy and
shape, which is also simithe disk-like shape of a spiral galaxy.
lar to that of spiral galaxies. Much like elliptical galaxies, on the other hand, lenticular galaxies have a very bright galactic bulge. In fact, this bulge is so similar to that of an elliptical galaxy that, when viewed from the front,
the two galaxies are almost indistinguishable from each other.
Furthermore, both elliptical and lenticular galaxies have low rates of
star formation and contain mostly old stars. Lenticular galaxies
combine both spiral and elliptical aspects to form a unique type of
Dwarf Galaxies
Dwarf galaxies are
particularly small
galaxies that contain
very few stars. Galaxies
of any type, such as
spiral or elliptical, can
also be considered
most dwarf galaxies
This is an image of a dwarf spiral galaxy.
have relatively small
amounts of stars (a few billion), some dwarves, which are
called ultra-compact dwarves (UCD), have as many stars as
actual galaxies. One of the most interesting characteristics of
dwarf galaxies is the way they move. Unlike most galaxies,
dwarves are neither grouped in clusters nor alone in space;
instead, these masses are in orbit. In the same way that
planets revolve around the sun, dwarf galaxies move about
larger galaxies. Such orbiting galaxies are also called
satellite galaxies.
Did You Know? There are at least 14 dwarf
galaxies orbiting the Milky Way.
Irregular Galaxies
Not all galaxies have
tidy, circular shapes.
Galaxies with distorted structures are
called irregular galaxies and are both
unique and chaotic.
usually contain large
amounts of gas and
dust which leads to a
high rate of star
These irregular galaxies, known as the
formation. Astronoantennae galaxies, are in the process of
mers believe that merging together.
these irregular masses
form when normal galaxies are distorted through galactic
interaction (see pp. 13-14). Irregular galaxies are categorized
into two main groups, the first of which is called the IRR-1
group. Galaxies within this category display a structure that
is too indistinct to be considered a normal galaxy. IRR-2,
which is the second type of these irregular, heavenly masses,
contains galaxies that have no organization at all. Each type
is fairly common, and the combination of both groups
makes up about 25 % of all galaxies in the visible universe.
What is a Star?
As you probably know, the sun
is a star. If you look up to the
night sky you will be able to
see rays of light emanating
from countless other stars located in the galaxy. That’s all
well and good, but what is a
star? A star is a massive cloud
of gas held together by gravity.
It causes the star to implode in
upon itself by applying enor- A picture of our Sun
mous amounts of force on the
gas. However, as the gas is squeezed together, the outward
pressure of the hot gasses counteracts the effect of gravity.
The result is a relatively stable ball of highly energetic gasses. In the center of a star, high-energy chemical reactions
occur that expel energy from the stellar body. One of the
most recognizable forms of energy expelled in this manner is
light, which give stars the appearance of being ball of light.
Did You Know?
The ancient people Greece and Rome would often look up at
the night sky and connect bright stars with lines; the ancients
could picture exotic animals, legendary heroes, and mythical
creatures from the shapes that were formed, which are now
called constellations.
Formation of Stars
Galactic dust and gas clouds
are the locations for the birth
of stars. The natural pull of
gravity between all matter
causes clumps of dust and
gas to form over vast quantities of time. Eventually, the
clumps will coalesce into
even larger clumps. Gravity
will then cause the dust and
gas cloud to collapse into a
and Gas Cloud—Birthplace of
much denser body. During Dust
this process, the center of the
cloud will become increasingly hot. This is what is known
as a protostar, or the beginnings of the core of what will become an actual star. If there is rotation in the cloud, there is
a chance that the final collapse will cause the gas cloud to
form multiple blobs of matter. In some cases, each of these
blobs might form individual protostars.
Did you know?
The process described above is how scientists believe every
star in the universe was formed. This process is even observable in the current day via powerful telescopes. Dust
and gas clouds have been observed in each of the stages of
stellar formation.
Types of Stars
The numerous categories of stars range
in both size and
color. The majority
of the stars are main
sequence stars. Our
sun is categorized as
a main sequence star.
The brighter the star,
the hotter it is. The Diagram comparing color, size, and brightness
life expectancy is
over 5 billion years. Towards the end of a star’s life,
it will begin to expand becoming what is known as a
giant or supergiant. The final stages of its life are exploding in a supernova followed by becoming a
black hole, white dwarf, or neutron star.
Did you know?
A white dwarf is roughly the size of the Earth. It is a small,
hot, and bright. The final stage is a black dwarf, which is
small, cold, and dark.
NeutroN Stars
A neutron star is formed after the remnants of a supernova
collapses from the pull of gravity. Much like white dwarfs,
neutron stars are very hot and small. The length from end to
end would be around 15 miles long. This is approximately
60,000 times smaller than the sun! Their density is over
200,000,000,000,000 times more than the density of the sun.
The gravity on the surface of an average neutron star is
stronger than on Earth by a factor of 100,000,000,000. The
star will have a solid outer crust that is less than 1 mile thick.
Inside the crust is a liquid interior of molten matter.
A representation of a neutron star.
Star Systems
Stars form a multitude of different systems in the universe.
A few of the more prominent types that will be discussed on
the following pages will be: planetary systems, binary star
systems, and multiple star systems. Below are various pictures and artist renditions of each type.
Top: Planetary Systems, Middle: Binary Star
Systems, Bottom: Multiple Star Systems
Planetary Systems
A planetary system is a star that has orbiting objects within
its gravitational pull. As the dust and gas coalesce into
clumps of matter some of the outer clumps do not become
part of the star. A planet is a remnant left over from the formation of the star that it orbits. During birth of the planetary
system, the largest collections of matter will continue to
combine and grow. A planet has enough gravity to form a
rounded, sphere-like surface. In our solar system, there are 8
planets that orbit around our sun (Pluto isn’t considered a
planet anymore). A smaller type of object that is present in
planetary systems is known by either the name asteroid or
planetoid. They are often depicted as jagged lumps of rock
and ice that do not have any particular shape. Scientists believe that planetoids are the building blocks of planets. In
some planetary systems, rings of asteroids will form asteroid
belts that orbit the star in the center of the system.
Formation of a Planetary System
Binary and Multiple
Star Systems
A basic star system
usually contains one star
at the center of the
However, a
binary star system has
two stars present in the
system. The larger of the
two stars is deemed the
primary star, while the
smaller is called the
Both stars’ Binary star system with a red giant and a blue
gravity will pull on the giant.
other. This results in the
two stars orbiting around each other. A multiple star system is
similar to a binary system, but contains more than two stars. The
additional stars will add their gravitational influence to the
system. The resulting orbit of each star will be more complex
than those of a binary system.
The Search for Extra Terrestrial Intelligence (SETI) Institute is a nonprofit organization that researches and educates astrobiology, the study
of life in the universe. The name, SETI, is an acronym for the Search
for Extra-Terrestrial Intelligence. Currently, SETI scans the night sky
with special telescopes for signs of life in deep space. The telescopes
look for the presence of rhythmic or repetitive signals, as they do not
occur naturally in the universe. If you find SETI interesting, they are
always willing to have more help in their ongoing quest. Luckily,
[email protected] is a freely available computer program that allows personal computers to analyze SETI’s overwhelming amount of unprocessed data. Since June 2009, over 300,000 computers have been involved in the project!
Atom-the smallest part of an element having the chemical properties of the element
Big Bang Theory- the idea that the universe used to be small,
dense, and hot.
Coalesce - to combine or become one
Energy-the ability to do work
Galactic cannibalism– when a primary galaxy swallows its
satellite galaxy.
Galactic collision– when two galaxies use gravity to affect each
Hubble’s Law-the statement that galaxies move away from
each other
Implode - Opposite of explode; to collapse into oneself
Light spectrum-the range of all possible frequencies of
Matter-a substance that has mass and occupies space
Orbit/Orbiting - Moving in a curved path around an object
Primary– the larger galaxy that a satellite galaxy orbits.
Recombination- the formation of neutral hydrogen and helium
Satellite interaction– The interaction between a smaller,
orbiting galaxy and a larger one.
Satellite galaxy– a smaller, orbiting galaxy.
Singularity-the center of a black hole
Subatomic particle-particles that make up atoms (protons, neutrons, electrons) by the combination of stray protons and electrons.
About the authors
Alston Potts, who wrote the Big Bang, matter,
and energy portion of this book, is a Junior at
the Massachusetts Academy of Math and Science at WPI. Before coming to the Academy
he attended Fitchburg High School. He enjoys
playing baseball and guitar. In the future, he
wishes to learn to box. He is looking to attend
West Point and become a civil engineer.
Ben Caulfield, who wrote the galaxy section of
this book, is a Junior at the Massachusetts
Academy of Math and Science. In his spare
time, he enjoys listening to music, playing his
guitar, and reading. His favorite artists include
Phish, Frank Zappa, Bob Dylan, and Blink-182
In the future, he plans to attend the Worcester
Polytechnic Institute.
Jesse Bond, who wrote the section about stars, is attending the Massachusetts Academy of Math and Science as
a currently a junior. He is interested in robotics and has
competed in numerous leagues and events. One of his
most prominent involvements is with Team 190, a
FIRST robotics team where he is the acting president
and school representative. His father has introduced
Jesse to amateur astronomy over the years and has
ready access to a telescope that he may use whenever
he chooses. Jesse Bond has also attended Stellafane, an
annual international astronomy located in Springfield,
Image credits
p.4 -The Beginning:
p.5 -Events of the Big Bang:
p.6- Matter:
p.7- Energy:
p.8- Universal Expansion:
p.9- Human understanding:
p.10- Hoag’s Object-
p.10- Sombero Galaxy-
p.10- Colliding Spirals-
p.11- Galaxy Formation:
p.12- Black Hole-
p.13- Galactic Interaction-
p.14- Galactic Interaction (continued)-
Image credits
p.15- Supernovae-
p.16- Spiral galaxies-
p.17- Elliptical Galaxy-
p.18- Lenticular galaxy-
p.19- Dwarf Galaxy-
p.20- Irregular Galaxies-
p.21- The Sun-
p.23- Hertzsprung-Russell Diagram—
p.24- Neutron Star—
p.25- Solar System—
p.25- Planetary Systems—
p.25- Blue Binary System -
p.25- Binary System—