Stars Constellations and the universe The Universe is

Stars, Constellations and the universe

The Universe is made up of everything that exists in space, such as planets, stars and even us! l The universe was created over 13 billion years ago by a large explosion called l The Big Bang l It is hard to imagine how enormous the universe is. The universe is made up of many different galaxies l

What is a star? l l l A STAR is a large sphere of glowing dust and gases such as helium and hydrogen. Stars change over time. The stars we see from Earth belong to a galaxy known as the Milky Way l Which is the closest star to Earth? THE SUN! l The sun is a medium sized star l MUCH, MUCH larger than Earth l

How are stars created? l Stars are formed when spinning balls of gas form inside large clouds of gas and dust. The gases heat up and light and heat are created

Why do stars Twinkle? l Stars twinkle in the night sky because the light has to travel through the Earth’s atmosphere. The movement of air in the earth’s atmosphere make the light bend as it travels from the star to earth.

Which stars are brightest l Stars can have different colours such as red, white or blue. The hottest stars are blue, the coolest stars are red.

How many stars are in the universe? l There are over a hundred billion stars in the universe.

What shape are stars? Stars are not really star- shaped. They are round like out sun. l Artist draw them using a star shape to reflect the way that they shine in the night sky. l No two stars are exactly the same l

Constellations

Stars as Tools for Navigation v The North Star is called Polaris and located directly above the North Pole. This star appears in the same place every night all year long. v In the Northern Hemisphere, if you find Polaris you will be able to tell which direction is north. v. The Southern Hemisphere does not have a star to help you find its pole. Instead it has what is known as a Southern Cross. v The Southern Cross consists of 4 bright stars and some dimmer ones. All of these together point to the south pole.

Stars as tools for navigation l North Star l Southern Cross

A pattern or group of stars in the sky is called a constellation. People of ancient time saw the constellations as character or animals in the sky. They made up stories to explain how the object, animal, or character came into the night sky.

Star Patterns

The Big Dipper

Myth: The “Big Dipper” is a constellation. In fact, the Big Dipper is an asterism. l Constellations are used to split the celestial sphere into different sections that aid in locating objects in the sky, kind of like landmarks on a map. l An asterism, on the other hand, is a popular grouping of stars easily recognized by the casual star observer. Asterisms, which may be part of a recognized constellation, are not constellations themselves. The Big Dipper is an asterism in the constellation Ursa Major (the Great Bear).

In Ireland we call ‘The Big Dipper’ ‘The Plough’

Orion- The Hunter l This Constellation was named after the Greek hunter Orion and is one of the latgest groups of stars in the sky. l Orion is in the shape of a man holding a bow and is easily recognisable by the row of three bright stars that make up is ‘belt’

Taurus is located in the Northern Hemisphere, directly above Orion. l The Greeks saw this constellation as a bull l Taurus is one of 12 constellation that make up the zodiac l Astrologists believe that each person comes under a particular sign of the zodiac, depending on their date of birth l

I was born in December, I am a Sagittarius l What does your star sign constellation look like?

Constellations v Earth rotates on its axis, this makes most constellations appear to rise in the east and set in the west during the night. v Most constellations appear in many different positions in the sky as the Earth revolves around the sun. v There is a group of stars that appear in the sky all night long and all year long. It seems that these stars do not rise and set, but circle the Earth’s north pole each night. These stars are called circumpolar.

STAR CHARTS How can we identify constellations in the night sky? The use of a star chart can help us! A STAR CHART is a map of the stars in the night sky.

STAR CHARTS On a star chart, lines often connect the stars that might make up a constellation. Different star charts must be used at different times of the year and in different places on Earth. Many stars visible from the Southern hemisphere cannot be seen from the Northern hemisphere.

STAR CHARTS

What other tools can help us identify constellations? l STAR CHARTS are the BEST for identifying a constellation in the sky. l A COMPASS is the BEST for locating DIRECTION (North, South, East, and West) You need to know direction before you can use a star chart correctly.

What other invention helps us view items in space? l A telescope!

l l l l Star- large _____ of glowing _____ Constellations- a _____ or group of ______ in the sky Star Chart- _______ of the ______ in the night sky used as a way to identify constellations Compass- used to locate _____ in order to use a star chart _____ Telescope- used to see ______ away ____ in ____ up-close An asterism, which may be ____of a recognised______, are not _______themselves. ____ constellation that make up the zodiac.

l l l l Star- large sphere of glowing gases Constellations- a pattern or group of stars in the sky Star Chart- map of the stars in the night sky used as a way to identify constellations Compass- used to locate direction in order to use a star chart correctly Telescope- used to see far away objects in space up-close An asterism, which may be part of a recognized constellation, are not constellations themselves. 12 constellation that make up the zodiac