What is a Constellation?
➢ A group of stars that, when seen from Earth, forms a pattern.
➢ The International Astronomical Union (IAU) is responsible for naming and classifying
celestial objects, including constellations
○ There are 88 constellations listed to date
➢ In ancient times, people created stories about mythological creatures and characters which they
associated with constellations.
➢ As astronomers subsequently began to make maps of the stars, the named constellations were
included in the maps
Constellations
➢ The constellations that you are able to see in the sky depend on:
○ The earth’s revolution around the sun. At different times of the year, you see different
constellations.
○ Latitude of where you live
The Big Dipper
➢ One of the most visible star patterns in the northern sky is The Big Dipper
➢ The Big Dipper’s two end stars are called the pointer stars because they point toward
Polaris, the North Star.
Polaris
➢ The North Star
➢ Used by people in the northern hemisphere to tell direction
○ If you can see Polaris, then you know which way is north
➢ Earth’s rotational axis points to Polaris, so as earth rotates eastward on its axis, Polaris
does not appear to move, unlike other stars
Constellations-Random Stars
➢ When we see the stars in constellations from earth, they appear to be close to each other
➢ In fact, stars in constellations are unrelated in space.
○ Distant from each other-they may actually be light years apart
Stargazing
➢ Star maps show you the relative locations of stars in the sky at a certain time of night on a
certain date.
➢ The larger the dot on the star map, the brighter the star is.
➢ We use the term apparent magnitude to describe the brightness of a star, as seen from
earth.
➢ A group of stars that, when seen from Earth, forms a pattern.
➢ The International Astronomical Union (IAU) is responsible for naming and classifying
celestial objects, including constellations
○ There are 88 constellations listed to date
➢ In ancient times, people created stories about mythological creatures and characters which they
associated with constellations.
➢ As astronomers subsequently began to make maps of the stars, the named constellations were
included in the maps
Constellations
➢ The constellations that you are able to see in the sky depend on:
○ The earth’s revolution around the sun. At different times of the year, you see different
constellations.
○ Latitude of where you live
The Big Dipper
➢ One of the most visible star patterns in the northern sky is The Big Dipper
➢ The Big Dipper’s two end stars are called the pointer stars because they point toward
Polaris, the North Star.
Polaris
➢ The North Star
➢ Used by people in the northern hemisphere to tell direction
○ If you can see Polaris, then you know which way is north
➢ Earth’s rotational axis points to Polaris, so as earth rotates eastward on its axis, Polaris
does not appear to move, unlike other stars
Constellations-Random Stars
➢ When we see the stars in constellations from earth, they appear to be close to each other
➢ In fact, stars in constellations are unrelated in space.
○ Distant from each other-they may actually be light years apart
Stargazing
➢ Star maps show you the relative locations of stars in the sky at a certain time of night on a
certain date.
➢ The larger the dot on the star map, the brighter the star is.
➢ We use the term apparent magnitude to describe the brightness of a star, as seen from
earth.
