Download Groups of Stars

GROUPS OF STARS
WARM UP
• Compare the life of a star to the life of a human.
Describe how the life stages are similar. You will
need to choose the life cycle of either a lowmedium mass star OR a high mass star.
CONSTELLATIONS
• Groups of stars that appear to form a pattern as
seen from Earth
• These stars aren’t necessarily close together,
they just happen to lie in the same general
direction as viewed from Earth
STAR SYSTEMS
• Many stars exist in groups of two or more stars
that are held close together because of gravity
• More than half of all stars are members of star
systems
• Is our Sun part of a star system?
STAR CLUSTERS
Pleiades – all of these stars formed together in the
same nebula, they are all about the same age and
distance from earth.
STAR CLUSTER
• A group of stars that formed from the same
nebula
• This means they formed at about the same
time and they are all about the same distance
from Earth
GALAXIES
GALAXIES
• Huge groups of individual stars, star systems, star
clusters, dust and gas bound together by gravity
• Four types of galaxies
• Spiral
• Barred-Spiral
• Elliptical
• Irregular
SPIRAL GALAXIES
BARRED-SPIRAL GALAXIES
ELLIPTICAL GALAXIES
IRREGULAR GALAXIES
MILKY WAY GALAXY – FROM EARTH
MILKY WAY GALAXY FACTS
•
Contains 200 – 400 billion stars
•
Over 100,000 light years across
•
Average thickness is 10,000 light years, but its 30,000 light years in the center
•
Every star you can see with the unaided eye is in the Milky Way galaxy
•
The Sun is in one of the spiral arms about 2/3 of the way (or about 27,000 light
years) from the center of the galaxy
•
The sun orbits once around the Milky Way every 220 million years
•
At the center of the Milky Way is a bulge of stars surrounded by star clusters
•
Stars are forming out of dust in the spiral arms
•
The next closest galaxy is Andromeda, 3 million light years away (THIS GALAXY IS
MOVING TOWARDS THE MILKY WAY, THEY WILL EVENTUALLY COLLIDE!!! This
event will occur in about 5 billion years…)
•
What's REALLY at the center of the Milky Way?