590 likes | 729 Views
The life cycle of Stars. Where do stars come from. Stars form in clouds of gas (a nebula) These are called diffuse nebula or star forming nebula. A single nebula can form hundreds or even thousands of stars Let’s see what they look like!!. M8 – The Lagoon Nebula. M16 – The Eagle Nebula.
E N D
Where do stars come from • Stars form in clouds of gas (a nebula) • These are called diffuse nebula or star forming nebula. • A single nebula can form hundreds or even thousands of stars • Let’s see what they look like!!
M8 – The Lagoon Nebula M16 – The Eagle Nebula Star Forming Regions
What do new stars look like • New stars usually have • Polar jets of gas and dust • A dark disk of material around its equator • They shine brightly in infrared but not visible light because the cloud of gas that the star forms from is blocking some light
What happens when stars start forming in nebulas • Stars often form in groups called “clusters” • There are two types of clusters 1. Open Clusters usually have only a few hundred or a few thousand stars 2. Globular Clusters have hundreds of thousands of stars or even millions of stars
Open Cluster - M45 The Pleiades – The Seven Sisters
Open Clusters • Open clusters are still forming today from the larger gas clouds • Our Sun formed most likely was born in an open cluster • Open clusters are found inside our galaxy • The gravitational attraction between the stars in an open cluster is not strong enough to hold the cluster together, so the stars go their separate ways and live individual lives
M3 M5
Globular Clusters • Properties of Globular Clusters: • They contain so many stars that gravity keeps the cluster intact • GC’s must have formed early in the universe when the clouds of gas were much larger and could produce more than a million stars at one time • No GC’s are forming today! • GC’s contain many of the oldest stars in the universe • GC’s are found in a halo surrounding the nucleus of our galaxy
Globular Clusters Open Clusters
What happens at the end of the stars life? • Average stars produce planetary nebula • When the core of the star starts a fusion reaction with the helium ash, the temperature increases dramatically causing the outer layers to be puffed off. • Massive stars produce supernova explosions • When larger stars start to produce iron at their core, it marks the beginning of the end. The core collapses and then rebounds in a massive explosion called a supernova!
A glimpse at our future M57 – The ring Nebula
NGC 7293 – The Helix Nebula A close up view
This star is in the large Magellanic cloud and became visible to the naked eye in 1987 but it actually exploded about 180,000 years ago