Physics 8.1.4 Flashcards
What are the Stages in the Life Cycle of a Solar Mass Star? Explain each step. (7)
-Nebula: Giant Cloud of Hydrogen Gas & Dust. Core of Gravity.
-Protostar: The Inward Force of Gravity from the Core Pulls the Particles Closer Together, until it Forms a Hot Ball of Gas, known as a Protostar.
As the P.cles are Pulled Closer Together, the Density of the Protostar will Increase. So more Frequent Collisions between the P.cles, so the Temp, will Increase More.
-Main Sequence Star: Once the Star becomes Hot enough, Nuclear Fusion Reaction Occur within its Core.
Hydrogen Nuclei partake in Nuclear Fusion to form Helium Nuclei.
Each Nuclear Fusion Reaction Releases Heat & Light Energy, which keeps the Core ever-expandingly Hot.
Main Sequence Stars are what we would regularly refer to as Stars, in the night sky. The Sun is a Star.
-Red Giant: After several Billion Years, the Hydrogen Nuclei in the Core will Run Out.
Hence, the Nuclear Fusion in the Core will start to Die Down.
Hence, the Core Shrinks, & Heats Up.
It Shrinks because now that there is v. Little Nuclear Fusion Occuring in the Core, Little Outward Force of Pressure is being Produced. So, now Inward Force of Gravity > Outward Force of Pressure. Hence, the Core Shrinks.
Then, the Helium Nuclei will start to Undergo Nuclear Fusion, & Form Beryllium.
These Nuclear Reactions will Cause the Outermost Part of the Star to Expand.
It will become a Red Giant.
It is Red because the Outermost Surface Starts to Cool.
-Planetary Nebula: Once the Helium Nuclei Run Out, & their Nuclear Fusion Stops, the Star will becomes Unstable (due to immense imbalance of Inward Force of Gravity > Outward Force of Pressure), & so eject the Outermost Layer of Dust & Gas.
-White Dwarf: The Core which is Left behind will Collapse completely, due to the Pull of Gravity it Performs upon Itself, & the Star will become a White Dwarf.
The White Dwarf will Start to Cool Down, and, as a result, the amount of Energy it Emits will Decrease.
-Black Dwarf: Once the Star has Lost lots and lots of Energy, it becomes a Black Dwarf.
It will continue to Cool (& so loose more & more Energy), until it Eventually Disappears from Sight.
What is a ‘Solar Mass Star’?
A Solar Mass Star is a Star with a Similar Mass to that of our Sun.
