Polaris the North Star

Michelle Hollon

Polaris is a Star System

When you see Polaris it isn't just a star, but a star system. The primary star is Polaris A. Polaris A is what we can see from Earth. Polaris A is a supergiant that is six times the amount of mass of our sun. about 2 billion miles away is the next star in the system, Polaris Ab. Even farther away, about 240 billion miles from Polaris A, is Polaris B. Polaris Ab and Polaris B both have the same temperature as Polaris A but are dwarf stars.


Polaris is older than 2000 years old but we cannot be sure of its age. It has the luminosity of about 2500 suns, which is why we can see it so clearly. It is also 430 light years away. Polaris is about 6 solar masses. The two smaller stars are about a 1.5. Polaris is 6000 K. Which also factors in how we can see it clearly and how it is so bright.

Life Cycle of Polaris

Please note that I have used exact definitions as well as my own word in the following:


Just like every star, Polaris started out as a nebula. A nebula is an interstellar cloud of dust, hydrogen, helium, and other ionized gases.

Nebulas can be formed in more than 1 way, most are formed by the gravitational collapse of gas in the interstellar medium. As i collapses under its own weight stars form in its center. The stars ultraviolet radiation ionizes surrounding gas. The size depends on the size of the original cloud if dust.

Some are formed by supernova explosions. Materials thrown off by the explosions are ionized by energy for the object that it can produce.

Others form as planetary nebulae, the final stage of a low-mass star's life. When the dying star loses enough material, its temperature increases and ultraviolet radiation produced can ionize surrounding nebulae that it has thrown off.


The next step Polaris took was it became a protostar. A protostar is a contracting mass of gas that represents an early stage in the formation of a star before nucleosynthesis has begun. A protostar looks like a star but its core is not hot enough to be an actual star. A protostar is formed when a gas cloud collapses and begins to spin. By time, a protostar is formed.

A protostar becomes a main sequence star when its core exceeds 10 million K.


A main sequence star is the next step a star takes in its life cycle. A main sequence star is what 90 percent of stars are. What a main sequence star is, is a star that is fusing hydrogen atoms to form helium atoms in its core.


After the main sequence, a star can split off into either a red giant or red supergiant. Polaris is a supergiant.

A supergiant is the exact same thing as a giant star only much larger.


Once Polaris is through being a supergiant it will move on to be a supernova.

A super nova is the point in the stars life that it emits as much energy and luminosity as it does through its entire life span before fading out. After this short period of time of being a super nova, Polaris will eventually die.


I chose Polaris to die as a black hole.

A black hole is the end of a Stars life. It has such a strong gravitational pull that nothing in existence can escape from it.

How Polaris will die

Below are pictures of the life cycle of Polaris. I have chosen for polaris to die as a black hole. Polaris could have died as a meutron star but I chose the black hole instead.
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