Physical Properties of Stars - PartTwo

Stars incredible because they are light years away from Earth, but yet we can still see their brightness every clear night. All stars have certain properties, or characteristics.

Properties/Characteristics:

1. Brightness - the amount of light the star radiates (luminosity) taking into account its size and distance from Earth (magnitude).

Properties/Characteristics:

2. Color - the star’s color is based on surface temperature: cooler stars are redder, hotter stars are bluer, mid range temperatures are white or yellow.

Properties/Characteristics:

3. Surface Temperature - measured on the Kelvin scale, the coolest reddest stars are around 2,500 K while the hottest stars can reach 50,000 K (The Sun is about 5,500 K).

Properties/Characteristics:


4. Mass - measured in terms of the Sun, called Solar mass. If a star is larger than our Sun, it might have a mass of 7.5 solar masses.

Properties/Characteristics:


5. Size - measured by the Sun’s radius (1 solar radii is the same size as the sun).

Properties/
Characteristics:

Properties/
Characteristics:

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​Protostar - how a star begins. It is a bunch of gas that has collapsed from a giant cloud. This phase could last 100,000 years.

​Main Sequence Star - Most stars in our galaxy are main sequence stars, including our Sun. They all convert hydrogen into helium by releasing a lot of energy.

Properties/Characteristics:

​Neutron - Unlike most stars that become a white dwarf to die, it dies in a 8 supernova explosion and the core that remains is a neutron star. It is made entirely of neutrons.

A few things to keep in mind is that one star’s lifetime could be many types of stars and change colors. Over time, a star eventually dies. It may take billions of years, but a star that begins as a dwarf star may change into a supergiant. Each star has a unique life cycle and transition to different stars.

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