Classification of Stars (Review)

What is the current size of the Sun classified as?

• Red Giant Phase

• Main Sequence

• Blue-White Super Giant

• White Dwarf

Answer explanation

The Sun is currently in the Main Sequence phase, where it fuses hydrogen into helium in its core. This phase is characterized by stable luminosity and size, distinguishing it from other stages like Red Giant or White Dwarf.

Which of the following is a characteristic that stars differ in?

• Shape

• Mass

• Distance from Earth

• Orbit

Answer explanation

Stars differ in mass, which affects their brightness, temperature, and lifespan. While distance from Earth varies, it does not characterize the stars themselves. Shape and orbit are not distinguishing features of stars.

What characteristic of a star is related to how bright it appears?

• Size

• Temperature

• Luminosity

• Color

Answer explanation

Luminosity refers to the total amount of energy a star emits per second, which directly affects its brightness as seen from Earth. Therefore, luminosity is the key characteristic related to how bright a star appears.

Which characteristic of stars is associated with their heat?

• Mass

• Size

• Temperature

• Luminosity

Answer explanation

The temperature of a star is directly related to its heat. Higher temperatures indicate hotter stars, while lower temperatures correspond to cooler stars. Thus, temperature is the characteristic associated with a star's heat.

Stars can differ in color. What does this indicate about a star?

• Its age

• Its distance

• Its temperature

• Its size

Answer explanation

The color of a star indicates its temperature. Hotter stars appear blue or white, while cooler stars appear red or orange. Therefore, the color difference directly reflects the star's temperature.

What are the main gases that make up a star?

• Oxygen and nitrogen

• Hydrogen and helium

• Carbon dioxide and methane

• Neon and argon

Answer explanation

Stars are primarily composed of hydrogen and helium, which account for about 98% of their mass. Other gases like oxygen and nitrogen are present in trace amounts, making hydrogen and helium the correct answer.

Tags

NGSS.HS-ESS1-1

What characteristics do bigger stars have compared to smaller stars?

• Less mass, less gravity, and cooler

• More mass, greater gravity, and hotter

• Same mass, same gravity, and same temperature

• Less mass, greater gravity, and cooler

Answer explanation

Bigger stars have more mass, which leads to greater gravity and higher temperatures due to increased nuclear fusion in their cores. This distinguishes them from smaller stars, which are less massive, have lower gravity, and are cooler.

What type of stars are classified as large stars?

• Giants or Super Giants

• Main Sequence

• White Dwarf

• Neutron

Answer explanation

Large stars are classified as Giants or Super Giants due to their significant size and luminosity compared to other types of stars. Main Sequence stars are not classified as large, while White Dwarfs and Neutron stars are remnants of smaller stars.

Which category does the Sun belong to in terms of star size?

• Large Stars

• Medium Stars

• Small Stars

• Neutron Stars

Answer explanation

The Sun is classified as a medium star, specifically a G-type main-sequence star (G dwarf). It is not large like supergiants or small like red dwarfs, and it is not a neutron star, which is a completely different category.

What are small stars classified as?

• Giants

• Main Sequence

• White Dwarf or Neutron

• Super Giants

Answer explanation

Small stars, after exhausting their nuclear fuel, can become white dwarfs or neutron stars. These are remnants of stars that were once in the main sequence phase, but are no longer undergoing fusion.