Star Lesson

Stars

Properties of Stars

How do we classify them?

Open Ended

What are some things you know about stars?

Watch: How a Star is Born

https://www.youtube.com/watch?v=mkktE_fs4NA

Multiple Choice

All stars begin their life in a

• Main Sequence

• Nebula

• Protostar

• Black Dwarf

Multiple Choice

Most stars are made of which elements?

• Hydrogen only

• Hydrogen and Lithium

• Hydrogen and Sodium

• Hydrogen and Helium

Multiple Choice

Which might change, depending on the DISTANCE to a star?

• Absolute Brightness

• Apparent Magnitude

Multiple Choice

If a scientist needs to calculate the luminosity of a star, what information would they need?

• Distance

• Apparent Magnitude

• Temperature

• Distance and Apparent Magnitude

Poll

Two stars are being compared. Star A has a greater luminosity than Star B. Star A and Star B have the same apparent magnitude. WHICH STAR IS MORE DISTANT?

• Star A

• Star B

Multiple Choice

The H-R diagram classifies stars based on what factors?

• Temperature and luminosity

• Number of planets

• What constellation they're in

• Temperature and fusion

Let's Think...

• Stars A & B have the same apparent magnitude in the sky.

• Can we assume that they have the same absolute brightness? Why or why not?

• What if, star A is 50 LY away & star B is 10 LY away? Which one has the highest luminosity?

Multiple Choice

Stars that are brighter are usually...

• Hotter

• Bigger

• Smaller

Multiple Choice

Which star is the coldest?

• Yellow Star

• Red Star

• Orange Star

• Blue Star

​H-R Diagram

​We classify/organize stars on the Hertzsprung-Russell diagram OR HR Diagram.

​

​Astronomers sort stars by their:

​

1. ​Temperature

2. Size or Mass

​

​Both temperature and size/mass of a star help us understand the ABSOLUTE BRIGHTNESS or how bright a star actually is.

Multiple Choice

Our sun is yellow. A star colder than our sun would be...

• Red

• Yellow

• White

• Blue

Multiple Choice

What two quantitative measurements do we use to measure absolute brightness?

• Temperature and Color

• Color and Mass

• Temperature and Mass

Multiple Choice

Compared to a red giant star, a blue supergiant is...

• Hotter and brighter

• Hotter and not as bright

• Colder and brighter

• Colder and not as bright

Multiple Choice

Our sun is what kind of star?

• Blue giant

• Red giant

• Main sequence

• White dwarf

Multiple Choice

Blue stars are the _____________.

• hottest

• coolest

• smallest

Multiple Choice

Which is the correct order of stars from COOLEST to HOTTEST?

• blue, white, yellow, orange, red

• red, yellow, blue, white, orange

• red, white, yellow, orange, blue

• red, orange, yellow, white, blue

Multiple Choice

Which of the following is NOT a characteristic used to classify stars?

• Color
• Temperature
• Size
• Shape

Multiple Choice

Which Star is the HOTTEST?

• Blue

• Red

• Orange

• Yellow

Multiple Choice

Infer:

Naos is a star in the Argos constellation. It has a very deep Blue color. What do you think is the approximate temperature of Naos?

• Between 3,000 K - 5,000 K ( it is a cool star)

• Between 25,000 K - 50,000 K ( it is a hot star)

Multiple Choice

Which Star is the COOLEST?

• Blue

• Red

• Orange

• Yellow