Properties of Stars Notes

• Describe that stars are classified by physical properties

including temperature (color), size, and brightness.

• Compare and contrast a star’s apparent magnitude with

its absolute brightness.

• Explain how color of a star relates to its temperature.

OBJECTIVES:

1. Intro to Stars
Video
2. Properties of
Stars Notes
3. Blooket or Quizizz

Today’s Agenda:

Properties of Stars Notes

Write the answers only!

1. What is name of the

dust and gas that
forms a star?

2. What force draws

particles together
and creates a star?

Gravity pulls dust and gas (nebula) together over
millions of years to make a new celestial body

Properties of Stars Notes

- Most stars are made up of hydrogen and helium (burning

gas)

- Scientists classify/organize stars based on COLOR, SIZE, and

BRIGHTNESS

1. SIZE:

- Largest = supergiants
- Medium= “main sequence.” The sun

is a main sequence star.

- Smallest = dwarfs.

Compare our star to others in the
universe….

2. BRIGHTNESS:

- Depends on the size and temperature of a star.

- The brightest stars are the largest and hottest.

A

B

C

D

E

Which light appears
to be brighter???

- Apparent magnitude (brightness); how bright the star

seems (or appears) from Earth.

- Brighter star = closer to Earth.

This star APPEARS bright

- Absolute Brightness (Luminosity) = The actual brightness is

measured by the apparent magnitude and the distance

from Earth

3. Temperature = color

- Blue = HOTTEST stars.
- Orange/yellow = MEDIUM temperature.
- Red = COLDEST stars.

Q#1: Which is hotter? Lighter or blow torch?

Q#2: Which star is the hottest???