1. STARS

2. Tritium and Deuterium are two types of hydrogen.
Stars are enormous balls of very hot _____, mainly ________ and ______. They are fueled by a process called ______________. In this process, hydrogen atoms are fused together to make helium. This fusion releases a large amount of _______. The energy powers the heat and light of a star.
gases
hydrogen
helium
nuclear fusion
energy
Tritium and Deuterium are two types of hydrogen.

3. The stars in our night sky are not all the same ____
The stars in our night sky are not all the same ____. Some appear white or blue, and others appear red, orange, or yellow. The color of a star can tell us about the ____________ of a star and about the elements that make it up.
color
temperature
It is hard for us to distinguish between the star colors because the cones in our eyes that distinguish color to not work well in low light.

4. Scientists use a _____________to separate the visible light that comes from objects (like stars and nebulae) into different colors according to their ____________. The spectrum we see from a star is not a continuous spectrum; instead it has ___________ lines on it. .
spectrograph
wavelength
absorption

5. “composition ___________.”
The absorption lines can teach scientists about the composition of ______ that make up a star. Each star has its own
“composition ___________.”
gases
fingerprint

6. Scientists classify stars by their surface ____________
Scientists classify stars by their surface ____________. The _____ of a star reveals its temperature. The _____ stars are the hottest at over 30,000 degrees Celsius. The ____ stars are the coolest at approximately 1,500 degrees Celsius. Let us look at the classification of stars from the hottest to coolest.
temperature
color
blue
red

7. Class __ are the ________ stars
Class __ are the ________ stars. They are _____ in color and are the rarest and the most ________. The surface temperature is over 30,000º C. O
hottest
blue
massive

8. Rigel
Class __ stars are the next hottest. They are ____________ in color and are 2 to 16 times the mass of our Sun. The surface temperature can range from 10,000-30,000ºC. B
bluish-white

9. Next, the Class __ stars are also a ___________ color
Next, the Class __ stars are also a ___________ color. The surface temperature is from 7,000-10,000º C. A
bluish-white
Sirius, the brightest star in the sky. It is the 6th closest star to Earth.

10. Class __ stars are a _________ ______ color and have from 1 to 1
Class __ stars are a _________ ______ color and have from 1 to 1.4 the mass of our Sun. The surface temperature is from 6,000-7,500ºC. F
yellowish-
white
Canopus

11. Class G stars are _______ and are sometimes called a ____________
Class G stars are _______ and are sometimes called a ____________. Our Sun in a G-type star. The surface temperature can range from 5,000-6,000°C.
yellow
yellow dwarf
Alpha Centauri

12. Class __ stars are _______
Class __ stars are _______. These stars are slightly ______ than our Sun. The surface temperature is 3,500-5,000°C. K
orange
cooler
Arcturus

13. The class __ stars are the _______ stars. They are ____ in color
The class __ stars are the _______ stars. They are ____ in color. These are the most ________ type of star in the galaxy. The surface temperature is 1,725-3,500°C. M
coolest
red
common
Betelgeuse

14. To help remember the order of stars from hottest to coolest, remember this:
Fine
Girl, (Guy),
Kiss
Me!

15. http://science. nationalgeographic