Transcript Stars

A star is a sphere of hot gas that emits light and
We see different constellations
the year because different portions of the
universe are visible to us during that time (
the Earth revolves around the sun)
We use light years to determine the
distance to stars
All energy from stars comes from
thermonuclear reactions (fusion)
in the core
Fusion is 2 small atomic nuclei joining to form one atom
Life of a star
All stars are held together by gravity**
The Hertzsprung – Russell diagram
Our sun is an average,yellow,main sequence star
• All the energy the sun provides to the
Earth was previously contained in the
atoms of the sun.
• All stars radiate light, heat, and
electromagnetic waves
• The brightness of a star is determined
by the size, distance, and
• The electromagnetic spectrum contains all
the transverse waves in order of their
wavelength and frequency:
• Radio, infrared, visible, ultraviolet, x-rays,
gamma rays