Stars

On a clear, moonless night, well away from city lights, you can see about 4,000 stars. Remember that every star is in fact a sun, comparable to our own sun, although many stars in the night sky are actually more luminous than the sun.

Star colors
Stars have different colors. Look closely, and you will see that some are yellowish or orangish, while others are whitish or bluish. A star's color betrays its surface temperature: red and orange stars are cool (approximately 3,500 degrees Centigrade), while white and blue stars are hot (over 10,000 degrees).