STARS

Like our Sun, stars are massive globes of intensely hot gas. They produce huge amounts of energy, which is given off as heat and light. The bright stars form patterns, which we call the CONSTELLATIONS. All the stars lie so far from Earth and from each other that the distances are measured in light years. The light from our nearest star, Proxima Centauri, takes over four years to reach us. This means it lies over four light years away.

STAR SIZES

Stars vary widely in size. Our Sun is quite a small star, known as a yellow dwarf. Red giant stars are typically 30 or more times bigger in diameter than the Sun and supergiants are hundreds of times bigger. In contrast, the Sun is 100 times bigger than the tiny dense stars called white dwarfs.

DISTANCE TO THE STARS

If you hold up a finger and look at it with first one eye, then the other, your finger appears to move in relation to objects in the background. This happens because your line of sight from each eye is slightly different. The effect is called parallax. In the same way, as Earth orbits the Sun, our line of sight to the stars changes. Nearer stars shift relative to those further away. Astronomers measure the shift of a star’s position at different times of year and can then calculate how far away it is.

CONSTELLATIONS

Many stars form patterns that we can recognize. We call these patterns the constellations, and many of them are named after real or mythological animals. Astronomers recognize 88 constellations, and divide the sky up into areas around each constellation. Although the groups of stars appear to be close together, they can be hundreds of light years apart. From Earth, they just appear to be grouped because they all lie in the same direction in space.

ORION IN THE SKY

The constellation Orion is one of the most easily recognizable in the heavens. It straddles the celestial equator, so it can be seen well by observers in both the Northern and Southern Hemispheres. Northern observers see it best in winter skies and southern observers in summer skies. Betelgeuse and Rigel are its brightest stars.

MIGHTY HUNTER

The constellation of Orion takes its name from a great hunter in Greek mythology. To early astronomers the pattern of the brightest stars looked like a hunter holding a club. The three stars in the middle make up Orion’s Belt. The Orion Nebula forms part of the sword that hangs from his belt.

Copyright © 2007 Dorling Kindersley

stay connected

Sign up for our free email newsletters and receive the latest advice and information on all things parenting.

Enter your email address to sign up or manage your account.

Facebook icon Twitter icon Follow Us on Pinterest

editor’s picks

highlights

Join BIC on our mission to save handwriting and Fight For Your Write! Writing helps kids become better readers, boosts their confidence and sparks their creativity. Visit BICFightForYourWrite.com to sign our petition to save handwriting!

7 Fun Driveway and Sidewalk Games for Kids
Looking for classic outdoor games kids can play in the driveway or on the sidewalk, just like the good ol' days? From hopscotch to bubble-blowing contests, there's something for all ages!

Kindergarten Readiness App Wins Gold
Our Kindergarten Readiness app won the Gold Award of Excellence in the educational category at the 2014 Communicator Awards. This valuable checklist comes with games and activities to help your child practice the essential skills she needs for kindergarten. Download the Kindergarten Readiness app today!

Best Sun Safety Practices for Babies
Follow these sun safety practices for babies to ensure your little one stays safe on the beach and on sunny days all year long.