How Big Are Stars?

When we look up in the night sky on a clear night we see lots and lots of stars and they look like tiny dots of light.  But they are all different sizes and different distances from us.  But they all look tiny.

To put the sizes in perspective the following are some diagrams of 4 different large star shown in comparison to the size of the planets of our solar system in their orbits.

Deneb is a white super giant and is 60,000 times as luminous as our Sun.  It is about 1,500 light years away, which means that when we look at it, the light that we see left that star in the year 500 A.D. and has been traveling these 1,500 years to reach the Earth.

Deneb is found in the northeastern summer sky (to the right of the North Star) in the constellation Cygnus, the Swan.  It is also part of a group of stars known as the Northern Cross and it's a very bright star in the northern sky.

If Deneb were in the center of our solar system, it would swallow up Mercury and come very close to Venus.  It's about 150 times bigger than the Sun.


A bit of a disclaimer:  the dimensions of these stars were found on the internet and different sites have different diameters listed for some of the stars.  So the drawings may not be completely accurate.  The purpose of these diagrams is to show the extraordinary scale of some of the things we share this universe with, so if the dimensions are off somewhat, the magnitude and enormity of these stars is still demonstrated.  Thanks for understanding.

Betelgeuse (pronounced "beetle juice") is a red super giant and it is the right shoulder in Orion in the southern winter sky.  It is 500 light years away, meaning that the light we see today left the star about the time Columbus was sailing to America. 

Betelgeuse is in the constellation Orion.  It's Orion's right shoulder.

If Betelgeuse were at the center of our our solar, its surface would extend out to between the orbits of Mars and Jupiter.  It is about 650 times bigger than the Sun.


The scale of these diagrams is increasing, otherwise they would be bigger than this page.

If you watch the orbit of Mars you'll see it appears smaller as the scale of the diagram increases.  You'll also notice that the stars from previous diagrams are included.

Antares is a red super giant in the constellation Scorpio, in the summer southern sky.  It is 600 light years away, so it's light left 100 years before Columbus' discovery.

Antares is in the middle of the constellation Scorpio in the summer sky.

Antares is almost 1,000 times bigger than the sun and if were in the center of our solar system it would reach almost out to Jupiter.


But Antares isn't the largest known star.  One of the very largest stars known, and the largest in the Milky Way, is V V Cephei.  It's about 3,000 light years away, so its light was traveling toward us for 1,000 years before Christ was even born.

It is about 1,900 times bigger than the Sun and is approximately 400,000 times brighter.  It is in the constellation Cepheus, not too far from the North Star.

If it were in the center of our solar system it would engulf Mercury, Venus, Earth, Mars, Jupiter, and almost reach Saturn.  Now that is hyper giant for sure.