Birthday Stars

http://www.planet-science.com/categories/over-11s/space/2010/12/birthday-stars.aspx

Birthday Star

Use the Birthday Stars computer to find out your birthday star!

What's the best gift that you can get for your birthday? Chocolate, DVDs and clothes are all good gifts, but what if you could get your very own star? That would be brilliant!

Whilst you might not be able to buy your own star (yet), the Birthday Stars computer will look for a star that is your age in light years away from the Earth. This means that the light we're seeing from the star today actually left the star around when you were born and has taken your entire life to reach Earth. Amazing! Try it here:


http://outreach.jach.hawaii.edu/birthstars/

Birthday Stars    What's this all about?

Light travelling in empty space is the fastest thing in the universe. It travels at 186,000 miles per second!
The stars are so far away from us that their light still takes a long time to reach Earth. One light year is the distance light travels in a year: 5,878,499,812,499 miles. The closest star apart from the Sun is 4.2 light years away, so its light takes 4.2 years to reach Earth.
Tell the Birthday Stars computer when you were born, and it will look for a star that is your age in light years away from Earth. This means that the light we're seeing from that star today actually left the star around when you were born, and has taken your entire life to reach Earth.
From month to month you may see your birthday star changing. This is because as you get older the light from more and more distant stars has had the time to travel to Earth in during your life.