Back in Time

Do you ever find yourself looking back at the past trying to remember things that happened and decisions that you made or perhaps where you were when that really famous event happened?

Sometimes when I look up at the night sky and see the stars I think like that. Today I had cause to talk about the Sun and the stars and how looking at them is a little like looking back in time. The Sun is just over 90 million miles away. The light from the Sun takes 8 minutes to travel to my eyes on the Earth. Nothing travels faster than the speed of light. This means that when I look at the Sun I am looking at the light it produced eight minutes into the past. I'm looking back in time. If the Sun suddenly went out now...we wouldn't know for 8 minutes.

http://www.seasky.org/constellations/assets/images/pegasus.gif


Today I found a very special star system. It is called 85 Pegasi A/B. It is a multiple star and can be found in the constellation of Pegasus. Star A is very much like our Sun and star B is an orange dwarf. These are not the only stars that seem to be orbiting each other.

What is important about Pegasi A/B is the distance it is from the Earth. It's distance has been calculated as 40.5 light years away. This means that light from this star system takes 40.5 years to reach the Earth. This means tat light arriving on the Earth now originated from the star system about the day I was born. Looking up at that star is like looking back at the beginning of my now middle aged self. A humbling thought indeed.

 

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