APOD 3.3

Zeta Oph: Runaway Star (4 Feb. 2011)

This picture is of a runaway star named Zeta Oph, which can be located in the constellation Ophiuchus. A runaway star is a massive star that travels rapidly through interstellar space. Because it is rapidly traveling throught interstellar space at 24 km/sec, Zeta Oph created the arcing interstellar bow wave or bow shock seen in the picture. That is the orange/reddish arc that can be seen in the center of the picture. Zeta Oph is the blue shining point that is located in the arc. As seen from this picture, it should be moving towards the top of this frame. This star is moving through interstellar material. Interstellar material is the material which fills the space between the stars. These areas have very little matter in them and mainly consists of gas and dust, which is what we've learned about in class. There may be a small amount of dust particles per cubic cm, but with the great distances between the stars, the number of dust particles really add up.

With Zeta Oph, it has strong stellar winds that precede it. These winds compress and heat the dusty interstellar material and shapes the curved shock front. 

The thing that actually started to make this a runaway star was the explosion of its companion when it was in a binary star system. Because it's  companion star was much larger, it had a shorter life span. A star's life cycle is determined by its mass. The bigger it is the shorter its life cycle. When it's companion exploded as a supernova, this explosion propelled Zeta Oph through the system. It was actually flung 460 light-years away and it is actually 65,000 times more luminous than the sun. However as we learned that the numbers of dust particles add up through space and dust is like fog, this explains why this dust surrounded star isn't one of the brightest in the sky.