There were some stars there, but some were added as well. The way motion blur works is that, the closer things are to you, the more they blur, the further away, the less. To get the stars to blur you'd have to be traveling faster than the speed of light
Haha, glad to hear You're not the first person to ask about it actually. Funny thing is, the stars weren't my idea, they were actually there in the original shot, I just added more because I liked the look .