This is a "track and stack" image. It consists of about 20 images taken on Wednesday 8th October 2008. The images are centred on the asteroid itself, hence the stars are all trailed. This technique was necessary to show the asteroid itself which at a magnitude of about 19.9 is very faint.
Brief details of asteroid 2008 TM9 that we have at the moment are that it is a main-belt asteroid and orbits the sun between Mars and Jupiter. It has a diameter between 2 and 4km.
You can see an orbit animation and further details here (Java required).
As a main-belt asteroid, we can rest assured that it won't be visiting Earth any time soon.