Black Hole Particle System in Cascade?

Hi,

I’m fairly new to cascade editor and I was wondering how could I go about creating a particle system resebling the one seen in the video below. I don’t want the center of the hole to be a black mesh, though- I was thinking about maybe making it a little bit refractive. I also want the stars visible, but blending in with the blueish vortex. Those things I more or less know how to achieve, the refraction is explained in a live training from a week back, and the stars are pretty basic. What I don’t know is how do I get the “sucking in” effect going. I was thinking about somehow reversing the flow of particles (I don’t know how though), or placing the origin of the particles on the outside, in a circle (still,no idea how). Alternatively I think it can be also done with vector fields, but again, I have no idea how to go about that. Any help as to choosing the right (easiest) way is appreciated.

Cheers,
Mike