Cannon 60D in bulb mode

I have a Cannon 60D that im using for Astrophotography. When i put it on a Telescope and have it in Builb it shows an aperture of F00. i can highlight the aperture but i can't change it. I use the wheel on the back and the one by the shutter button and still can't change it. I don't know enough about these cameras. If the telescope is 6.9, doesn't the camera need to know that or is it taken care of with the telescope?

Thanks in advance for the help.
Wayne

The camera can control the aperture of the lens, but only with EF-compatible lenses...if you mount a manual adjustment lens from the SLRs of the 1960-1980s it has zero control of the aperture of the lens. It shows f/00 because the lens does not communicate back to the body what the selected aperture of the lens at time of exposure is set to ...it does not communicate back what the selected aperture for exposure is set to. It is the lens which tells the body 'max aperture = f/(max), selected aperture = f/n, so the camera understands for the purposes of displayed exposure values.
Same thing for a telescope as happens with a non-EF lens.

Thank you for the information.