Is Canon EOS 20D Astrophotography and Nikon AF-S DX 40mm f/2,8 G Micro compatible?

Below you will find your chosen camera and lens. Click on the product name for more information.

Buy	Canon EOS 20D Astrophotography Released: 2005 Type: Digital SLR Sensor: APS-C (1.6x) 8,2 Megapixels 3504 x 2336 pixels
Buy	Nikon AF-S DX 40mm f/2,8 G Micro Released: 2011 Normal Lens (prime) & Macro Suited for cameras with APS-C sensors Focal Length: 40 mm Aperture: f/2,8

Can you combine these two?

This is the short answer:

No! This combination is not compatible

The camera and lens you have chosen cannot be combined. Here is a longer answer:

A non-Canon lens on a Canon camera

This is a Nikon lens and unfortunately they are not constructed to work with Canon cameras. If the lens would have been a Sigma, Tamron och Tokina it would perhaps be different since they are available with a compatible Canon mount.