The spec sheet on Ilford's Delta 400 shows the red response extending to almost 700nm, which should be good for HA astrophotography. But after my experience with SFX-200 (which really wants very bright light) I half expected this film to be red-dead for AP. A couple of website articles mentioned that the grain size is virually the same at 800 ISO as it is at 400.
So I decided to give the film a try and develop it at 800 and see just what I got for results.
Using my Pentax MX with a 50mm lens at f/2.8 I shot one frame unfiltered with a 10 minute exposure and another frame with a Lumicon HA filter at f/2.8 for 30 minutes.
The snippet of film (I'm cheap) was developed in HC-110 dilution B for 10 minutes.
The polar alignment was very rough (Polaris is in the circle, close enough ) hence the field rotation.
Here is the result of the filtered shot.

I think this justifies some more testing. Hypered tech pan it isn't, but this film is straight out of the box. There may be some additional "nebulae" due to incomplete washing of the film. At the very least it should make a good "introductory" film for those just starting out.
 
 
 
 

And just to round things out here is the 10 minute unfiltered shot of he same region.