From my past experience creating an "AllSkyCam" using a dedicated AstroImager (Meade DSI camera and 175-degree FOV lens), I found that the best (or, at least, most 'pleasing') results were obtained using 10-second exposures, and then post-processing to turm the sequence of images into a time-lapse video ( a frame rate of 10fps then giving 36 seconds of video per hour of time-lapse captured).
However, the biggest problem I think you will face (and I hope to stand corrected) is that there is no (easy) way to request 10-second exposures from the PiCam. You can ask for one exposure every ten seconds, but that is not the same!
There are webcams out there that can provide ten-second exposures - and some can be fairly easy to modify to be able to provide longer exposre times than that. But - you then need both the necessary drivers for the camera (typically connected over the USB interface), and you then need the high-level commands to control the image acquisition in the first place.
You are also going to have to think about the PiCam lens itself - it is not going to give you a 'wide' field of view, and it is not easy to remove and/or replace. You could try some of the smartphone lens 'adapters' that can be found on the likes of eBay - but I have no experience with these, and so cannot comment on final image quality.
I can't help you much further - I have barely been able to use my Pi since I bought it - specifically with astro-imaging in mind - because I have spent the whole summer carrying out long overdue repairs and modifications to the rolling roof of my observatory ahead of the dark skies of winter that lie ahead of us (bringing with them the promise of a very bright comet, expected to be easily visible throughout November/December).
Hopefully there are others who have tried this, and who will pass on their experiences and suggestions . . . . . .
Scatch-built BBC B in 82: blank PCB+scavenged plastics& PSU. Sinclair Calc & ZX81 kits in 74&82. PONG (AY-3-8500) in 77. 1st PC in 89: 386/25+387&10MbHDD. Have previewed pictures with my PiCam. I'll maybe save one next week (new to Linux)!