Because I am somewhat obsessive when curious, I dug through back issues and found the magazine issue I referenced. Chris Conrad is the name of the photographer, using 4x5 FP4+ or HP5+ in HC-110 and I quote:

"Pre-exposing the scene to build some shadow detail, he uses a combination of polariser and red filters - also adding split neutral density filters - to hold density down in the sky portion of the negative during his first exposure. After darkness falls, he opens the shutter again to catch the star and moon trails, often leaving it open for up to eight hours"

Something like this