NavList:

"Also in the 1950s, a special stabilized periscope, the Type 11 'star-tracker,' was developed specifically for ballistic missile submarines to facilitate the more accurate navigation needed for missile launches. It was designed to take azimuth sightings of stars to update the planned Ships Inertial Navigation System (SINS), and it was the first periscope developed specifically for the nuclear-powered age."

https://issuu.com/julianne.m.johnson/docs/usw_fall_2004/s/10622073

I vaguely remember a discussion on a forum about this (maybe Subsim.com). I think a picture of a surfaced submarine had been posted with many of its periscopic instruments extended. Some members were speculating about what they were, and one member identified one of the instruments as a type of star tracker. This, of course, piqued my interest. I can't find that particular discussion, but I did find this: https://www.subsim.com/radioroom//showthread.php?t=218130

Apparently, the only link I did save was to the exact same article Paul linked earlier.

Cheers!

Sean C.