Well I tried to land my ASP on the structures, with the right ship, It might work....
View attachment 113362
Just another theory

You could try and see which configuration lets you land !
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I think you might want to add some explanations to your numbers, that would help me (at least) understand what you are going about. I Also looked at your pictures and I see alignments but what I don't really see is star patterns. All I know is that a few named stars are in the area, Canis majoris and Betelgeuse. In a way maybe they lived in betelgeuse and when It went into its super giant stage they had to flee. Or they live in a star close by and decided to move out of the future Nova shockwave and something went horribly wrong with their plans.
What bugs me most about the site, is its usage. It looks small, so to me it's an outpost and as it looks fortified, I would say military outpost. If it is one, then It could be the edge of their bubble. Now how to determine the direction to take and the type of stars that they might prefer, that is pure speculation.
If the site is a star map, then for a starfaring species, it would be strange to build a site as a Stone Henge. I have trouble buying this theory as they have computers for that. If its a site for remembering who they where, why so small? and why in one place. If you want to be found one day you build lots of structures (lots of duplicate data), and lots features on the ground so you will be found. You also choose a stable star, like a K start or red dwarf. They live so long that you are sure someone will one day find you.
They don't do that by choosing a F class star that will go super nova in less than 10 billions years and wipe out your site.
Last but not least, a catastrophic event civilisation crash in less than a century with instant loss of FTL, then maybe that could explain the loneliness of the place.