The concept of a solitary star without any 'nearby' neighbors features in Iain Banks' Against A Dark Background: https://www.goodreads.com/book/show/422452.Against_a_Dark_Ba...
Had this been known at the time, she could have simply dispensed with the light from the nearest galaxy altogether.
Similarly, the planet Krikkit, as described in Douglas Adams' Hitchhiker's Guide "Trilogy", would not necessarily be all that unique or unusual.
I'm not sure if there is already a sub-reddit for story ids.