This is the 3514th most frequent Russian word.
расстоянии
"Distance."
In this sentence, 'расстоянии' ('at a distance') is used to denote the physical separation between observer and stars in spatial terms.
Мы наблюдали за звездами на расстоянии миллионов световых лет.
We observed stars at a distance of millions of light-years away.
Here, 'расстоянии' is used to indicate a measurable separation that is conveniently contextualized by a familiar measure (arm's length).
На расстоянии вытянутой руки лежала книга.
The book lay at arm's length.
In this usage, 'расстоянии' metaphorically describes emotional or relational separation being equated to a physical distance.