This is the 6979th most frequent Russian word.
артеменкoв
"Артеменков" is a Russian surname and does not have a standalone definition in English.
The word 'Артеменков' is used here as a proper noun, presumably a last name of a character observing stars.
Дети играли во дворе, а Артеменков с друзьями смотрел на звезды.
The children were playing in the yard, while Artemenkov and his friends were stargazing.
Here, 'Артеменковым' is instrumental case showing that Artemenkov, as an individual, performed the action of building the house.
Дом, построенный Артеменковым, стал известным в городе.
The house built by Artemenkov became famous in the city.
In this sentence, 'Артеменкова' is a feminine version of the surname, indicating possession or a subject in a feminine gender.