This is the 14724th most frequent Turkish word.
rastlanan
"Rastlanan" means "encountered" or "found."
Here, 'rastlanan' is used as an adjective derived from the verb 'rastlamak' (to encounter), modifying 'yıldızlar' (stars) to signify 'encountered stars'.
Gökyüzünde rastlanan yıldızların bu gece parlak olduğu fark edildi.
It was noticed that the stars encountered in the sky were bright tonight.
In this sentence, 'rastlanan' again serves as an adjective describing 'harabe' (ruins), denoting 'ruins that were encountered'.
Ormanda rastlanan harabe yıllardır kimse tarafından ziyaret edilmemişti.
The ruins encountered in the forest had not been visited by anyone for years.
Here, 'rastlanan' is used to characterize 'eski dost' (old friend), indicating 'the old friend whom one encountered'.