This is the 1879th most frequent French word.
observer
To watch or notice something carefully.
Here, 'observer' is used to indicate the attentive watching of stars, emphasizing the activity of observing.
Je vais observer les étoiles ce soir.
I am going to observe the stars tonight.
Here, 'observer' means to comply with or follow rules.
Il est important d'observer les règles de la route.
It is important to observe traffic rules.
In this context, 'observer' is used to denote the act of watching carefully to analyze or learn about the subject.