Surah At-Tariq 86:3

ٱلنَّجْمُ ٱلثَّاقِبُ

It is the piercing star

Translation: Saheeh International

Tafsir

The piercing the brilliant because of its piercing the darkness with its light star! meaning the constellation Pleiades; or it refers to all stars the response to the oath follows

Excerpt from Tafsir al-Jalalayn, commentary on 86:3, via Quran.com. The reader has the full commentary and 9 more tafsirs.