Is the narrative authentic that says that Allah sent a star on the house of Maula Ali AS as an indication of Allah’s Will that Fatima AS must only marry him?
It is mentioned in La'ali al-Akhbar (vol 3, p 413) and attributed to Imam al-Baqir (A) that the angel Jibra'il told the Prophet (S) that the planet Venus (the evening star) would descend on Friday night on the house of the person whom Fatima (A) should marry. The people waited to see who it was, and it was the house of Ali (A).
This narration is provided as part of the explanation of the origins of the tasbih of Fatima al-Zahra (A).
I am personally not aware of any chain of narration for this and therefore, without a chain of narration, it would not be classified as authentic.
Allah knows best.