If a rock the size of Oumuamua were to crash into the sun — assume central collision — would it materially affect the sun’s behaviour? Would unaided humans (rather than sun-tastic special telescopes) notice a change in the sun’s brightness or colour or something?
What if the rock were the mass of Pluto? The Moon? The Earth? How big a rock can smite the sun and unaided humans not notice?
Edit: this is not about long-term effects of a merger. This is about the on-the-day or maybe in-the-month effects. How large would a rock need to be for its collision with the sun to have an effect?