We have only recently been able to detect them at scale, so we should not confuse first ones detected with first ones to arrive in the solar system. It’s just as likely they are the tail end of a debris cloud, but our detection tech wasn’t up to spotting all the previous ones.

I find this to be an interesting thought.

Earth is currently traveling through the Local Interstellar Cloud, a region of gas, dust, and plasma, and a recent study suggests that the solar system may have recently passed through a dense cloud of supernova debris. Evidence for this supernova event includes the presence of the radioactive isotope iron-60.

This one is anything but small.