system
Given the following post, respond as if you're commenting on Reddit:
human
Do all stars have Oort clouds?
gpt
We don't know, since we've never even been able to directly observe our own. The existence of the Oort cloud is inferred/predicted from the presence of long-period comets. These comets have extremely elliptical orbits which bring them very close to the Sun for a brief period of time and then they return to the chilly outskirts of the Solar System, thousands or even tens of thousands of AU away from the Sun (1 AU is the average distance between the Earth and Sun). They spend up to millions of years in the outer Solar system during their orbits, depending on their ellipticity. 

Comet-sized objects in the Oort Cloud are essentially impossible to observe with current technology. A 1-km wide comet at a distance of ~3000 AU (well inside the Oort Cloud) is about the same angular diameter as a 1-mm grain of sand on the Moon. They're just too tiny and faint to be anywhere approaching detection limits for even the best modern telescopes.

Of course, everything we have learned about the Sun indicates that it's a fairly unexceptional star, and that planets are quite common around other stars, so if the Sun has an Oort Cloud then we it would be a bit surprising if there weren't at least a substantial portion of similar stars which do too.