Isaac covered the specifics but, generally speaking, stars are never more than point sources of light to terrestrial observers. It is one of the more disappointing things about amateur astronomy: Even with really powerful telescopes (like, 250+ mm aperture beasts that can run as much as a new car) one can easily separate a lot of double/triple/etc. stars, but stars are STILL just dots. Sirius at 450X on my old 114 mm aperture reflector is a REALLY cool little kaleidoscope (I still have no idea HOW it can change through so many colors so quickly,) but remains a dot, not a disc. I can get choice views of the Moon and planets with that, so that is how I usually go; I just have to remember not to look at the full moon with low magnification so I do not go blind.

Most truly breathtaking stuff is deep sky (i.e. extragalactic) and thus faint, requiring a fairly large aperture, and/or tracking motor and camera (to overcome faintness with time lapse photography). Ideally, both are best, but that 114 mm of mine is about the bare minimum for deep sky (part of why I got it) and for really nice visual or photographic deep sky images 200 mm is where one should start (obtainable at good quality for $1000-2000 new, far less if you want to take your chances on EBay.)

Unfortunately, these days it is harder and harder to find those 200 mm (or 8 inch, as they are usually sold) scopes without all the fancy star charts and computerized crap included. That stuff is undeniably convenient and simple, but roughly doubles the price of a scope, mount and motor (which is all I want; I can read a map, thanks. ) If someone has never (or rarely) used a telescope I concede it is nice to just hit a few buttons to calibrate it and then tell it you want to look at the Crab Nebula, Saturn or the space station, but most people like that will not spend $1000+ on a telescope in the first place.

Having said all that, it was only after some cursory follow up research once I saw this article that I realized what a funky little star Betelgeuse is. Apparently it was expelled from its local cluster (probably) due to an EARLIER supernova, and is now classed as a "runaway star" shooting through the cosmos alone at a high rate of speed. Plus it is a short period variable (which actually is not that uncommon for red giants,) so it can vary in brightness by an entire magnitude within just a few years. Apparently there is even some debate over just how far away it is (no doubt its variable magnitude complicates measurement;) Wikipedia lists its distance as 643±146 light years, which is a pretty big margin of error.