400,000,000,000.
We have no idea. Since the Triangulum galaxy is quite distant, we certainly cannot see any individual planets; we cannot even see individual STARS at that distance unless they are quite bright. We can GUESS; for the nearby stars that we have studied using the Kepler Space Telescope, we seem to be averaging about one planet per star. The Triangulum Galaxy, M33, is somewhat smaller than the Milky Way or the Andromeda Galaxy, and Wikipedia estimates it at perhaps 40 billion stars, and estimate that is probably quite low. (We are discovering that there are far more of the small dim stars around than we had expected.) So a reasonable first approximation for the number of planets present there would probably be somewhere on the order of 100 billion. But that's a GUESS.
A star - especially as a galaxy is formed of billions of stars.
Yes. The Star Wars galaxy does have 400 billion stars.
There are stars in any galaxy. That's, to a great extent, what a "galaxy" is all about: a huge collection of stars.
In order of distance from EarthNeptuneBarnard's StarAndromedaTriangulum
Yes. A galaxy contains many stars.
No. A Galaxy contains billions of stars whereas a binary star contains only two stars.
A star doesn't become a galaxy. A galaxy is a colection of (among other things) millions, but usually billions, of stars.
All stars we currently know of are part of a galaxy. Stars are born within galaxies from clouds of gas and dust. If a star were to exist without belonging to a galaxy, it would likely be a result of very rare and extreme circumstances, such as being ejected from its parent galaxy due to a collision or interaction with another galaxy.
20,000,000 dots (5,000,000 in known galaxy) represent the number of sentient species (excluding humans) in the Star Wars galaxy (an alternate version of the Triangulum galaxy, a spiral galaxy 3 million light-years from Earth that is 100,000-120,000 light-years in diameter and contains 400 billion stars (100 billion in known galaxy), 180 billion star systems (~50 billion in known galaxy), etc.). They come in all shapes, sizes, colors, unusual features, etc.
There are 400 billion stars in our galaxy - we can't name them all.
The sun is a star but the sun is a star but it is the only one in our galaxy, the milky way.