First one is especially cool! Nice exposure of trees.
The best star trail shots always include some foreground for reference, even if it's something you must illuminate with flash or paint with flashlight.
OK, Fixed the link to the Elph300 sample above. Reason I included it is because I have been unable to turn off DFS with the latest release, albeit Alpha, CHDK. The camera has a wonderful 24mm wide lens for this kind of work but requires a program called StarTracer to fill in all the gaps created by DFS.
Until I can get DFS off, or find another 24mm lens camera where DFS works, StarTracer is the answer.
TIP - You can also use StarTracer to extend the trails if your session was cut short with clouds or crappy battery.