Yes. Some spiral galaxies do contain at least 1 trillion stars.
(Atoms) Stars, Dust.
Spiral arms are parts of galaxies - both the galaxies and their spiral arms are huge, by our everyday standards. Spiral arms basically contain most of what the galaxies contain - including stars, dust, gas.
While spiral galaxies are bright, elliptical galaxies are dim. Spiral galaxies are hotbeds of star formation, but elliptical galaxies aren't nearly as prolific because they contain less gas and dust, which means fewer new (and brighter) stars are born
milky way is a spiral galaxy spiral galaxies have younger stars in the arm and older stars in the middle
There are generally three types of galaxies: spiral galaxies, elliptical galaxies, and irregular galaxies. Spiral galaxies like the Milky Way have a disk shape with arms of stars spiraling out from a central core. Elliptical galaxies are shaped like ellipses and contain mostly older stars. Irregular galaxies have a less defined shape and tend to have a mix of young and old stars.
Yes. The Andromeda Galaxy, the nearest spiral galaxy to our own, may have as many as 1 trillion stars.
Spherical galaxies are characterized by their round shape and lack of distinct spiral arms. They contain mostly older stars and have a dense central bulge. These galaxies are often found in clusters and have a more uniform distribution of stars compared to spiral galaxies.
The brightness of normal galaxies is mainly due to stars; quasars are believed to get most of their energy output from the black hole at their center.
Spiral galaxies are named for the (usually two armed) spiral structures that extend from the centre into the disk.The spiral arms are sites of ongoing star formation and are brighter than the surrounding disk because of the young, hot stars.See related link for a pictorial representation.
Population I (High metal content) stars are generally found in the arms of spiral galaxies, whereas population II (Medium metal content) are generally found towards the centre of the galaxies.
A spiral galaxy is just a type of galaxy but I can tell you that the stars in the middle are the oldest and the ones on the outside are the youngest.
Both contain large numbers of stars, plus dust, gas, and magnetic fields.