yes
Smaller galaxies do. Larger galaxies contain billions or even trillions of stars.
None. Galaxies on the other hand do contain planets
Galaxies can be classified into three main sizes: dwarf galaxies, which are small and contain less than a few billion stars; Milky Way-sized galaxies, which are intermediate in size and contain a few hundred billion stars; and giant galaxies, which are massive and can contain trillions of stars.
Spiral and irregular galaxies.
Yes. Some spiral galaxies do contain at least 1 trillion stars.
Yes. Some dwarf galaxies contain at least 1 billion stars.
Yes, most galaxies contain billions of stars. For instance, our Milky Way galaxy is estimated to have around 100 to 400 billion stars. However, there are smaller galaxies, known as dwarf galaxies, that may contain as few as a few million stars. Despite this variation, the majority of galaxies are star-rich and typically hold vast numbers of stars.
quasars.
quasars.
Galxies were once thought to be nebulaes
quasars.
Yes. Some giant elliptical galaxies contain tens of trillions of stars.