Galaxies can be grouped by the age of the stars they tend to contain, with Response area galaxies having the youngest stars and Response area galaxies having the oldest stars.

Answer 1

Galaxies can indeed be grouped based on the age of the stars they contain. Generally, there are two main categories:

1. Blue Galaxies: These are typically spiral galaxies that contain young, hot stars. The presence of young stars gives these galaxies a blue color. Blue galaxies tend to have active star formation and are often found in areas with abundant gas and dust.

2. Red Galaxies: These are generally elliptical galaxies that contain older, cooler stars. They appear red due to the lack of young star formation and the predominance of older stars. Red galaxies usually have exhausted their gas reserves for star formation and are often found in more densely populated regions of the universe.

So, in summary:

• Galaxies with the youngest stars: Blue galaxies
• Galaxies with the oldest stars: Red galaxies

These classifications can help astronomers understand the evolution and life cycle of galaxies in the universe.