The youngest type of Galaxy is
Linticular Galaxies
Spiral Galaxies
Elliptical Galaxies
Irregular Galaxies
Irregular Galaxies
The youngest type of galaxy is considered to be irregular galaxies.
The youngest type of galaxy is actually the irregular galaxy. To understand this, let's briefly define the other types of galaxies mentioned:
1. Lenticular Galaxies: These are intermediate galaxies that have a visible disk component like spiral galaxies but lack the distinctive spiral arms. They are considered intermediate because they have features of both spiral and elliptical galaxies.
2. Spiral Galaxies: They have a distinct spiral structure with arms that wrap around a central bulge. Spiral galaxies contain a mix of older and younger stars, but they are not the youngest type overall.
3. Elliptical Galaxies: These galaxies have an elliptical or oval shape without any spiral arms. Elliptical galaxies are often composed of older stars and have low levels of star formation, so they are generally considered older galaxies.
Now, let's focus on irregular galaxies. Irregular galaxies are characterized by their irregular shape and lack any particular structure like spirals or ellipses. They often contain a significant amount of gas and dust, and they exhibit ongoing star formation. Irregular galaxies are thought to be the youngest type of galaxies because they still have active star-forming regions, which means they are actively producing new stars.
To determine the youngest type of galaxy, we consider the presence of ongoing star formation as an indicator. By observing the amount of new stars being produced, astronomers classify irregular galaxies as the youngest type among the options you mentioned: lenticular, spiral, elliptical, and irregular galaxies.