What is the difference between a barred spiral and lenticular galaxy?

A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter. There are many different types of galaxies, but two of the most commonly studied are barred spiral galaxies and lenticular galaxies.

Barred spiral galaxies have a central bar-shaped structure surrounded by spiral arms. The bar is thought to be a temporary structure that helps to transport gas and stars toward the center of the galaxy. Lenticular galaxies, on the other hand, are disk-shaped and have no spiral structure. They are often described as an intermediate between spiral and elliptical galaxies.

Another key difference between barred spiral and lenticular galaxies is their star-forming activity. Barred spiral galaxies are typically more active in terms of star formation, while lenticular galaxies have much lower rates of star formation. This is thought to be due to the fact that lenticular galaxies have used up most of their gas and dust, which are the raw materials for forming new stars.