Which characteristics are considered most typical of an old galaxy in decline?

Question

A. Low gas content, little star formation
B. Shrinking size, high dust content
C. Spiral, abundant planets present
D. Very bright, relatively small

Answer 1

The most typical characteristics of an old galaxy in decline are:

A. Low gas content, little star formation

Old galaxies tend to have consumed much of their gas in star formation, leading to a decreased rate of new stars being formed. As a result, they often exhibit low gas content and little ongoing star formation.