What are the three broad categories used to group galaxies based on visual appearance?
Answer
Spirals, ellipticals, and irregulars
Galaxies are generally grouped into three main categories: spirals, ellipticals, and irregulars, although many sub-types and transitions exist between them.
Related Questions
What are the three broad categories used to group galaxies based on visual appearance?What dynamic characteristic sets elliptical galaxies apart from spiral galaxies like the Milky Way?What feature do elliptical galaxies characteristically lack compared to flatter disk galaxies?In the Hubble sequence designation for ellipticals (E0 to E7), what does the numerical value quantify?Which elliptical classification is reserved for galaxies that appear almost perfectly circular when observed?What is the mathematical relationship used to calculate the numerical designation for an elliptical galaxy based on major axis ($a$) and minor axis ($b$)?What is required internally for a galaxy to be considered truly spherical in terms of stellar motion?What observationally induced effect can cause a highly elongated galaxy to be erroneously classified as E0?What process is commonly responsible for creating the random stellar motions characteristic of elliptical galaxies?What is the general consensus among astronomers regarding the E0 designation and perfect sphericity?What happens to the organized rotational energy of spiral galaxies during a major merger that forms an elliptical?