galaxies are best classified by
select all that apply.
shape
color
stars
age
shape
stars
age
Galaxies are best classified by shape, stars, and age.
Galaxies can be classified by several different factors. Let's go through each of the options you've provided:
1. Shape: This is one of the main ways that astronomers classify galaxies. There are generally three main shapes of galaxies: spiral, elliptical, and irregular. Spiral galaxies have a distinct center with spiral arms extending outwards, while elliptical galaxies are more rounded and lack defined spiral arms. Irregular galaxies have irregular shapes with no clear structure.
2. Color: While color can be an indicator of the content and age of stars within a galaxy, it is not typically used as a primary classification method for galaxies. However, by observing the colors of galaxies, astronomers can gain insights into their stellar populations, star formation rates, and chemical composition.
3. Stars: The presence and characteristics of stars in a galaxy can provide valuable information for classification. For example, the types of stars present, their sizes, and their distribution throughout the galaxy can help categorize galaxies.
4. Age: The age of a galaxy is another important factor for classification. Astronomers can estimate the age of galaxies by looking at their star formation rates, the presence of young or old stars, and the evolution of their stellar populations over time.
In summary, both shape and stars are important factors in classifying galaxies, while color and age can also provide additional insights but are not the main criteria for classification. Therefore, the options "shape" and "stars" should be selected as the best classifications for galaxies.