any star having a relatively large radius for its mass and temperature; because the radiating area is correspondingly large, the brightness of such stars is high. Subclasses of giants are supergiants, with even larger radii and brightness for their masses and temperatures (see supergiant star); red giants, which have low temperatures but are of great brightness; and subgiants, which have slightly reduced radii and brightness.
Some giants have luminosities hundreds of thousands of times that of the Sun. Their position in the Hertzsprung-Russell diagram is above the main sequence, in which the majority of stars, called dwarf stars in contrast, fall. Masses of giants and supergiants may be 10 to 30 times that of the Sun, but their volumes are often 1,000,000 to 10,000,000 times greater. Thus, they are low-density “diffuse” stars.
Link to this article and share the full text with the readers of your Web site or blog-post.
If you think a reference to this article on "giant star" will enhance your Web site,
blog-post, or any other web-content, then feel free to link to this article,
and your readers will gain full access to the full article, even if they do not subscribe to our service.
You may want to use the HTML code fragment provided below.
We welcome your comments. Any revisions or updates suggested for this article will be reviewed by our editorial staff. Contact us here.
Regular users of Britannica may notice that this comments feature is less robust than in the past. This is only temporary, while we make the transition to a dramatically new and richer site. The functionality of the system will be restored soon.