 Now let's take a look at a few stars, too far away for Hipparchus, but well within the range of Gaia. Betelgeuse is a very rich, reddish, cool, supergiant star. It is also one of the largest and most luminous stars known. If it were at the center of the solar system, its surface would extend past the orbit of Jupiter. CHCYG is a symbiotic star system in which a white dwarf feeds from the solar wind of a companion red giant star. Rigel is the sixth brightest star in the sky. Since 1943, this star has served as one of the stable anchor points by which other stars are classified.