<P> The carbon star CW Leo (IRC + 10216) is the brightest star in the night sky at the infrared N - band (10 μm wavelength). </P> <P> The star SDSS J102915 + 172927 (Caffau's star) is a population II star in the galactic halo seen in Leo . It is about 13 billion years old, making it one of the oldest stars in the Galaxy . It has the lowest metallicity of any known star . </P> <P> Modern astronomers, including Tycho Brahe in 1602, excised a group of stars that once made up the "tuft" of the lion's tail and used them to form the new constellation Coma Berenices (Berenice's hair), although there was precedent for that designation among the ancient Greeks and Romans . </P> <P> Leo contains many bright galaxies; Messier 65, Messier 66, Messier 95, Messier 96, Messier 105, and NGC 3628 are the most famous, the first two being part of the Leo Triplet . </P>

How many stars make up the leo constellation