Denebola is Beta Leonis, apparent magnitude 2.11, at roughly 36 light years. It is a white main-sequence star, type A3, rotating rapidly and slightly variable, and it is young enough to retain a disc of debris detectable in the infrared, a system perhaps still forming or clearing planets. The Arabic name, from dhanab al-asad, means simply the tail of the lion, its position in the figure. It marks the eastern end of Leo, opposite the bright Regulus at the heart.
The debris disc around Denebola, detected through excess infrared radiation the dust re-emits after absorbing the star's light, marks it as a young system still possibly shedding material left over from planet formation; at only thirty-six light years it is close enough that the disc has been a useful nearby laboratory for studying how such systems evolve. Denebola's youth and rapid rotation together make it a star still settling into stable adulthood by stellar standards, a useful nearby example for astronomers studying how debris discs and planetary systems evolve around A-type stars generally. Denebola's proximity, among the nearer bright stars in this entire set of tables, makes its debris disc an unusually well-studied nearby example of the type.
Sources AstronomyAndrew Fraknoi, David Morrison, and Sidney C. Wolff (OpenStax) with Almagest (Mathematike Syntaxis)Claudius Ptolemy