DENEBOLA (Beta Leonis). Great Leo,
which dominates northern spring skies,
contains three stars of note, bright Regulus,
second magnitude
Algeiba, which shares the "Sickle" with Regulus, and second
magnitude (2.14) Denebola. Denebola, Leo's Beta star, is the easternmost
of a prominent triangle of stars set to the east of Regulus. It
provides us with the Lion's tail, the name coming from the Arabic
phrase that means exactly that. Denebola is a white class A (A3) dwarf
(hydrogen-fusing) star
of temperature 8500 degrees Kelvin, and is similar to summer's
first magnitude Altair,
but at a distance of 36 light years it is
twice as far away and therefore dimmer to the eye. Like all the
brighter naked eye stars, Denebola is more luminous than the
Sun,
emitting 12 times the solar energy. It is one of a fairly rare
"Vega"
class of stars that is surrounded by a veil of infrared-
emitting dust. Since the planets of our Solar System were
apparently created from a circumstellar dusty cloud, such dust
implies the possibility that Denebola might have planets as well,
though there is no direct evidence for them. Denebola is also a
subtle variable star of the "
Delta Scuti" type. Such stars vary in
brightness by small amounts over periods of only hours. The star
shows no evidence for any kind of stellar companion.