KORNEPHOROS (Beta Herculis). Some
constellations, exemplified by Orion, stand out brilliantly among their neighbors.
But brightness does not necessarily mean unimportance, as testified
by Hercules, one of the oldest and
best known constellations in the sky even though its brightest
star, Kornephoros, is third magnitude (albeit at the bright end of
third, 2.77). The constellation that honors the Greek hero was
originally known as "the Kneeler," a man of ancient though unknown
significance. Though Kornephoros is the brightest star of the
constellation, it lost the Alpha designation to Rasalgethi as that star is in the
Kneeler's head (the name's meaning). As a result, Kornephoros
received the consolation prize of Beta. Instead of referring to
the Kneeler, Kornephoros, which from Greek means the "club-bearer,"
refers to Hercules himself through one of his mighty weapons. Like
Alphecca in Corona Borealis and Graffias in Scorpius, Kornephoros has two proper names, the other
"Rutilicus," a corruption of a Latin word meaning "armpit" and
referring to the man of the constellation. In reality Kornephoros
is a yellow, relatively cool (4900 Kelvin) class G (G7)
giant 148
light years away with a luminosity
175 times that of the
Sun. From these data we find a radius nearly
20 times solar as befits a giant of its stature. The star is
similar to the main component of Capella, though a bit warmer, and 60
percent brighter. From its temperature and luminosity it is also,
at about three solar masses, somewhat more massive. As a giant the
star is evolving rapidly, and is now most likely quietly fusing the
helium in its core into carbon and oxygen, having begun life (when
it was fusing hydrogen) as a hot "main sequence" class B star
somewhat like Zubeneschamali. In
fact the star is just what Zubeneschamali will look like in 200 or
so million years. Little else distinguishes Kornephoros. It is a
very normal star for its state of age. It is a significant source
of X-rays that reveal some magnetic activity, and has a nitrogen
abundance enhanced relative to carbon (also not unusual). Like so
many other stars it also has a companion, but one unseen and known
only through the gravitational effect it has on the visible star
(causing it to move back and forth along the line of sight). The
companion, about which almost nothing is known, probably has a mass
a bit higher than that of the Sun. Kornephoros is not big enough
to explode, and will finally die as a fairly massive
white dwarf
rather like the companion to Sirius.