We looked at two stars that are candidates
for supernova explosions in the near future, relative to the time it takes
a star to move through its life cycle. The first star we observed is Betelgeuse.
It lies in the constellation of Orion at his upper shoulder. Observing
with 10x50 binoculars on April 13th at 9:30 P.M. we noticed its reddish
color. Through a 10” Newtonian reflector less color was visible.
The low surface temperature of Betelgeuse, approx. 3000 Kelvin (Menzel
& Pasachoff, 434), causes its peak radiation to be tilted to the red
end of the scale. On the night of April the thirteenth at nine-thirty P.M.
Orion was visible looking due West, close to the horizon. Its distance
from the Earth is 310 light years (Menzel & Pasachoff, 434). Betelgeuse
is one of the brighter stars in the sky with a absolute magnitude of -5.6.
Its spectral class is that of a M2 luminosity class I (Menzel & Pasachoff,
434). The H-R diagram shows that Betelgeuse is a cool star, but very luminous
due to its large radius. It has a radius close to a thousand times that
of our sun (H-R diagram workshop, 5-18-99). Betelgeuse is a good
candidate for a supernova
because it late in its life, and has a large radius.
Current models show that Betelgeuse has already built up a layered core
structure due to its series of contractions and expansions. while raising
its core temperature high enough to burn heavier and heavier elements in
its core.
Antares is the second star we observed.
It was visible on April twentieth at two A.M., just above the Southern
horizon. Antares is also a massive supergiant that may be nearing the end
of its life. We observed with 10x50 binoculars and noted its reddish tint.
It is about 2.5 times dimmer than Betelgeuse with an absolute magnitude
of -4.7 (Menzel & Pasachoff, 434). Its spectral class/luminosity class
is a M1 II (Menzel & Pasachoff, 434). Antares is located near the center
of the constellation of Scorpio.
