july 2011 - Astronomical Society of Southern Africa

canopus july 2011
not occurring on time, but were sometimes too early or too late. This led them to
hypothesize the presence of two giant planets whose gravitational effect would cause
the stars' orbit to wobble and consequently slightly alter the measured time between
eclipses. The astronomers were also able to infer that the masses of the two planets must
be at least 6 and 8 times that of Jupiter and take 16 and 5 years respectively to orbit the
two stars. The system is too far away from us to be imaged directly.
Artist impression (Credit: http://www.saao.ac.za/typo3temp/pics/9f2c961304.jpg)
This binary star system (known as UZ For) would be an extremely inhospitable
environment. Due to their close proximity, the gravity of the white dwarf is constantly
“stealing” material from the surface of the red dwarf in a continuous stream. This
stream crashes onto the white dwarf where it gets super-heated to millions of
degrees and subsequently floods the entire planetary system with enormous
amounts of deadly X-rays.
This discovery was made possible by new SAAO and Southern African Large
Telescope (SALT) observations combined with archival data spanning 27 years,
gathered from multiple observatories and satellites.
A Big Surprise from the Edge of the Solar System
Submitted by Lerika Cross
June 9, 2011: NASA's Voyager probes are truly going where no one has gone before.
Gliding silently toward the stars, 9 billion miles from Earth, they are beaming back news
from the most distant, unexplored reaches of the solar system.
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