Variable Stars and the Stories They Tell: Exoplanets and the Search for Extraterrestrial Life
©February 2018 by Dale Alan Bryant
(In memory of M.I.T. astrophysicist Dr. Philip Morrison - who started all this...)
Though the figures are tough to keep up with - they are changing, almost daily - the Kepler Space Telescope (KST) has discovered, to date, over 4,500 exoplanet candidates, ~3,400+ of which have been confirmed.
The term "sunspot" appears in the news, often in connection with stories on aurorae, electrical outages, and problems with orbiting satellites. But often these stories don't really explain what sunspots are and why they're of interest to us on Earth. So what are sunspots?
Distances in the universe are so vast that we do not have a simple way of measuring them. For distances within the solar system we can measure them directly, using radar for example, and some very straightforward trigonometry. But radar is hard to use when it takes light minutes or hours to cross the solar system; and the nearest star is four light years awa
Variable stars highlight an important fact about the heavens above us: the universe is always changing. The universe is very large, stars and galaxies are very far away, and many changes occur on timescales far longer than we can see. Most things in the sky -- stars, nebulae, and galaxies -- don't appear to change at all during the course of a human lifetime.
