Cepheid variables are massive, pulsating stars, valued by astronomers for the precise link between their brightness and steady pulsation. Let’s look at the history of Cepheid variables and how recent discoveries about these stars shatter established theories of stellar evolution. Cepheid variable stars have been known since the 18th Read more…
What is light? Here’s an easy introduction to the electromagnetic spectrum all the way from radio waves to gamma rays. Before the modern era of technological astronomy, to know anything about the Universe beyond our planet we relied on light. We had to see planets, stars, and so on, to Read more…
Imagine that once the Sun sets, rather than a dark sky sprinkled with a few thousand dim stars, we had a sky blazing with ten thousand or so stars blazing brighter than Venus. How different would astronomy, mythology, everyday life be? Planets orbiting stars in the NGC 3603 Young Cluster Read more…
Here’s how rainbows are made. Some 13.7 billion years ago, a mere millionth of a second after the Big Bang, the first hydrogen and helium nuclei condensed out of a hot, dense soup of quarks and gluons. It took another 380 000 years or so for conditions in the ancient Read more…
At first glance Gliese 710 is not a very distinguished star. A K7 class orange dwarf a bit more than half as massive as the Sun, it currently lies about 63 light years from us in the constellation Serpens. It is moving fast though and that is why one reason Read more…
Around this time of year, go outside after 9pm on a clear night and look at the sky. Even if it is not quite dark a bright star will be visible in the south. This is Vega, the third brightest star in our sky (only Sirius and Arcturus are brighter). Read more…