Our Stellar Neighborhood

How do you pronounce “Vega” and “Canis Major”?

How do you pronounce “Vega”? “Canis Major”? In 1941 the American Astronomical Society formed a committee of Samuel G. Barton, George A. Davis Jr., and Daniel J. McHugh to consult with astronomers, educators, Arabic scholars, and planetarium lecturers and come up with a list of preferred pronunciations for common star names and constellations. Their final…

Were stars artistically depicted with diffraction spikes before the invention of the Newtonian reflector?

Were stars artistically depicted with diffraction spikes before the invention of the Newtonian reflector? If so, why? Stars were being drawn with points or spikes long before Isaac Newton announced his reflecting telescope in 1671. Just look at early works of art, flags, ancient coins, and the charts of the Pleiades and Praesepe star clusters…

The center of the stellar merry-go-round

What’s the distance to Polaris?

I have three astronomy programs on my computer that give three different distances for Polaris. I just obtained a fourth program, and it says the distance is unknown. What’s the problem? Those new to astronomy expect the distances of bright stars to be very accurately known, but many still aren’t. Different measuring techniques can yield…

Light curves by class

Why are there no green stars?

There are red stars, orange stars, yellow stars, and blue stars. Why no green stars? A star (or other hot object) emits light across the entire visible spectrum, but the wavelength at which it shines brightest depends on its temperature. Hotter stars emit proportionately more blue light than red; for cooler ones it's the other…