The Heart of the Scorpion:
Antares, that is.
Also known as alpha Scorpius, the brightest (mag=0.9) red star in the summer sky, has a spectral class of M1 Ib. Compare this to the winter's M class star, the 0.7 magnitude Betelgeuse. Both stars are about 520 light years distant, and both are huge, at least as big as the orbit of Mars, although they are much less dense than our sun, thus have a much lower temperature, and redder color.
Betelgeuse was almost straight up for its portrait, whereas Antares barely rose 10° over South Mountain, so it's image is taken through a lot more atmosphere (not to mention competing with the streetlight right behind the cyprus tree just to the left of the star.) This is a 4 second exposure through an Amici prism behind a 32 mm Erfle ocular on the 6 inch f/4.9 Schwar dobsonian telescope.
Unfortunately Mars is similarly low in the sky this summer, and seeing will suffer as well. I wonder how the Chilean Andes are for an August vacation ..."
