Friday, January 14
The Circlet and the carbon star: A bright Moon floats inside the Circlet of Pisces, which includes the red carbon star 19 Piscium, visible as the red point below the Moon.
The Moon reaches apogee, the farthest point from Earth in its orbit, at 4:26 A.M. EST. At that time, our satellite will be 252,155 miles (405,804 km) away.
With the bright Moon in Taurus tonight, let’s cast our gaze across the sky to Pisces to discover one of the sky’s reddest rubies. 19 Piscium, also called TX Piscium, is a deep red carbon star. This means it’s in the later stages of its life and has puffed up into a cool red giant. That alone will make a star appear redder, but carbon stars go one step further: These stars have abundant carbon in their atmosphere, which readily scatters blue and green wavelengths of light so only the red can shine through. Thus, carbon stars appear particularly red.
To find 19 Psc, step outside early in the evening, before Pisces has...