November 27 – December 10, 2017
Mount Washington — Our Sun sets in the southwest at around 4:20 in the afternoon. When twilight gathers, golden Capella, the fourth brightest star in northern skies, commands our attention above the northeastern horizon. Capella, from the Latin for “she-goat,” is the brightest star in the constellation Auriga the Charioteer. At nightfall four lesser stars appear, shaping a pentagon that represents the chariot and charioteer. On the upper right of the pattern, a cluster of dimmer stars, sometimes called “the kids,” are rendered in artwork as a kid or many kid goats held under the arm of the charioteer.
Aldebaran, the ninth brightest star in our skies, appears to the right of Capella, east, closer to the horizon at nightfall. Known as the eye of Taurus the Bull, Aldebaran is distinctly orange. Taurus’ lesser stars shape the triangular head of the Bull. Capella and Aldebaran are visible all night even in urban, light-polluted skies. But even in dark sky locations, look for their constellation of lesser stars before Dec. 1, when the light of the waxing gibbous moon shines nearby.
The largest full moon of 2017, a Perigean Full Moon, popularly known as a supermoon, occurs on Sunday the 3rd of December. The precise moment of full moon is 10:48 a.m. on the 3rd. Doing the math tells us that moonset on the morning of 3rd, 6:40 a.m., will be slightly closer to full than moonrise at 4:53 p.m. Perigee, when the moon is closest to Earth, occurs at 3:46 a.m. on the 4th, several hours closer to moonrise on the evening of the 3rd. Confused? Be there for both moonset in the west Sunday morning and moonrise in the east that same night. There’s a bonus on Sunday morning: Aldebaran follows close to the top left of the orb of the year’s closest full moon, the Long Night Moon.
Astronomical twilight, the measure of darkness at which night begins, is within minutes of 6 o’clock through December. The earliest sunsets of the year, 4:21 p.m., are from Wednesday the 6th through Tuesday the 12th. These are sunsets farthest south of west for the year.
If you are adding outdoor lighting for the holidays, please connect all lights to a timer – or be diligent about extinguishing them before bedtime – so that the eyes of nighttime and early-morning stargazers may stay acclimated to the dark. Consider that when each household, business and public venue in a community minimizes lighting the outdoors, collectively we will decrease light pollution and its ill affects on all life.