September 2002

By Steve Stefanik

This September the planet Venus is the "opening act" for the annual full Harvest Moon, which occurs on the night of the 21^st.

Venus is the only visible planet in the evening sky. You shouldn’t miss it or confuse it with anything else except maybe an airplane with its headlights on coming in for a landing low in the southwestern sky. At a brilliant –4.6 magnitude, it is more than 5 times brighter than Vega the brightest star in the summertime sky. But, you’ve got to be quick about it because it sets within an hour of the sun.

The Harvest Moon is so named because during this time of year the moon rises at dusk several nights in a row around the full moon, which affords enough light and time for farmers to get the crop harvested before the first killing frost may occur which is possible seeing that the Fall Equinox occurs just a few days later on the 23^rd at 12:55 a.m. EDT.

If you have binoculars or even a small telescope you may also be able to locate two more planets, Neptune and Uranus, among the stars of the constellation Capricorn, which is low in the southern sky. Uranus is the easier of the pair to spot because it is bigger and brighter than Neptune because it is closer to earth. Look for this blue-green +5.8 magnitude orb on the eastern edge of the constellation. Neptune is considerably more difficult to locate at +7.8 magnitude because it is farther and dimmer than Uranus. You will find it on the opposite side of Capricorn on its western border.

If you are still up at midnight, you can catch an early glimpse of the "ringed" planet, Saturn, rising above the eastern horizon. It is between the western edge of the constellation Gemini "the twins" and the eastern edge of the constellation Taurus "the bull". Don’t mistake it for the bright first magnitude red-orange star Aldebaran, which is about the same color and brightness as Saturn in nearby Taurus. Through binoculars or a telescope you will see the unmistakable elliptical shape of its rings.

The planet Jupiter rises about 3 hours later in the constellation Cancer "the crab". There’s no mistaking this –1.9 magnitude gas giant even though –1.4 magnitude Sirius, the brightest star in the sky, lurks in nearby Canis Major, "the big dog", in the southeast. Upon inspection with binoculars or a telescope you will see its accompanying 4 Galilean moons to be sure. During the first half of the month it lies within a degree of M44, the Beehive Cluster of stars.

The planets Mars and Mercury are too low on the eastern and western horizons respectively and will be obscured by the sun’s glare this month.

While you are out and about on these late summer and early fall evenings you might notice that the stars of "the Summer Triangle", Vega in the constellation Lyra "the harp", Altaire in the constellation Aquilla "the eagle", and Deneb in the constellation Cygnus "the swan" are directly overhead foreboding Fall is not far off and Winter is on its way.