Non-Profit Internet Source for News, Events, History, & Culture of Northern Frederick & Carroll County Md./Southern Adams County Pa.

 

The Night Sky of September

Dr. Wayne Wooten
Professor of Astronomy 

For September 2014, the Moon will be first quarter on September 2nd, and sits about 8 degrees north of red Antares in Scorpius. It passed just 4 degrees north of similarly bright and red Mars on the previous evening. Mars will overtake Antares at month’s end of a spectacular red double star, only 3 degrees apart on September 28th. The Full Moon, the Harvest Moon, is on September 9th. The Moon is last quarter on September 16th. It passes five degrees south of Jupiter in the dawn sky on September 20th.

The autumnal equinox occurs at 9:29 PM CDT on September 22nd. The moon is new on September 24, which marks the following evening as the beginning of Rosh Hasanah, Jewish year 5775 AM. The crescent moon sits 2.5 degrees north of Spica, and four degrees north of Mercury on the evening of September 26th, but you may need binoculars to spot them low in twilight. The moon passes 1.2 degrees north of Saturn on September 28, and makes a fine alignment with Antares (on bottom) and Mars (in middle) on September 29th. Great photo op!

To the west, Mercury is briefly visible in evening twilight at month’s end. Venus is vanishing on the far side of the sun, lost in his glare until reappearing in the evening sky in November. Mars and Saturn are both low in the SW twilight, and Saturn will be lost behind sun next month. Jupiter dominates the early morning skies during the autumn of 2014. He rises about 3 AM at month’s end. He reaches opposition early next year, among the stars of Cancer.

The Big Dipper rides high in the NW at sunset, but falls lower each evening. Good scouts know to take its leading pointers north to Polaris, the famed Pole Star. For us, it sits 30 degrees (our latitude) high in the north, while the rotating earth beneath makes all the other celestial bodies spin around it from east to west. It is this time of year at an American Indian legend tells of the Bear and three hunters. The bowl is the bear, the three handle stars of the dipper the hunters. The first carries a bow, and has shot the bear in its flanks. The second optimistically carries a bowl on his shoulder for bear stew; look closely, and you can see the pot (Mizar. horse in Arabic, and Alcor its rider more traditionally). The last hunter carries firewood for the feast. The wound is minor, and the bear has not lost a step, but in the fall, as the bear goes into hiding along the NW horizon, the wound opens slightly, and blood oozes out to fall on the tree leaves and paint them red this time of year.

From the Dipper’s handle, we "arc" SE to bright orange Arcturus, the brightest star of Spring. Spike south to Spica, the hot blue star in Virgo. Saturn is just NW of Spica, a little brighter and more yellow in color. Note that Spica is now low in the SW, and by September’s end, will be lost in the Sun’s glare due to our annual revolution of the Sun making it appear to move one degree per day eastward. To the Greeks, Spica and Virgo were associated with Persephone, the daughter of Ceres, goddess of the harvest. In their version of "Judge Judy", the beautiful young daughter falls for the gruff, dark god of the underworld, Pluto. He elopes with her, much to the disapproval of mother Ceres, and they marry in his underworld kingdom of Hades…a honeymoon in hell…really, he does love her as well, and the marriage itself works well. But it is the reaction of Ceres that creates alarm. Very despondent over the loss of her young daughter to a fate as bad as death, Ceres abandons the crops, which wither. Soon famine sets in, and humanity appeals to Jupiter to save us all. Calling all together, Jupiter hears that Ceres wants the marriage annulled, Persephone loves them both, and Pluto wants his mother in law to stop meddling. Solomon style, Jupiter decides to split her up, not literally, but in terms of time. In the compromise (aren’t all marriages so?), when you can see Spica rising in the east in March, it means to plant your peas. For the next six months, she visits upstairs with as very happy mama, and the crops will prosper. But now, as Spica heads west (to the kingdom of death, in most ancient legends) for six months of conjugal bliss with Pluto, it is time to get your corn in the crib. This simple story, told in some form for as long as Noah’s flood, was one of the ways our ancestors 7,000 years ago knew the solar calendar and when to plant and harvest. As you watch Spica fade, thank this star for agriculture, and in a certain sense, even our own culture.

To the south, Antares rises about the same time in Scorpius. It appears reddish (its Greek name means rival of Ares or Mars to the Romans) because it is half as hot as our yellow Sun; it is bright because it is a bloated red supergiant, big enough to swallow up our solar system all the way out to Saturn’s orbit! Near the tail of the Scorpion are two fine open clusters, faintly visible to the naked eye, and spectacular in binoculars. The clusters lie to the upper left of the bright double star that marks the stinger in the Scorpion’s tail. The brighter, M-7, is also known as Ptolemy’s Cluster, since he included it in his star catalog about 200 AD.

East of the Scorpion’s tail is the teapot shape of Sagittarius, which marks the heart of our Milky Way galaxy. Looking like a cloud of steam coming out of the teapot’s spout is the fine Lagoon Nebula, M-8, easily visible with the naked eye.

The brightest star of the northern hemisphere, Vega dominates the NE sky. Binoculars reveal the small star just to the NE of Vega, epsilon Lyrae, as a nice double. Larger telescopes at 150X reveal each of this pair is another close double, hence its nickname, the "double double"…a fine sight under steady sky conditions

To the northeast of Vega is Deneb, the brightest star of Cygnus the Swan. At the other end of the "northern Cross" that makes up the body of Cygnus is Alberio, the finest and most colorful double star in the sky. Its orange and blue members are well resolved at 20X by any small scope. To the south is Altair, the brightest star of Aquila the Eagle, the third member of the three bright stars that make the Summer Triangle so obvious in the NE these clear September evenings. Binoculars should be taken to the deep sky gazes to sweep the rich portion of the Galaxy now best placed overhead in this area. They will also reveal the easiest planetary nebula to see, M-27 in Vulpecula, just south of Alberio. This fine photo of the famed "Dumbbell Nebula" reveals the double lobes of gas expelled by the dying red giant star as its core collapses to a white dwarf.

Read past issues of the Sky at Night