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The Night Sky of September

Dr. Wayne Wooten
Professor of Astronomy

For September 2016, the moon will be new on September 1st. The waxing crescent moon will pass just north of Jupiter and Mercury to following evening, but since they are only 17 degrees east of the Sun, binoculars may be needed to spot this nice grouping. On September 3rd, the moon passes a degree north of much brighter Venus in the SW. The crescent moon next passes 4 degrees north of Saturn on September 8th, and at first quarter the following evening, passes 8 degrees north of reddish Mars. The full moon, the Harvest Moon, is on September 16th, and barely grazes the earthís faint penumbral shadow. This eclipse will be over before moonrise at sunset locally. The autumnal equinox begins fall at 9:21 AM CDT on September 22nd. The last quarter moon rises at midnight on September 23rd.

To the west, Mercury and Jupiter are briefly visible in evening twilight at monthís start, but both are lost in the Sunís glare for most of September; Mercury does return to the dawn sky at the end of the month, reaching greatest western elongation on September 28th. Venus is climbing higher in the western sky each evening, and is a brilliant but tiny featureless gibbous disk in the telescope, still on the far side of the sun now. To the south, Saturn lies about 6 degrees north of red Antares in Scorpius, while a little east of it, Mars is fading and moving rapidly eastward daily from Scorpius into Sagittarius by the end of the month.

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 Dipperís 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 Septemberís end, will be lost in the Sunís 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 HadesÖa honeymoon in hellÖreally, 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 (arenít 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 Noahís 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 marks the heart of 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 Saturnís orbit! Saturn sits about 6 degrees north of Antares this fall. 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 Scorpionís tail. The brighter, M-7, is also known as Ptolemyís Cluster, since he included it in his star catalog about 200 AD.

East of the Scorpionís 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 teapotís spout is the fine Lagoon Nebula, M-8, easily visible with the naked eye. Many other clusters and nebulae lie toward the galactic center, and are shown on the SkyMap chart and discussed on its binocular and telescope object listing on page 2.

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". This is fine sight under steady seeing conditions over 150X with scopes 4" or larger. Our featured object of the month lies at the other end of the parallelogram of Lyra, between the two bottom stars; the Ring Nebula, marked "M-57" on the Skymap, is a smoke ring of gas and dust expelled by a dying red giant star while its core collapsed to a white dwarf. A similar fate is expected for our own sun in perhaps five billion more years. This photo with an 8" telescope is by Steve Gomez of the EAAA. While the ring is visible in small scopes, the tiny faint white dwarf shows up well in photos, but visually is much harder, taking really large scopes to reveal.

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.

September sky at night

Professor Wayne Wooten

For September 2016, the moon will be new on September 1st. The waxing crescent moon will pass just north of Jupiter and Mercury to following evening, but since they are only 17 degrees east of the Sun, binoculars may be needed to spot this nice grouping. On September 3rd, the moon passes a degree north of much brighter Venus in the SW. The crescent moon next passes 4 degrees north of Saturn on September 8th, and at first quarter the following evening, passes 8 degrees north of reddish Mars. The full moon, the Harvest Moon, is on September 16th, and barely grazes the earthís faint penumbral shadow. This eclipse will be over before moonrise at sunset locally. The autumnal equinox begins fall at 9:21 AM CDT on September 22nd. The last quarter moon rises at midnight on September 23rd.

To the west, Mercury and Jupiter are briefly visible in evening twilight at monthís start, but both are lost in the Sunís glare for most of September; Mercury does return to the dawn sky at the end of the month, reaching greatest western elongation on September 28th. Venus is climbing higher in the western sky each evening, and is a brilliant but tiny featureless gibbous disk in the telescope, still on the far side of the sun now. To the south, Saturn lies about 6 degrees north of red Antares in Scorpius, while a little east of it, Mars is fading and moving rapidly eastward daily from Scorpius into Sagittarius by the end of the month.

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 Dipperís 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 Septemberís end, will be lost in the Sunís 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 HadesÖa honeymoon in hellÖreally, 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 (arenít 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 Noahís 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 marks the heart of 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 Saturnís orbit! Saturn sits about 6 degrees north of Antares this fall. 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 Scorpionís tail. The brighter, M-7, is also known as Ptolemyís Cluster, since he included it in his star catalog about 200 AD.

East of the Scorpionís 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 teapotís spout is the fine Lagoon Nebula, M-8, easily visible with the naked eye. Many other clusters and nebulae lie toward the galactic center, and are shown on the SkyMap chart and discussed on its binocular and telescope object listing on page 2.

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". This is fine sight under steady seeing conditions over 150X with scopes 4" or larger. Our featured object of the month lies at the other end of the parallelogram of Lyra, between the two bottom stars; the Ring Nebula, marked "M-57" on the Skymap, is a smoke ring of gas and dust expelled by a dying red giant star while its core collapsed to a white dwarf. A similar fate is expected for our own sun in perhaps five billion more years.

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.

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