What’s Up in the Sky – September, 2019
September is Again a Good Time to Observe
I have often said September is a good month for observing, and this year is no exception with the addition of two bright planets to the myriad of sights for both the eye and the telescope.
Let’s begin with the constellation Scorpius. Looking low toward the southwest horizon, it will be easy to find because Jupiter will be shining brightly right above it. Just below Jupiter look for Antares, the brightest star in Scorpius and sometimes referred to as the heart of the scorpion. It earned that honor because of its dull, reddish appearance to the naked eye. It is actually a type M red supergiant star, 550 light years away, which is a good thing because it is well over 10,000 times brighter than the Sun.
To the left of Scorpius is Sagittarius, one of the easiest constellations to recognize, or at least part of it is. Sagittarius, the Archer, is actually one of two centaurs in the sky, a creature that is half-man, half-horse, with his arrow pointed toward the scorpion. But the grouping of visible stars clearly outlines a teapot, with its handle on the left and spout on the right. On a clear, dark night, you can see the Milky Way rising up like steam from the spout. The bright object just above the handle is the planet Saturn. Scan the area with binoculars or a small telescope to see a myriad of deep-sky objects.
Immediately above Scorpius is the constellation Ophiuchus, the “serpent-bearer” or, more simply, a man grasping a snake. I mention this constellation not for observational value, but for its historic record. In 1604 a bright, new star flared up in the constellation. For several months the star was brighter than any other star in the sky and even brighter than Jupiter. Coincidently, both Jupiter and Saturn were very close by, and the three formed a compact, distinct grouping.
The “new star”, actually a supernova, was studied extensively by the astronomer Johannes Kepler for about 18 months before finally fading from sight, and is now known as “Kepler’s Star”. It was the last supernova to be observed in our galaxy.
Now still facing south, look straight overhead. There you will see the Summer Triangle which, like the Teapot, is an asterism, a prominent pattern of stars that is not a constellation. The brightest, Vega, is in Lyra, the Lyre, recognizable as a small parallelogram with an equilateral triangle on top. To the left of Vega is Deneb, the tail of the swan, Cygnus. Directly below these two is Altair, in the constellation Aquila, the Eagle.
Scan Lyra with binoculars to observe several double stars. Cygnus actually looks like a cross and is sometimes referred to as the “Northern Cross”. Aim a small ‘scope or binoculars at Albireo, the star at the bottom of the cross (the head of the swan) and you will see a double star with components of different colors. Can you tell why it is sometimes referred to as the “U of M” star?
If you are fortunate enough to observe from a dark site, you will see that the Milky Way stretches all the way across the sky, from the spout of the Teapot, overhead through Cygnus, and down through Cassiopeia in the northeast. Along this “river of light” can be found many wonders up in the sky.
This month in history:
Sept. 1: Pioneer 11 is first spacecraft to fly past Saturn – 1979
Sept. 3: Last two Apollo Moon landings canceled by NASA – 1970
Sept. 8: Voyager 1 launched – 1977
Sept. 20: Wernher von Braun arrives in US – 1945
Sept. 21: Galileo mission ends – 2003
Sept. 23: Carolyn Herschel discovers NGC 253 – 1783
Sept. 25: 59 – day Skylab 3 mission ends – 1973
Sept. 30: End of daily communication with Pioneer 11 – 1995
