September Celestial Splendor!
Sadly summer comes to an end this month, but the great news for stargazing in September is that there’s still plenty of great summer constellations, and with the early sunsets you can get an earlier start in the evening.
The full moon this month is on September 14th and because of its proximity to the Autumnal Equinox it’s officially the Harvest Moon for 2019. What makes the full harvest moon so special is that because of the unique celestial mechanics this time of year, the moon rises only about 20 minutes later each evening, making the full moon seem to “last longer”. Normally the full moon rises from 35 to nearly 60 minutes later each night.
The brightest “star” in the evening sky is actually the giant planet Jupiter still dazzling in the south-southwest. On September 5th the first quarter (half) moon will be parked just to the upper right of Jupiter in a really sweet celestial hug! As the month begins Jupiter is just over 471 million miles from Earth. It’s a true celestial gem through even a small telescope or binoculars. You can resolve the disk of the 88,000-mile diameter planet, and you might even see some of Jupiter’s cloud bands. For sure you’ll see up to four of Jupiter’s brightest moons that appear as tiny “stars” on either side of Jupiter.
The next brightest star-like object to the left of Jupiter is Saturn in the south southwestern early evening. It’s simply wonderful to gaze upon through a small telescope. You can easily see its famous ring system that spans over 136,000 miles in diameter as well as its moons, especially Titan that’s larger than the planet Mercury. At the start of the month Saturn is just under 879 million miles from our wonderful world. On September 7th the waxing gibbous moon will be perched just to the right of Saturn, and on the 8th the moon will be just to Saturn’s left. It’s a show not to miss!
Nearly overhead in high southern sky is the “Summer Triangle”. Just look for the three brightest stars you can see around the zenith and that’s it. All three stars are the brightest stars in each of their respective constellations. Vega is the brightest star in the constellation Lyra the Harp. Altair is the brightest in Aquila the Eagle, and Deneb is the brightest star in Cygnus the Swan, also known as the “Northern Cross”.
The Big Dipper is proudly hanging by its handle in the northwest evening sky. The Big Dipper itself isn’t an official constellation but does outline the rear end and tail of the great constellation Ursa Major, The Big Bear. The fainter Little Dipper, otherwise known as Ursa Minor the Little Bear, is standing on its handle to the right of the Big Dipper with Polaris, the North Star, at the end of its handle.
If you follow the curve of the Big Dipper’s handle beyond the end of the handle, you’ll run right into the super bright orange tinged star Arcturus. That’s the brightest shiner in the constellation Bootes the Herdsman that looks much more like a giant upright celestial kite in the western sky with Arcturus stationed at the tail.
In the northeast sky look for the sideways “W” that outlines the throne of Cassiopeia the Queen. Just to the upper left of the queen in the northern sky look for the faint upside-down house with the steep roof, which is supposed to be Cepheus the King.
The great autumn constellation Pegasus the winged horse is on the rise in the eastern sky after sunset. Look for the big diamond of stars that outlines the torso of Pegasus. This is called the “Square of Pegasus”, but because of the way it’s positioned in the sky this time of year it’s also known as the “Autumn Diamond.”
Attached to the left side of the Diamond is the constellation Andromeda the Princess, and within the constellation is the Andromeda Galaxy. You should be able to spot it with binoculars or a small telescope, appearing as a faint patch of light. If your skies are dark enough you may even see it with your unaided eyes. The Andromeda Galaxy, a next-door neighbor of our Milky Way Galaxy, is more than two million light-years away with just one light year equaling nearly six trillion miles!
Speaking of our Milky Way, there’s a very distinct constellation to the lower right of Saturn in the early evening sky that really looks like a teapot! That’s the brightest part of the larger constellation Sagittarius the Archer. If you’re stargazing in the dark countryside you’ll see a milky band of light that reaches across the entire sky from around the spout of the teapot all the way to Cassiopeia in the northeast.
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul, and is author of the book, “Stars, a Month by Month Tour of the Constellations” published by Adventure Publications. Available at bookstores and online at www.adventurepublications.net.
If you have any astronomical questions or want me to write about something you’re seeing in the night sky drop me a line at firstname.lastname@example.org