For September 2023, the waning gibbous moon sits just to the right of brighter Jupiter on September 5. The last quarter moon is September 6. The waning crescent moon lies to the upper left of bright Venus in the dawn on September 11. The new moon is on September 14, exactly a month before the annular eclipse in October. More on it next month! The first quarter moon is on September 22. The next day, fall begins with the Autumnal Equinox at 1:50 a.m. CDT. September 26. The waxing gibbous moon passes below Saturn in the southeast dusk on September 26. The Full Moon, the Harvest Moon, will be on September 29. Mercury lies too close to the Sun for visibility from Earth this month but will emerge at dusk in October. But Venus is back, now west of the rising sun in the dawn, and dominating the morning skies. She is 28% sunlit and at her brightest on the morning of September 19.
Mars is lost on the far side of the Sun this month. Jupiter reaches opposition in early November and rises about 10 p.m. in the northeast in Taurus at midmonth. But Saturn is at its best this month, reaching opposition on August 26, rising in the southeast at sunset. For a detailed map of northern hemisphere skies visit Skymaps.comand download the map for September 2023.
To the northwest, we find the familiar Big Dipper getting lower each evening. Most know how to use the two-pointers at the lower part of the bowl to find Polaris, our Pole Star, sitting about 30 degrees high all night in the northern sky for the Gulf Coast. From the Dipper’s handle, we “arc” southeast to bright orange Arcturus, the brightest star of Spring, and still well up in the western twilight. Spike south to Spica, the hot blue star in Virgo. Note that Spica is now low in the southwest, 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.
When you can see Spica rising in the east in March, it means to plant your peas. 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. As you watch Spica fade, thank this star for agriculture, and even our own civilization. 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 Saturn’s orbit.
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 to the naked eye. 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. The brightest star of the northern hemisphere, Vega dominates the northeast sky. Binoculars reveal the small star just to the northeast 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 a fine sight under steady-seeing conditions over 150X with scopes 4” or larger. Between the two bottom stars; the Ring Nebula, marked “M-57” on the Skymap, is a 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. It was just NW of it that I discovered the brightest nova of my lifetime, Nova Cygni, on August 27, 1975. Here a shell of hydrogen around a white dwarf exploded suddenly, becoming a record (for a nova, at least) 20 million times brighter in a matter of hours. It went from not visible in any telescope to the sixth brightest star in the summer sky in less than a day, and I was looking at the right place and time to catch it still on the rise.
The Escambia Amateur Astronomers return to Casino Beach for our Pavilion Stargaze Season on the first quarter moon. Meet us south of the famed Beach Ball Water Tower and bring your smartphone to image the Sun (before sunset with our solar scopes), Moon, and constellations. We have free star charts and will show you what’s up. The gazes, if clear skies permit, will be on Fridays and Saturdays for September 22-23. For deep skies with much less light pollution, on the weekends of the third quarter moon, we continue our cooperation with the Florida State Parks at Big Lagoon State Park. Here the emphasis is on learning to observe and photograph the night sky with binoculars or your own telescopes and smartphones or other cameras. While the Pavilion parking is free, normal entry fees to Big Lagoon still apply, and remember to check in the front gate before it closes at sunset. Our gazes for best imaging of the Milky Way, constellations, and other galaxies are on September 9, and October 7. Clear skies permitting! For more information on the Escambia Amateur Astronomers, join us on Facebook, or contact our sponsor, Lauren Rogers at Pensacola State at lrogers@pensacolastate.edu.
