Day | Time (UTC) | Event |
|---|---|---|
5 | 14:32 | Venus 1.6°N of Spica |
7 | 00:52 | New Moon |
10 | 02:09 | Venus 4.1°S of Moon |
11 | 10:06 | Moon at perigee: 368,461 km (228,951 mi.) |
13 | 20:39 | First quarter of the Moon |
14 | 03:59 | Mercury 26.8°E of Sun (greatest eastern elongation) |
14 | 08:10 | Neptune at opposition |
17 | 02:37 | Saturn 3.9°N of Moon |
18 | 06:50 | Jupiter 4.1°N of Moon |
20 | 23:55 | Full Moon |
21 | 02:03 | Mercury 1.4°S of Spica |
22 | 19:21 | Autumnal (fall) equinox |
26 | 21:44 | Moon at apogee: 404,640 km (251,423 mi.) |
29 | 01:57 | Last quarter of the Moon |
30 | 14:00 | Mercury 1.7°S of Spica |
September 2021
As the summer season comes to a close, we begin to bid farewell to the wealth of objects that drape across the center of our Milky Way. But there’s still some time to soak it all in.
While Scorpius has now dipped below the horizon, Sagittarius is still visible, though low in the southwest. You also still have Jupiter and Saturn, both of which are prominent in the southern sky.
Let’s not forget to enjoy the nearest spiral galaxy to us, the Andromeda Galaxy. This is beautiful when seen either with the naked eye at a dark-sky location or alternatively, through binoculars or a small telescope.
On September 22, we welcome the fall season with the autumnal equinox.
The Moon This Month
The Moon and Venus have a close encounter on the evening of September 9 when the planet will be roughly 5 degrees southeast of the Moon.
Then, on the night of September 16, Saturn will be roughly 5 degrees north of the gibbous Moon. The next night, Jupiter will be about 6 degrees northeast of the Moon.
The new Moon occurs on September 7, with the perigee occurring on September 11. On September 20, we have the full Moon. Finally, we have the Moon at apogee on September 26, with the last quarter following three days later.
Highlights in the Southern Sky
Scorpius (the Scorpion) is now below the horizon, while Sagittarius (the Archer) is beginning to follow it in the southwestern sky.
The constellation Aquarius (the Water Bearer) is clearly visible in the southeast. An Interesting target near Aquarius that can be seen through binoculars in dark-sky locations is the Helix Nebula (NGC 7293), sometimes referred to as the Eye of God. This is a planetary nebula that formed after a star (similar to our Sun) died and shed off its outer shell of gas. What’s left behind is a small white-dwarf star. You can locate it by finding Fomalhaut in the constellation Piscis Austrinus (the Southern Fish), which will be low on the southern horizon, then looking north 10 degrees.
The constellation Capricornus (the Sea Goat) lies in the south. You’ll be able to find it quite easily this month, as Jupiter and Saturn will be situated on either side of it.
Equuleus (the Little Horse), a small constellation, can be found near Delphinus (the Dolphin), north of Capricornus. To the east of Equuleus is Messier 15, another globular cluster that can be made out through binoculars under dark skies.
To the west of Delphinus is Sagitta (the Arrow), another small constellation. Farther west of Sagitta is a wonderful asterism called the Coathanger (Collinder 399, Brocchi’s Cluster), which is best seen through binoculars or a small telescope. The asterism looks like an upside-down coat hanger and is difficult to miss.
The Summer Triangle now lies high in the south, and it is easy to see with the stars Deneb, Vega, and Altair shining brightly. The constellation Hercules has made its way to the southwestern sky, with Ophiucus (the Serpent Bearer) and Serpens (the Serpent) beginning their journey to the westward horizon. Serpens is the only constellation in two distinct parts: Serpens Caput (the Head of the Serpent) to the west of the Serpent Bearer, and Serpens Cauda (the Tail of the Serpent) to the east.
Highlights in the Northern Sky
The constellation Boötes (the Herdsman) is now low on the northwestern horizon, together with Corona Borealis (the Northern Crown).
Hercules has moved to the northwestern sky and continues to provide a fantastic opportunity to observe the globular cluster Messier 13.
Meanwhile, Ursa Major (the Great Bear) is almost due north, with the Big Dipper asterism closer to the horizon. At the beginning of the month, the constellation Auriga (the Charioteer) is below the northeastern horizon, but by the end of the month, it begins its northward journey, with its star Capella shining brightly near the horizon.
Perseus is in the northeast, and the Double Cluster (NGC 869 and NGC 884) sits between this constellation and Cassiopeia. The “house” that is Cepheus now appears upside-down in the north.
Mirfak, the brightest star in Perseus, is beautiful when seen through binoculars, particularly as there is a cluster of many bright stars in view, known as the Alpha Persei Association (Melotte 20).
And of course, it’s always worth observing the Andromeda Galaxy (Messier 31), whether it’s with the unaided eye in dark-sky conditions or through binoculars or a telescope.