September Night Sky Guide: Best Constellations and Stars to Spot
Don’t miss out! Here are 10 constellations best visible on September evenings. Whether you use our Star Walk 2 app’s augmented-reality sky map or a classic star chart, here’s your go-to sky guide for September stargazing.
Contents
- Introduction
- Bright September constellations
- Faint September constellations
- Pro tips for astronomical observations
- More to see in the September night sky
- Bottom Line: Constellations best visible in September
Introduction
Welcome to our monthly series on the best constellations to observe! In September, among the best visible constellations are Aquila, Cygnus, Capricornus, and Pavo.
We have organized the 88 officially recognized constellations into twelve groups, one for each month, based on when they’re best visible in the sky. A constellation is considered “best visible” during the month in which it crosses the local meridian at around 9 p.m. In other words, this is the month in which the constellation reaches its highest point in the sky (culmination) at around 9 p.m. local time.
Now, let’s dive into September’s top constellations, listed from the brightest (☆☆☆) to the faintest (☆). To find any of these constellations in just a few seconds, use the free Star Walk 2 astronomy app.
Bright September constellations
Aquila
- Brightness: ☆☆☆
- Visible from: 85°N to 75°S
- Brightest star: Altair (mag 0.8)
- Best deep-sky objects: Glowing Eye Nebula (mag 12), NGC 6709 (mag 6.7)
How to find Aquila in the September night sky
Aquila forms one corner of the Summer Triangle with the other two corners formed by Lyra (Vega) and Cygnus (Deneb). The Milky Way crosses the constellation.
In the Northern Hemisphere, look high in the south for Altair. Two nearby stars, Tarazed and Alshain, sit on either side of Altair in a short line and form the “head” of the Eagle. Follow the Milky Way to the south to trace Aquila’s elongated shape.
In the Southern Hemisphere, face north after dusk. Altair stands about mid-sky. Use the Milky Way as a guide — the constellation lies along this starry band. The small constellations Sagitta and Delphinus are close by and help with star-hopping.
Discover more fascinating facts about Aquila in our dedicated article.
Myth of the Aquila constellation
In Greek mythology, Aquila is the eagle of Zeus. It carries the god’s thunderbolts and serves as his messenger. In one story, the eagle lifts Ganymede to Olympus, where the youth becomes the cupbearer of the gods.
Another story tells how the eagle torments Prometheus; Heracles frees him by shooting the bird with an arrow — the nearby constellation Sagitta. To honor the creature and preserve these tales, the gods placed the Eagle among the stars.
Cygnus
- Brightness: ☆☆☆
- Visible from: 90°N to 40°S
- Brightest star: Deneb (mag 1.2)
- Best deep-sky objects: Veil Nebula (mag 7), North America Nebula (mag 4)
How to find Cygnus in the September night sky
Cygnus is easy to recognize in the sky because its stars make up the Northern Cross asterism that lies along the Milky Way. The asterism consists of the brightest stars in Cygnus: Deneb, Sadr, Gienah, Delta Cygni, and Albireo. The “head” of the cross, Deneb, is also part of the Summer Triangle asterism. In the pattern of the constellations, Deneb marks the tail of the swan, and Albireo marks the beak.
In the Northern Hemisphere, look high overhead after dusk. Find bright Deneb, then follow a straight line through Sadr to Albireo. This long line points roughly toward Altair in Aquila.
In the Southern Hemisphere, face north. The Northern Cross tilts on its side low above the horizon. Use the Milky Way band to trace the swan’s wings.
Myth of the Cygnus constellation
One well-known myth tells of Cycnus, a friend (or relative) of Phaethon. After Phaethon lost control of the Sun’s chariot and fell to Earth, Cycnus searched the river for his body and mourned him. The gods took pity and changed Cycnus into a swan, so he could glide over the waters. They then placed the swan among the stars as Cygnus. Another myth says the swan is Zeus in disguise. Zeus took the form of a swan to approach Leda. From this union came famous children, including Helen of Troy.
Capricornus
- Brightness: ☆☆
- Visible from: 60°N to 90°S
- Brightest star: Deneb Algedi (mag 2.8)
- Best deep-sky objects: Messier 30 (mag 7.5)
How to find Capricornus in the September night sky
Capricornus sits between Sagittarius and Aquarius along the zodiac. Capricornus is one of the faintest zodiac constellations, so choose a clear, dark night or, if your sky is bright, take binoculars and try to spot individual stars in the constellation.
To find Capricornus, look for a wide triangle in the sky — one tip is marked by the star Algedi, sometimes called Giedi; another is the brightest star in the constellation, Deneb Algedi. The 7th brightest star in the constellation, ω (Omega) Capricorni, completes this triangle.
In the Northern Hemisphere, face south in the early evening. The triangle sits low above the horizon.
In the Southern Hemisphere, look high in the north. The triangle of stars will be above the Aquila constellation.
Myth of the Capricornus constellation
Capricornus is the sea-goat — half goat, half fish. In one Greek myth, it is linked to the god Pan. When the monster Typhon attacked the gods, Pan leapt into a river to escape. The part above the water stayed a goat; the part below became a fish. After the danger passed, Zeus honored this clever transformation by placing the sea-goat in the sky.
Pavo
- Brightness: ☆☆
- Visible from: 15°N to 90°S
- Brightest star: Peacock (mag 1.9)
- Best deep-sky objects: NGC 6752 (mag 5.4)
How to find Pavo in the September night sky
Southern observers have the advantage here. From the Southern Hemisphere, face south on a dark moonless night. Look east of Triangulum Australe and south of Indus for the bright star Peacock.
From most Northern Hemisphere locations, Pavo doesn’t rise above the horizon. And in places where it’s visible, it sits very low above the southern horizon; a flat, unobstructed horizon helps.
Myth of the Pavo constellation
Pavo is named for a peacock in Greek mythology and honors Hera’s sacred bird. When Hera — queen of the gods — nearly caught Zeus together with Io, Zeus turned Io into a white cow. Hera set the hundred-eyed giant Argus to guard her. At Zeus’s command, Hermes lulled Argus to sleep and killed him. Hera then placed Argus’s eyes on the peacock’s tail.
Pavo itself is not an ancient Greek constellation; it was added to southern star maps by 16th-century explorers and cartographers. The name keeps the mythic link: the sky’s peacock honors Hera’s bird.
Faint September constellations
Indus
- Brightness: ☆
- Visible from: 25°N to 90°S
- Brightest star: Alpha Indi (mag 3.1)
- Best deep-sky object: NGC 7049 (mag 10.6)
Delphinus
- Brightness: ☆
- Visible from: 90°N to 70°S
- Brightest star: Rotanev (mag 3.6)
- Best deep-sky object: NGC 6934 (mag 9.7)
Sagitta
- Brightness: ☆
- Visible from: 90°N to 70°S
- Brightest star: Gamma Sagittae (mag 3.5)
- Best deep-sky object: Angelfish Cluster (mag 8.2)
Equuleus
- Brightness: ☆
- Visible from: 90°N to 70°S
- Brightest star: Kitalpha (mag 3.9)
- Best deep-sky object: NGC 7040 (mag 15)
Vulpecula
- Brightness: ☆
- Visible from: 90°N to 55°S
- Brightest star: Anser (mag 4.4)
- Best deep-sky objects: Dumbbell Nebula (mag 7.4), NGC 6940 (mag 6.3)
Microscopium
- Brightness: ☆
- Visible from: 45°N to 90°S
- Brightest star: Gamma Microscopii (mag 4.7)
- Best deep-sky object: NGC 7060 (mag 13.7)
Pro tips for astronomical observations
- Best time: 9 p.m.–2 a.m. local time. In the Northern Hemisphere (early autumn), darkness arrives earlier than in midsummer. In the Southern Hemisphere (early spring), evenings are still long and dark.
- Moon phase: Plan observations around the New Moon on September 21, 2025. Nights from Sept 20–22 are best for faint nebulae like the Veil and North America Nebula.
- Learn more: For all the astronomical events happening in September, check our September Night Sky Guide. Learn how to identify the most famous stars — Polaris, Sirius, Arcturus, and many others — with our infographic.
More to see in the September night sky
- The Summer Triangle (Vega, Deneb, and Altair) is visible in the evening sky. Use it as a giant pointer: Deneb marks the location of Cygnus, Altair marks Aquila, and between them lie Sagitta, Delphinus, and Vulpecula.
- The Milky Way is still spectacular: sweep binoculars through Cygnus and Aquila to pick out dark lanes and star clouds.
- September is the best time to see the Andromeda Galaxy (M31). In early September, look in the mid-evening. By late September and early October, M31 is in the east at nightfall, high overhead around midnight, and high in the west before dawn. You can try to see it with the naked eye under dark skies; binoculars make it easier.
- 2025 Blood Moon: a total lunar eclipse occurs on September 7. Billions of people in Australia, Europe, Africa, and Asia will witness the Moon turning red in the sky. Read our guide to learn if the Blood Moon will be visible from your location.
- Another eclipse will take place in September 2025! Apartial solar eclipse happens on September 21 near the equinox, mainly visible at sunrise in the far Southern Hemisphere (e.g., New Zealand, South Pacific, Antarctica). Check out the dedicated article and see when and where the “Equinox Eclipse” will be visible.
Bottom Line: Constellations best visible in September
September nights offer bright showpieces as well as fainter targets. Look for the eagle Aquila, the swan Cygnus, the sea-goat Capricornus, and the southern peacock Pavo along the Milky Way. Each constellation brings its own story — remember that while looking at the sky! Aim for moonless evenings around September 21 and use the free Star Walk 2 app for easy navigation.
