Night sky highlights - September 2026

Spot Neptune through a telescope, see the Moon in the Beehive Cluster, and mark the autumnal equinox and equilux.

By Avneil (work experience student) and Jess Lee, Royal Observatory astronomer

Top 3 things to see in the night sky in September 2026

• 8 September – see the Moon in the Beehive Cluster  
• 25 September – mark the equilux, with equal hours of light and dark  
• 26 September – catch Neptune at opposition

The equinox and equilux

The Sun will cross the celestial equator on 23 September, moving from the northern to the southern half of the sky. This event, known as the autumnal equinox, marks the beginning of autumn in the Northern Hemisphere. 

Interestingly, the idea that the equinox is a day with equal daylight and nighttime hours is not strictly correct. We receive approximately 12 hours of daylight and 12 hours of darkness on the equinox, but not exactly! 

In London, for example, the Sun will rise at 6.48am and set at 6.56pm on the 23rd, meaning we get 12 hours and 8 minutes of daylight. The day where daylight hours and nighttime hours are equal occurs a few days after the equinox and is known as the equilux. 

The day on which the equilux falls depends on the latitude of a particular region, and for us in the UK it will be September 25.

Meteor shower challenges

September will bring us two minor meteor showers. Neither are favourable to view this year, with the Moon’s light washing out the sky at the start of the month and a very low hourly meteor rate for both. However, they have fascinating stories to keep you warm whilst you wait for a glimpse of a shooting star. 

The first of these is the Aurigids meteor shower. This meteor shower will be active from 28 August until 5 September, peaking on the 1st. Its radiant point (the point from which the shower appears to originate) is located within the constellation of Auriga. This constellation resembles a charioteer holding a goat. The charioteer is linked to the Athenian King Erichthonius, who is believed to have created the four-horse chariot, and was placed into the sky as a reward. 

The goat, on the other hand, is linked to Amalthea, a goat who raised the infant Zeus when he was hiding from his father Cronos. The shower produces bright meteors, but they are quite rare, occurring at a peak rate of only 6 meteors per hour. However, the shower has previously had outbursts, such as in 1935, 1986, 1994 and 2007, so you might just get lucky.

The second is the Epsilon Perseids meteor shower, which is active for much longer, from 5 September until 21 September, peaking on the 9th. The radiant point of the shower is located within the constellation Perseus, near the star Algol, which is fascinating in its own right. 

The star is nicknamed 'The Demon Star' because it regularly dims and brightens again, similar to a winking eye. In Arabic tradition it was linked to a ghoul, and to a Gorgon in the Greek tradition. This is because Algol is in fact not a single star, but rather a triple star system in which the stars regularly eclipse each other, creating the fluctuations in brightness. The shower itself contains fast-moving meteors, but they are quite infrequent, appearing at a rate of 5 meteors per hour at the peak.  

Neptune at opposition

On 26 September, Neptune will be at a point in its orbit where Earth will be positioned directly between it and the Sun. This is known as opposition. Opposition will make it easier for us to see Neptune because it is at its closest and brightest.

However, due to Neptune's distance, it will still not be visible with the naked eye, and must instead be viewed through a telescope. Have a look in the constellation of Pisces to find it.  

Whilst you’re admiring Neptune, you could also try to spot Triton, Neptune’s biggest moon. Triton is one of the most interesting objects in our Solar System. It is named after the son of the Greek god of the ocean, Poseidon, whose Roman counterpart gives Neptune its name. 

One of Triton's most distinctive features is that it orbits Neptune in retrograde, meaning it revolves around the planet in the opposite direction to Neptune's other moons. This unusual orbit has led to the hypothesis that Triton did not form in Neptune's orbit, but was instead a dwarf planet that was captured by Neptune's gravity.

Another thing that makes this moon particularly unique is that it has one of the coldest recorded temperatures in the entire Solar System, reaching temperatures as low as −240°C. Triton's surface is also home to cryovolcanoes. These are volcanoes on the surfaces of very cold celestial bodies which, instead of lava, erupt an icy slush of materials such as water and ammonia.

If you want an easier planet to spot, Saturn will be in the sky all month long and bright enough to see with just your eyes, below the square of Pegasus, although you’ll need a telescope to see its beautiful rings.

Lunar encounter of the Beehive Cluster

On 8 September a lunar occultation of M44, otherwise known as the Beehive Cluster, will take place. This will last from roughly 4am until sunrise.

If you happen to be awake, look towards the east, ideally with a pair of binoculars. You’ll see a thin crescent Moon moving in front of this beautiful open star cluster. The Beehive Cluster is a group of roughly 1,000 stars loosely bound together, located in the constellation of Cancer. 

The name M44 indicates that the cluster is part of the Messier catalogue. This is a catalogue of astronomical objects created by French Astronomer Charles Messier.

Messier was hoping to observe and track comets, but he would sometimes come across fuzzy, distant objects. As telescopes at the time were not powerful enough for him to understand what these objects were, Messier catalogued them so time would not be wasted on observing them. This list is today known as the Messier catalogue, and M44 is the 44th entry.

The square of Pegasus

Throughout September the constellation of Pegasus will climb higher in the eastern sky, making it easier to see regardless of the trees and buildings you might have on your horizon.

To find this constellation, first look for the ‘square of Pegasus’, an asterism made up of the four stars Markab, Scheat, Algenib and Alpheratz. These four, along with Enif, the star marking the nose of the horse, are the brightest and easiest to spot.

Pegasus refers to the winged horse from Greek mythology, who sprang up from the blood of the Gorgon Medusa when she was defeated by the hero Perseus. Viewers in the Northern Hemisphere see the horse upside down, and so we’ll have to imagine him doing some particularly impressive flying tricks.

Other interpretations of this square include a field (ancient Mesopotamian astronomy) and a bedstead for the Moon (Hindu astronomy). Maybe you’ll create something new when you spot the square for yourself.

The Moon's phases in September 2026

• Last quarter – 4 September 
• New moon – 11 September 
• First quarter – 18 September
• Full moon – 26 September

Stargazing tips

When looking at faint objects such as stars, nebulae, the Milky Way and other galaxies, it is important to allow your eyes to adapt to the dark so that you can achieve better night vision.

Allow 15 minutes for your eyes to become sensitive in the dark, and remember not to look at your mobile phone or any other bright device when stargazing.

If you're using a stargazing app on your phone, switch on the red night vision mode.

Header image: M44 - The Beehive Cluster © Weitang Liang, Qi Yang - shortlisted in ZWO Astronomy Photographer of the Year 2025