The moment the leaves begin to turn, we know the real show is about to begin. October marks the definitive arrival of the autumn skies in Luxembourg, and the best time of the year for serious observers.
The days shorten, the nights grow longer, and the brilliant patterns of summer finally begin their slow retreat into the west. It’s a month of profound transition, with massive galaxies taking centre stage and meteor showers adding a touch of drama.
The Triangulum Galaxy
While the grand Andromeda Galaxy (M31) usually steals the show in autumn, its smaller, fainter neighbour is equally worth seeking out.
The Triangulum Galaxy (Messier 33) is a key member of our galactic Local Group, approximately 2.7 million light-years away. Though smaller than both Andromeda and the Milky Way (at about 60,000 light-years across), it’s still home to tens of billions of stars.
We see M33 almost face-on from Earth, which allows us to admire its loosely wound spiral arms, dotted with bright patches of star formation.
The most famous is NGC 604, a colossal stellar nursery nearly 1,500 light-years wide, vastly larger than the famous Orion Nebula in our own galaxy. These intense regions give the Triangulum its delicate, mottled appearance in long-exposure photographs.
Visually, M33 is a challenge. As its light spreads over a vast area, its surface brightness is very low. Under Luxembourg’s darkest rural skies, particularly in the north of the country, it can sometimes be glimpsed with the naked eye, but binoculars or a small telescope are your best bet.
Look for a soft, oval glow just south of the Andromeda constellation. With patience and truly dark conditions, it rewards the observer with a feeling of awe: a direct sight of another entire galaxy, far beyond our own.
October’s Finest
There are two meteor showers to keep an eye on this month. The Draconids peak on the evening of October 7th; they’re usually modest but are famous for rare outbursts in the past. They radiate from the constellation Draco (as the name suggests) and are best seen in the early evening.
Later in the month, the swift Orionids arrive, peaking on the night of October 21st–22nd. These meteors are the remnants of the legendary Halley’s Comet and can produce around 20 meteors per hour under dark skies. Both are best observed from dark locations, away from city lights.
Keep a close watch on the Moon this month, as its phases dictate our deep-sky viewing windows. The New Moon arrives late on October 21st, treating us to the darkest skies perfect for spotting faint, far-off galaxies. Earlier, on October 6th, the sky will be dominated by the glorious Hunter’s Moon. This beautiful name comes from Native American traditions, as this was the first full moon after the harvest, historically signalling the crucial time to hunt and preserve food before winter.
Astronomically, the Hunter’s Moon is unique because it rises much closer to sunset for several nights, providing extended evening light, a true boon for ancient hunters. However, for us modern observers, its brightness will unfortunately wash out the most delicate celestial targets for several nights.
The Planets over Luxembourg
Saturn remains well placed in Aquarius, high in the south by mid-evening. Grab a small telescope, as its stunning rings are still perfectly visible. By month's end, the King of the Planets, Jupiter, will dominate the sky, rising earlier each night near Aries and Pisces. Even a small telescope will reveal its dazzling moons. Venus continues its brilliant reign as the Morning Star just before sunrise whereas Uranus reaches opposition on October 6th, technically making it visible with binoculars, though it remains a challenging target.
Constellations: The Autumn Classics
The majestic Summer Triangle (Vega, Deneb, Altair) still lingers overhead in the early evening but finally dips westward as the season advances. In the east, the great autumn constellations take over: Pegasus with its vast, easy-to-spot square; Andromeda hosting the famous homonym galaxy; and Cassiopeia, the iconic “W” high in the north, which is rich in star clusters.
October is a month of change and richness in the night sky. The Milky Way fades earlier each evening, but in exchange, the great autumn spiral galaxies climb higher. Among them, the Triangulum Galaxy may not dazzle at first glance, but for those who take the time to find it, it offers a profound reward.
Grab your binoculars, get outside, and see three million years of light for yourself this month.
