The Sky in June 2025

In June, the constellation Serpens crosses the meridian at midnight throughout Europe: its head (Serpens Caput) culminates around 11 p.m. local time around June 15 for mid-latitudes (45–55° N), while the tail (Serpens Cauda) passes to the south about an hour later. Visibility is excellent from most European countries, from Portugal to Poland. Dominated by the orange star Unukalhai (α Ser, mag ≈ 2.6), the constellation is full of remarkable objects: the globular cluster M 5, the Eagle Nebula M 16, the vast open cluster IC 4756, and some spectacular galaxies like NGC 5921 and the Seyfert Sextet. Whether you observe with binoculars, a small refractor, or a large photographic tube, you're sure to find wonder under this early summer sky.

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1. Overview of the Constellation

Locating Conditions

• Altitude: the head reaches ~35° in the south at 50° N; even higher further south.
• Late twilight: true astronomical night falls after 11 p.m. CEST at 50° N; plan to observe the tail after midnight.

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2. Custom Path Based on Your Equipment

2.1 Binoculars (8×40 – 10×50)

• θ Serpentis: comfortable separation, beautiful white hues.
• M 5 (mag 5.6): appears like a cottony cloud; dark sky essential.

2.2 Small Refractor 80–100 mm

• M 16 “Eagle Nebula”: cluster NGC 6611 is clear, nebulosity appears with a UHC filter.
• δ Serpentis: tight double requiring good magnification (> 120×).

2.3 Telescope 150–200 mm

• IC 4756 (mag 4.6): over 80 stars scattered in a 1.5° field.
• NGC 5921 (mag 11.5): central bar clear under dark skies; spiral arms visible from 200 mm.
• Companion galaxies: NGC 5970 & 6118 already show elliptical disks.

2.4 Large Aperture / Astro-Photography (> 250 mm or assisted viewing)

• M 5: resolve the core of the cluster — a true stellar “firework.”
• Seyfert Sextet (HCG 79): cluster of six intertwined galaxies 190 Mly away. A challenge even for modern deep-sky cameras.
• Dark tendrils of M 16: capture your own “Pillars of Creation” using stacked short exposures.

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3. Visibility Window (Latitudes 45°–55° N)

(Shift ±1 hour depending on your longitude/time zone position.)

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4. Practical Tips Across the Continent

1. Seek a clear southeast horizon: the tail is low in Northern Europe.
2. Filter light pollution: a CLS or UHC filter greatly enhances M 16 in suburban skies.
3. Atmospheric stability: favor nights with low jet stream; globular resolution depends heavily on seeing.
4. Wide-field astro-photography: a 135 mm f/2 lens captures IC 4756, NGC 6633 and the serpentine Milky Way at once.
5. Assisted viewing: with a color camera like the 533c, structures in the Sextet or NGC 5921 arms become visible in a few seconds.

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5. Going Further

• Interactive Stellarium maps (free) to simulate your nights based on your location.
• Mobile ephemerides (SkySafari, Stellarium Mobile) to adapt passage times to your time zone.
• Monthly observing guides: subscribe to our newsletter to receive monthly object selections and recommended accessories.

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Clear skies and happy observing!

Whether you're wandering the Bavarian Alps, the Scottish Highlands, or the French countryside, June’s Serpens promises a celestial safari full of contrast — glittering globulars, sculpted nebulae, and colliding galaxies. Take your time to tame it — and share your best photos with the community!