Week 15 · Deep Sky & Planetary Targets

The Pleiades: The Best Binocular Target in the Night Sky

Most beginners assume bigger kit always equals better view. The Pleiades cluster is the magnificent counter-example. It looks better in a £40 pair of binoculars than in a £400 telescope.

Beginner · 6 min read

This is one of those gentle truths the hobby teaches you over time. Bigger telescopes are not always better telescopes. Some objects need wide field of view more than they need magnification, and the Pleiades is the perfect example.

Through a beginner Dobsonian at 50x, you see four or five bright stars filling the entire eyepiece. Through 10x50 binoculars, you see all seven main stars plus dozens of fainter ones, all framed against the dark sky in a single graceful sweep. The binocular view is genuinely more beautiful.

What the Pleiades is

The Pleiades (also called M45 or the Seven Sisters) is an open cluster of around 1,000 stars, of which about seven are bright enough to see with the bare eye. They are about 444 light years away, which makes them one of the closest clusters to Earth, and they are gravitationally bound, so they were all born together about 100 million years ago from the same gas cloud.

That cloud is mostly gone now, but bits of it still surround the brightest stars. On long-exposure photos you can see beautiful blue nebulosity wrapped around the cluster. With your eye through any telescope, the nebulosity is too faint to see, but the cluster itself is gorgeous.

How to find it

Trivially easy from October to March. With the bare eye, look for what appears to be a tiny, fuzzy, blue-tinged smudge in the constellation Taurus. Most people see it and think "that's a smudge of mist on a star, isn't it?" Then they look more carefully and realise it is a tight little cluster of stars.

  1. Find Orion's Belt (south on a winter evening).
  2. Follow the line of the Belt up and to the right.
  3. You'll pass a bright orange star. That is Aldebaran, the eye of Taurus the Bull.
  4. Keep going past Aldebaran in the same direction. You will arrive at a tight little smudge of stars. That is the Pleiades.

Look at the smudge with binoculars and the magic happens. Five, six, seven, then twenty stars resolve out of the fuzz, all close together, all blue-white, all sharp.

Why binoculars beat telescopes here

The Pleiades is about 2 degrees across in the sky. That is four times the diameter of the full Moon. A typical beginner telescope shows you about 1 degree of sky in a wide-field eyepiece. So at the lowest possible magnification through a telescope, you cannot even fit the whole cluster in one view. You see a few of the bright stars and the rest hang out of frame.

10x50 binoculars show about 5 degrees of sky. The Pleiades sits comfortably in the middle with plenty of dark sky around it for context. You see the cluster as a whole. You see how it sits among the surrounding fainter stars. You see its shape. The view is composed in a way the telescope cannot manage.

This is not a weakness of telescopes. It is what telescopes are for: high-magnification work on small targets. It is just that the Pleiades is a wide-field target.

The "more stars" trick

Hold the binoculars up to your eyes, point them at the Pleiades, and just stop and stare for a minute. Stars resolve gradually as your eyes dark-adapt. The first glance shows seven main stars. After thirty seconds you see fifteen or twenty. After a minute, dozens. The cluster keeps revealing more stars the longer you look.

This is partly your eyes adjusting and partly your brain processing the faint pinpoints. Either way, do not move on after a glance. The Pleiades rewards patience.

Why it looks blue

The seven brightest stars in the Pleiades are hot, young, type-B stars. Their surface temperature is around 12,000-15,000 degrees, much hotter than our Sun (5,500 degrees). Hot stars emit light at the blue end of the spectrum.

You can clearly see the blue tint with your bare eyes if you look carefully, especially against the orange of Aldebaran nearby. In binoculars the blue is gorgeous and obvious. In a telescope it is still there but the cluster is broken up so the colour-against-cluster effect is less striking.

Other binocular-friendly clusters

If the Pleiades hooks you, here are four more clusters that look better in binoculars than in beginner telescopes:

All of them are too big for a typical telescope eyepiece. All of them sit beautifully in 10x50 binoculars. All of them are easy to find with a star chart app.

The grown-up trick. Get binoculars, a deck chair and a hot drink. Sit back so the binoculars rest on your forehead and your elbows on the chair arms. You can scan the Milky Way for hours without arms getting tired. This is genuinely how a lot of experienced observers spend their best evenings, no telescope at all.

Photographing the Pleiades

The Pleiades is one of the few deep-sky targets where you can get a good phone photograph without a tracking mount. Stick your phone on a tripod, use night mode if your phone has it, take a 5-10 second exposure pointed roughly at the cluster, and you will capture all seven bright stars and a hint of the surrounding faint ones. With practice you can get a recognisable Pleiades image in one or two attempts.

To capture the famous blue nebulosity around the stars you need a tracking mount and longer exposures (minutes, not seconds). That is a step beyond beginner kit, but the bare cluster is very achievable with what you have.

The bigger lesson

The Pleiades teaches a lesson that takes most astronomers a year or two to fully internalise: the right tool depends on the target. Telescopes win for planets and small bright nebulae. Binoculars win for wide clusters and Milky Way sweeping. Naked-eye observing wins for constellation patterns, meteor showers and aurora. None of them is "better" overall.

The most well-equipped observers have all three: a scope, a pair of binoculars and a comfortable chair to lie back in. They use whichever fits the night and the target.

Editor's pick

For the best possible view of the Pleiades and the dozens of other binocular-favourite targets across the year, a pair of Wide-angle Binoculars with a 6+ degree field of view will give you frame-filling cluster views that no beginner telescope can match. 10x50 with wide-angle eyepieces hits the sweet spot for hand-held use.