The Pleiades or Seven Sisters form a magnificent star cluster near the constellation Taurus. It is one of the closest star clusters to Earth and perhaps the most attractive to the naked eye. Over the millennia, it has inspired folklore around the world and is today studied as a recent birthplace of new stars.
Method 1 of 2: In the northern hemisphere
Step 1. Look for fall and winter
In the northern hemisphere, the Pleiades become visible to night watchers in October and disappear in April. November is the best time to see them, when they are visible from dusk to dawn and reach their highest point in the sky.
- At the beginning of October, the Pleiades become visible a few hours after sunset. Around February, they are already very high in the sky at sunset. (The exact time will depend on your latitude.)
- The Pleiades are also visible in late summer and early fall, but only in the middle of the night.
Step 2. Look at the southern part of the sky
The Pleiades rise in the southeast after dusk and move west at night. At their peak in November, they soar high in the sky and disappear in the northwest before dawn. In late winter and early spring, they are only visible for a few hours, moving from east to west in the southern part of the sky.
Step 3. Search for Orion
Orion the hunter is one of the most famous and distinctive constellations in the sky. On winter evenings at mid-northern latitude, it lies almost due south, roughly halfway between the horizon and the sky directly above your head. Locate it using its belt, a straight line of three bright stars close together. The neighboring red star, Betelgeuse, forms his left shoulder (from your perspective), while the blue giant Rigel, on the other side of the belt, is his right leg.
Step 4. Follow the belt line to Aldebaran
Think of Orion's belt as an arrow going left to right across the sky and pointing to your next landmark. (The next bright star you'll see in that direction is another bright, red-orange star: Aldebaran. It's an Arabic word meaning "follower," probably named so because it pursues the Pleiades every night.)
- Aldebaran is not aligned perfectly with the belt. Don't try to spot it with binoculars or you might miss it.
- Aldebaran descends below the horizon around March or earlier in the extreme northern latitudes. If you can't see it, try following the Orion belt to the Pleiades.
Step 5. Keep looking for the Pleiades
Move your eyes in the same direction (usually northwest), from the Orion belt to Aldebaran and beyond. Next to Aldebaran, you should see a compact cluster of blue stars. These are the Pleiades, also called the Seven Sisters or M45.
- Most people can only see 6 stars with the naked eye or even just a hazy cluster if there is too much light pollution. On a clear night and with keen, dark-adapted eyes, you can see more than seven.
- The seven sisters are grouped very close to each other. Throughout, the cluster is only ⅔ the width of Orion's belt. This is much less than the length of the Big Dipper or the Little Dipper, stars that some novice astrologers confuse with the Pleiades.
Step 6. Use Taurus as a guide
The red star Aldebaran, described above, is also the eye of the constellation Taurus. The nearby Hyades star cluster forms the chin of the bull. If you are familiar with this constellation, you can take it as a starting point and look for the Pleiades nearby.
Taurus may be difficult to see with a bright moon, especially near an urban area
Method 2 of 2: In the southern hemisphere
Step 1. Look for the Pleiades in spring and summer
The Pleiades are visible from October to April, during the spring and summer months in the southern hemisphere.
Step 2. Look north
In late November, the Pleiades rise northeast towards dusk and move west until dawn. Over the seasons, they move higher when the stars appear and spend less time in the sky.
Step 3. Look for a line of bright stars
In the southern hemisphere, Orion stands on his head, which is why some observers call this constellation more of a saucepan, with Orion's sword with the hilt facing up. The edge of the pan (or Orion's belt) is a trio of bright stars aligned in a straight line. This distinct shape is the starting point for locating many constellations.
This line includes the bright red star Betelgeuse on one side and the blue star Rigel on the other
Step 4. Follow the line to the left to Aldebaran
Use this line as an arrow pointing left in the sky. The next bright star in that direction is Aldebaran, a bright red supergiant. It is the eye of the constellation Taurus. If the sky is clear and the Moon is not too bright, you can see the chin of the bull formed by the Hyades star cluster, right next to Aldebaran.
Step 5. Continue to the Pleiades
Follow the same line from Orion's belt and you'll come across a faint cluster of blue stars. These are the Pleiades, also known as the Seven Sisters, although most people can only see six or less and telescopes see many more. The Pleiades are an "asterism", a set of stars much smaller than a constellation. If you stretch out your thumb at arm's length, the cluster is only twice the width of your fingernail.
- Use binoculars rather than a telescope. The Pleiades cover a relatively large area, and binoculars have a wider field of view than a telescope.
- When the Pleiades disappear, they continue to rise above the horizon, but too close to the Dawn Sun to be visible. Around May or June it is possible to see them at dawn, but it will be difficult and the sky must be clear. The first “heliacal lever” (rising near the Sun) of the year is linked to summer festivals in some regions.