NGC 1528 — Open Cluster in Perseus
About NGC 1528
Description
NGC 1528 is a bright, moderately rich open cluster in Perseus, about 2,500 light-years away. At magnitude 6.4 it sits just on the threshold of naked-eye visibility from a dark site, and in binoculars it displays perhaps 40 to 60 stars scattered across 24 arcminutes — roughly the width of the full Moon. The cluster lies in a rich Milky Way field between the famous Perseus OB2 association and the Double Cluster, and it pairs naturally with its fainter neighbor NGC 1545, which lies less than a degree to the south-southwest. Both clusters are young (~300 million years) and share the general population of hot B-type stars typical of Perseus.
Observing Tips
A fine binocular and small-telescope target. In 10x50 binoculars it appears as a small resolved clump of perhaps a dozen bright stars set in a hazy background. A 4-inch telescope at 40-60x is ideal: the cluster fills the field with 50+ stars arranged in several loose chains and clumps with distinct darker lanes crossing it. Pair the view with NGC 1545 to the south for a nice double-cluster session separate from the more famous NGC 869/884 pair. Best observed from October through March when Perseus is high in the evening sky.
History
Discovered by William Herschel on December 28, 1790. Herschel described it as 'a beautiful cluster of large stars,' noting it was easily resolved. It appears in most 19th and 20th century observing guides as a secondary Perseus target eclipsed by the fame of the nearby Double Cluster. Modern studies have refined its distance and age, confirming its membership in the young population of stars filling the Perseus arm of the Milky Way.
Fun Facts
NGC 1528 is one of several very nice Perseus clusters that get overlooked because the Double Cluster is so nearby and so spectacular. Observers who take the time to sweep the full Perseus Milky Way often come away surprised at how rich the region is beyond the famous pair. The cluster is slowly dispersing; in about another 100 million years its member stars will have drifted far enough apart that it will no longer look like a cluster at all.
Observe
1Properties
Position & Identifiers
2How easy to spot?
| Telescope | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| 80 mm refractor 80mm refr. | Easy | Easy | Easy |
| 150 mm Newton 150mm Newt. | Easy | Easy | Easy |
| Celestron C8 (203 mm SCT) C8 203mm | Easy | Easy | Easy |
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
3Visibility
Set a location in User Settings to see visibility data.
4
Eyepiece View
5
Best Magnification
6Where this cluster sits in time
Open clusters span more than four orders of magnitude in age — from newborn OB associations to ancient, metal-rich survivors.
7
Colour-Magnitude Diagram
A cluster's colour-magnitude diagram reveals its age: the bluer the turn-off point where the main sequence bends into red giants, the younger the cluster.
Each point is a Gaia-DR3 member. Colour encodes spectral type; size reflects membership probability.
Explore
8
Classification Decoder
Nearby in the Sky
Other targets within a few degrees — pan your scope a little and keep exploring.
Visibility scores assume a 150 mm Newton at Bortle 4.
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