Perseus
A curving chain of stars between Cassiopeia and the Pleiades, marking the hero who rescued Andromeda in the Greek myth. Perseus holds one of the sky's finest binocular sights: the Double Cluster.
Star chart · schematic positions
Drag to pan · dashed rings mark deep-sky objects · east is left
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Tap any labelled star in the chart to read its name, magnitude and spectral type.
Why it matters
Perseus contains Algol, the Demon Star — an eclipsing binary that dims visibly every 2.87 days, one of the first variable stars ever recorded. The constellation also hosts the Double Cluster, two open clusters that look spectacular together in binoculars, and is the radiant of the August Perseid meteor shower.
How to find it tonight
- 1Find Cassiopeia, then follow its eastern arm down towards a curving chain of stars — that is Perseus.
- 2Mirfak is the brightest of the chain, with a loose scattering of stars around it.
- 3Algol lies south of the chain and is noticeably dimmer every few nights — compare it with nearby stars.
- 4Look between Perseus and Cassiopeia for the Double Cluster: two fuzzy knots of stars close together in binoculars.
Brightest stars on the chart
Mirfak (α Persei) · Algol (β Persei) · Zeta Persei (ζ Persei) · Epsilon Persei (ε Persei)
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Figures are rounded averages from NASA, ESA and IAU reference data. Star positions on charts are schematic and approximate.