How to find Perseus
The hero of autumn, home to the Double Cluster, the 'Demon Star' Algol, and the Perseid radiant.
Mirfak — set in a loose, pretty star cluster.
Perseus rides the autumn and early-winter Milky Way between Cassiopeia and Auriga. It's rich in star clusters and contains Algol, the original 'eclipsing' variable star whose brightness visibly dips every few days.
It's also the radiant of the Perseids, the popular August meteor shower.
Algol, the Demon Star
Algol is a pair of stars that orbit so that one periodically eclipses the other, dimming the star noticeably every 2.87 days. Ancient observers, unsettled by a star that 'winked', named it the Demon Star.
The Double Cluster
Between Perseus and Cassiopeia lies the Double Cluster (NGC 869 and 884) — two rich open clusters side by side, visible to the naked eye from a dark site and gorgeous in binoculars.
How to find it
- Find Cassiopeia's 'W', then look toward Auriga's bright Capella — Perseus lies between them
- Mirfak sits in a loose scattering of stars in the Milky Way
- The Double Cluster is the misty patch between Perseus and Cassiopeia
Deep-sky highlights
- Double Cluster (NGC 869 & 884) — twin naked-eye open clusters
- Open cluster M34
- Algol — a naked-eye eclipsing variable
Stella shows exactly when Perseus is highest from your location tonight — and whether the sky is worth it.
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