Magnitude 6.35 | ||
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5 Persei is a blue supergiant star in the constellation Perseus located around 2,950 parsecs (9,600 ly) away. It is part of the Perseus OB1 stellar association and lies near the Double Cluster.
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Companions
5 Persei has two close companions, a 12th magnitude star 5.7 arc-seconds away and a 13th magnitude star one arc-minute away.
Variability
Several studies of 5 Persei have detected possible small amplitude variations. In 1983, an amplitude of 0.045 magnitudes was measured with a possible period of eight days. An analysis of Hipparcos photometry showed an amplitude of 0.0168 magnitudes and a period of 2.65 days. The statistical signal was strong enough for the variability to be very likely, but 5 Persei has not formally been catalogued as a variable star.
Properties
The primary, with an apparent magnitude of 6.27, is a blue supergiant of spectral type B5 Ia, a massive star that has used up its core hydrogen and expanded into a very luminous star. It has a temperature around 15,000 K.