μ Persei (mu Persei)

μ Persei is a variable and multiple hypergiant star in the constellation of Perseus.

μ Persei visual magnitude is 4.14. Because of its moderate brightness, μ Persei should be easily visible from locations with dark skyes, while it can be barely visible, or not visible at all, from skyes affected by light pollution.

The table below summarizes the key facts about μ Persei:

Color of μ Persei ⬤

Magnitude of μ Persei 4.14

Class Hypergiant

VISIBILITY RIGHT NOW μ Persei (mu Persei) is above the horizon from Greenwich, United Kingdom [change]. Altitude: 41°.

Celestial coordinates and finder chart of μ Persei

μ Persei is situated north of the celestial equator, as such, it is more easily visible from the northern hemisphere. Celestial coordinates for the J2000 equinox as well as galactic coordinates of μ Persei are provided in the following table:

Right Ascension J2000 04h 14m 53s

Declination J2000 +48° 24’ 33”

Galactic Longitude 153.94°

Galactic Latitude -1.82°

Constellation Perseus

The simplified sky map below shows the position of μ Persei in the sky:

Simplified finder chart for μ Persei (mu Persei).

Visibility of μ Persei from your location

Location: Greenwich, United Kingdom [change]
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

μ Persei (mu Persei) is circumpolar and transits at 15:35 UTC (altitude: 86.9°)

Digitized Sky Survey image of μ Persei

The image below is a photograph of μ Persei from the Digitized Sky Survey 2 (DSS2 - see the credits section) taken in the red channel. The area of sky represented in the image is 0.5x0.5 degrees (30x30 arcmins). The proper motion of μ Persei is 0.005 arcsec per year in Right Ascension and -0.018 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

DSS2 image of μ Persei. The red arrow shows the motion of μ Persei during the next 10000 years (0.83 arcmin in Right Ascension and -3.00 arcmin in declination);

Distance of μ Persei from the Sun and relative movement

μ Persei is distant 722.84 light years from the Sun and it is moving far from the Sun at the speed of 8 kilometers per second.

Distance (parsec) 221.73 pc

Distance (light year) 722.84 ly

Heliocentric radial velocity 8 km/s

Proper Motion RA 0.005 arcsec/year

Proper Motion Dec -0.018 arcsec/year

Spectral properties of μ Persei

μ Persei belongs to spectral class G0 and has a luminosity class of I corresponding to a hypergiant star.

Absolute magnitude -2.59

Spectral Type G0I

Color Index (B-V) 0.95

Temperature of μ Persei 4866K

The red dot in the diagram below shows where μ Persei is situated in the Hertzsprung–Russell diagram.

H-R diagram showing the position of μ Persei. Attribution: Richard Powell / CC BY-SA

μ Persei star system properties

μ Persei is a visual double star which can be observed only with the help of very large telescopes. The table below shows key information about the μ Persei double sysyem:

Main star magnitude 4.14

Secondary star magnitude 10.14

Magnitude difference 6

Separation 83.8 arcsec

Alternative designations of μ Persei

Bayer designation μ Persei
(mu Persei)

Flamsteed designation 51 Persei

Henry Draper Catalogue HD26630

SAO Catalogue SAO39404

Hipparcos Catalogue HIP19812

Durchmusterung Catalogue BD+48 1063

FK5 Catalogue 1117

General Catalogue of Variable Stars 1518

Aitken Double Star Catalogue ADS3071

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