ε Persei (epsilon Persei)

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

ε Persei visual magnitude is 2.89. Thanks to its high brightness, ε Persei is clearly visible when observed from locations with dark skyes, and should be also quite easily visible from light polluted areas.

The table below summarizes the key facts about ε Persei:

Color of ε Persei ⬤

Magnitude of ε Persei 2.89

Class Hypergiant

VISIBILITY RIGHT NOW ε Persei (epsilon Persei) is above the horizon from Greenwich, United Kingdom [change]. Altitude: 54°.

Celestial coordinates and finder chart of ε Persei

ε 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 ε Persei are provided in the following table:

Right Ascension J2000 03h 57m 51s

Declination J2000 +40° 00’ 37”

Galactic Longitude 157.35°

Galactic Latitude -10.09°

Constellation Perseus

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

Finder chart ε Persei (epsilon Persei) star

Simplified finder chart for ε Persei (epsilon Persei).

Visibility of ε Persei from your location

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

ε Persei (epsilon Persei) is circumpolar and transits at 15:50 UTC (altitude: 78.5°)

Digitized Sky Survey image of ε Persei

The image below is a photograph of ε 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 ε Persei is 0.018 arcsec per year in Right Ascension and -0.026 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

DSS2 image of ε Persei. The red arrow shows the motion of ε Persei during the next 10000 years (3.00 arcmin in Right Ascension and -4.33 arcmin in declination);

Distance of ε Persei from the Sun and relative movement

ε Persei is distant 537.95 light years from the Sun and it is moving far from the Sun at the speed of 1 kilometers per second.

Distance (parsec) 165.02 pc

Distance (light year) 537.95 ly

Heliocentric radial velocity 1 km/s

Proper Motion RA 0.018 arcsec/year

Proper Motion Dec -0.026 arcsec/year

Spectral properties of ε Persei

ε Persei belongs to spectral class B0 and has a luminosity class of V corresponding to a hypergiant star.

Absolute magnitude -3.20

Spectral Type B0V

Color Index (B-V) -0.18

Temperature of ε Persei 13121K

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

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

ε Persei star system properties

ε Persei is a visual double star which can be observed with the help of small or medium telescopes. The table below shows key information about the ε Persei double sysyem:

Main star magnitude 2.89

Secondary star magnitude 7.99

Magnitude difference 5.1

Separation 8.8 arcsec

Alternative designations of ε Persei

Bayer designation ε Persei
(epsilon Persei)

Flamsteed designation 45 Persei

Henry Draper Catalogue HD24760

SAO Catalogue SAO56840

Hipparcos Catalogue HIP18532

Durchmusterung Catalogue BD+39 895

FK5 Catalogue 147

General Catalogue of Variable Stars Eps Per

Aitken Double Star Catalogue ADS2888

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