ο Cassiopeiae (omicron Cassiopeiae)

ο Cassiopeiae is a variable and double giant star in the constellation of Cassiopeia.

ο Cassiopeiae visual magnitude is 4.54. Because of its moderate brightness, ο Cassiopeiae 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 ο Cassiopeiae:

Color of ο Cassiopeiae ⬤

Magnitude of ο Cassiopeiae 4.54

Class Giant

VISIBILITY RIGHT NOW ο Cassiopeiae (omicron Cassiopeiae) is above the horizon from Greenwich, United Kingdom [change]. Altitude: 28°.

Celestial coordinates and finder chart of ο Cassiopeiae

ο Cassiopeiae 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 ο Cassiopeiae are provided in the following table:

Right Ascension J2000 00h 44m 43s

Declination J2000 +48° 17’ 03”

Galactic Longitude 121.78°

Galactic Latitude -14.57°

Constellation Cassiopeia

The simplified sky map below shows the position of ο Cassiopeiae in the sky:

Finder chart ο Cassiopeiae (omicron Cassiopeiae) star

Simplified finder chart for ο Cassiopeiae (omicron Cassiopeiae).

Visibility of ο Cassiopeiae from your location

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

ο Cassiopeiae (omicron Cassiopeiae) is circumpolar and transits at 12:22 UTC (altitude: 86.8°)

Digitized Sky Survey image of ο Cassiopeiae

The image below is a photograph of ο Cassiopeiae 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 ο Cassiopeiae is 0.019 arcsec per year in Right Ascension and -0.008 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of ο Cassiopeiae (omicron Cassiopeiae) star

DSS2 image of ο Cassiopeiae. The red arrow shows the motion of ο Cassiopeiae during the next 10000 years (3.17 arcmin in Right Ascension and -1.33 arcmin in declination);

Distance of ο Cassiopeiae from the Sun and relative movement

ο Cassiopeiae is distant 905.56 light years from the Sun and it is moving towards the Sun at the speed of 17 kilometers per second.

Distance (parsec) 277.78 pc

Distance (light year) 905.56 ly

Heliocentric radial velocity -17 km/s

Proper Motion RA 0.019 arcsec/year

Proper Motion Dec -0.008 arcsec/year

Spectral properties of ο Cassiopeiae

ο Cassiopeiae belongs to spectral class B5 and has a luminosity class of III corresponding to a giant star.

Absolute magnitude -2.68

Spectral Type B5III

Color Index (B-V) -0.07

Temperature of ο Cassiopeiae 11092K

The red dot in the diagram below shows where ο Cassiopeiae is situated in the Hertzsprung–Russell diagram.

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

ο Cassiopeiae star system properties

ο Cassiopeiae 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 ο Cassiopeiae double sysyem:

Main star magnitude 4.54

Secondary star magnitude 11.74

Magnitude difference 7.2

Separation 33.6 arcsec

Alternative designations of ο Cassiopeiae

Bayer designation ο Cassiopeiae
(omicron Cassiopeiae)

Flamsteed designation 22 Cassiopeiae

Henry Draper Catalogue HD4180

SAO Catalogue SAO36620

Hipparcos Catalogue HIP3504

Durchmusterung Catalogue BD+47 183

FK5 Catalogue 25

General Catalogue of Variable Stars Omi Cas

Aitken Double Star Catalogue ADS622

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Other stars in Cassiopeia