ο2 Orionis (omicron2 Orionis)

Altitude: 41.8° Azimuth: 231.7° Direction: South-West

ο2 Orionis is a multiple giant star in the constellation of Orion.

ο2 Orionis visual magnitude is 4.07. Because of its moderate brightness, ο2 Orionis 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 ο2 Orionis:

Color of ο2 Orionis ⬤

Magnitude of ο2 Orionis 4.07

Class Giant

VISIBILITY RIGHT NOW

ο2 Orionis (omicron2 Orionis) is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 41.8°
Azimuth: 231.7°
Direction: South-West

Celestial coordinates and finder chart of ο2 Orionis

ο2 Orionis is situated close to the celestial equator, as such, it is at least partly visible from both hemispheres in certain times of the year. Celestial coordinates for the J2000 equinox as well as galactic coordinates of ο2 Orionis are provided in the following table:

Right Ascension J2000 04h 56m 22s

Declination J2000 +13° 30’ 51”

Galactic Longitude 186.63°

Galactic Latitude -18.05°

Constellation Orion

The simplified sky map below shows the position of ο2 Orionis in the sky:

Finder chart ο2 Orionis (omicron2 Orionis) star

Simplified finder chart for ο2 Orionis (omicron2 Orionis).

Visibility of ο2 Orionis from your location

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

Today's ο2 Orionis (omicron2 Orionis) rise, transit and set times from Greenwich, United Kingdom edit_location_alt are the following (all times relative to the local timezone Europe/London):

Azimuth: 76.5° RISE 16:34

Max altitude: 52.0° TRANSIT 23:42

Azimuth: 283.5° SET 6:54

Digitized Sky Survey image of ο2 Orionis

The image below is a photograph of ο2 Orionis 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 ο2 Orionis is -0.074 arcsec per year in Right Ascension and -0.047 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of ο2 Orionis (omicron2 Orionis) star

DSS2 image of ο2 Orionis. The red arrow shows the motion of ο2 Orionis during the next 10000 years (-12.33 arcmin in Right Ascension and -7.83 arcmin in declination);

Distance of ο2 Orionis from the Sun and relative movement

ο2 Orionis is distant 169.26 light years from the Sun and it is moving far from the Sun at the speed of 1 kilometers per second.

Distance (parsec) 51.92 pc

Distance (light year) 169.26 ly

Heliocentric radial velocity 1 km/s

Proper Motion RA -0.074 arcsec/year

Proper Motion Dec -0.047 arcsec/year

Spectral properties of ο2 Orionis

ο2 Orionis belongs to spectral class K2 and has a luminosity class of III corresponding to a giant star.

Absolute magnitude 0.49

Spectral Type K2III

Color Index (B-V) 1.15

Temperature of ο2 Orionis 4409K

The red dot in the diagram below shows where ο2 Orionis is situated in the Hertzsprung–Russell diagram.

H-R diagram showing the position of ο2 Orionis. Attribution: Richard Powell / CC BY-SA

ο2 Orionis star system properties

ο2 Orionis 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 ο2 Orionis double sysyem:

Main star magnitude 4.07

Secondary star magnitude 11.57

Magnitude difference 7.5

Separation 100.4 arcsec

Alternative designations of ο2 Orionis

Bayer designation ο2 Orionis
(omicron2 Orionis)

Flamsteed designation 9 Orionis

Henry Draper Catalogue HD31421

SAO Catalogue SAO94218

Hipparcos Catalogue HIP22957

Durchmusterung Catalogue BD+13 740

Aitken Double Star Catalogue ADS3540

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In Evidence

Other stars in Orion