μ Orionis (mu Orionis)

μ Orionis is a variable and multiple main-sequence star in the constellation of Orion.

μ Orionis visual magnitude is 4.12. Because of its moderate brightness, μ 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 μ Orionis:

Color of μ Orionis ⬤

Magnitude of μ Orionis 4.12

Class Main-sequence

VISIBILITY RIGHT NOW μ Orionis (mu Orionis) is above the horizon from Greenwich, United Kingdom [change]. Altitude: 30°.

Celestial coordinates and finder chart of μ Orionis

μ 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 μ Orionis are provided in the following table:

Right Ascension J2000 06h 02m 22s

Declination J2000 +09° 38’ 51”

Galactic Longitude 198.68°

Galactic Latitude -6.31°

Constellation Orion

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

Finder chart μ Orionis (mu Orionis) star

Simplified finder chart for μ Orionis (mu Orionis).

Visibility of μ Orionis from your location

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

Today's μ Orionis (mu Orionis) rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 80.4° RISE 11:36

Max altitude: 48.2° TRANSIT 18:23

Azimuth: 279.6° SET 1:14

RIGHT NOW μ Orionis (mu Orionis) is above the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of μ Orionis

The image below is a photograph of μ 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 μ Orionis is 0.015 arcsec per year in Right Ascension and -0.028 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

DSS2 image of μ Orionis. The red arrow shows the motion of μ Orionis during the next 10000 years (2.50 arcmin in Right Ascension and -4.67 arcmin in declination);

Distance of μ Orionis from the Sun and relative movement

μ Orionis is distant 151.70 light years from the Sun and it is moving far from the Sun at the speed of 45 kilometers per second.

Distance (parsec) 46.53 pc

Distance (light year) 151.70 ly

Heliocentric radial velocity 45 km/s

Proper Motion RA 0.015 arcsec/year

Proper Motion Dec -0.028 arcsec/year

Spectral properties of μ Orionis

μ Orionis belongs to spectral class A2 and has a luminosity class of V corresponding to a main-sequence star.

Absolute magnitude 0.78

Spectral Type A2V

Color Index (B-V) 0.16

Temperature of μ Orionis 8486K

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

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

μ Orionis star system properties

μ 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 μ Orionis double sysyem:

Main star magnitude 4.12

Secondary star magnitude 5.92

Magnitude difference 1.8

Separation 0.3 arcsec

Alternative designations of μ Orionis

Bayer designation μ Orionis
(mu Orionis)

Flamsteed designation 61 Orionis

Henry Draper Catalogue HD40932

SAO Catalogue SAO113389

Hipparcos Catalogue HIP28614

Durchmusterung Catalogue BD+09 1064

General Catalogue of Variable Stars 2792

Aitken Double Star Catalogue ADS4617

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Other stars in Orion