23 Ursae Majoris

23 Ursae Majoris is a variable and multiple hypergiant star in the constellation of Ursa Major.

23 Ursae Majoris visual magnitude is 3.67. Because of its moderate brightness, 23 Ursae Majoris 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 23 Ursae Majoris:

Color of 23 Ursae Majoris ⬤

Magnitude of 23 Ursae Majoris 3.67

Class Hypergiant

VISIBILITY RIGHT NOW 23 Ursae Majoris is above the horizon from Greenwich, United Kingdom edit_location_alt. Altitude: 48°.

Celestial coordinates and finder chart of 23 Ursae Majoris

23 Ursae Majoris is situated close to the northern celestial pole and, as such, it is visible for most part of the year from the northern hemisphere. Celestial coordinates for the J2000 equinox as well as galactic coordinates of 23 Ursae Majoris are provided in the following table:

Right Ascension J2000 09h 31m 31s

Declination J2000 +63° 03’ 42”

Galactic Longitude 150.64°

Galactic Latitude 41.74°

Constellation Ursa Major

The simplified sky map below shows the position of 23 Ursae Majoris in the sky:

Simplified finder chart for 23 Ursae Majoris.

Visibility of 23 Ursae Majoris from your location

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

23 Ursae Majoris is circumpolar and transits at 17:03 UTC (altitude: 78.4°)

Digitized Sky Survey image of 23 Ursae Majoris

The image below is a photograph of 23 Ursae Majoris 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 23 Ursae Majoris is 0.109 arcsec per year in Right Ascension and 0.028 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

DSS2 image of 23 Ursae Majoris. The red arrow shows the motion of 23 Ursae Majoris during the next 1000 years (1.82 arcmin in Right Ascension and 0.47 arcmin in declination);

Distance of 23 Ursae Majoris from the Sun and relative movement

23 Ursae Majoris is distant 75.46 light years from the Sun and it is moving towards the Sun at the speed of 10 kilometers per second.

Distance (parsec) 23.15 pc

Distance (light year) 75.46 ly

Heliocentric radial velocity -10 km/s

Proper Motion RA 0.109 arcsec/year

Proper Motion Dec 0.028 arcsec/year

Spectral properties of 23 Ursae Majoris

23 Ursae Majoris belongs to spectral class F0 and has a luminosity class of IV corresponding to a hypergiant star.

Absolute magnitude 1.85

Spectral Type F0IV

Color Index (B-V) 0.33

Temperature of 23 Ursae Majoris 7276K

The red dot in the diagram below shows where 23 Ursae Majoris is situated in the Hertzsprung–Russell diagram.

H-R diagram showing the position of 23 Ursae Majoris. Attribution: Richard Powell / CC BY-SA

23 Ursae Majoris star system properties

23 Ursae Majoris 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 23 Ursae Majoris double sysyem:

Main star magnitude 3.67

Secondary star magnitude 9.27

Magnitude difference 5.6

Separation 22.8 arcsec

Alternative designations of 23 Ursae Majoris

Flamsteed designation 23 Ursae Majoris

Henry Draper Catalogue HD81937

SAO Catalogue SAO14908

Hipparcos Catalogue HIP46733

Durchmusterung Catalogue BD+63 845

Gliese Catalogue NN 3559

FK5 Catalogue 355

General Catalogue of Variable Stars 4506

Aitken Double Star Catalogue ADS7402

In Evidence

Other stars in Ursa Major