We use cookies to deliver essential features and to measure their performance. By using this site you accept our Privacy Policies.
A Complete Guide to the Solar System and the Night Sky
Your support helps us pay the server bills » Donate
public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
SunriseRise: 6:46  
clear_day Transit: 12:11  
SunsetSet: 17:36
wb_twilight Civil TwilightWhat's Visible Now?
All Constellations » Orion » 

31 Orionis

Altitude: 36.6°   Azimuth: 166.5°   Direction: South-South-East

31 Orionis is a variable and double giant star in the constellation of Orion.

31 Orionis visual magnitude is 4.71. Because of its moderate brightness, 31 Orionis should be easily visible from locations with dark skies, while it can be barely visible, or not visible at all, from skies affected by light pollution.

The proper motion of 31 Orionis is 0.004 arcsec per year in Right Ascension and -0.023 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of 31 Orionis star
DSS2 image of 31 Orionis. The red arrow shows the motion of 31 Orionis during the next 10000 years (0.67 arcmin in Right Ascension and -3.83 arcmin in declination);

Key facts about 31 Orionis

4.71
Giant

31 Orionis is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 36.6°
Azimuth: 166.5°
Direction: South-South-East

Celestial coordinates and finder chart of 31 Orionis

31 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 31 Orionis are provided in the following table:

05h 29m 44s
-01° 05’ 31”
204.31°
-18.62°
Orion

The simplified sky map below shows the position of 31 Orionis in the sky:

Finder chart 31 Orionis star
Simplified finder chart for 31 Orionis.

Visibility of 31 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 31 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: 91.1°
Max altitude: 37.4°
Azimuth: 268.9°

Distance of 31 Orionis from the Sun and relative movement

31 Orionis is distant 455.94 light years from the Sun and it is moving far from the Sun at the speed of 8 kilometers per second.

139.86 pc
455.94 ly
8 km/s
0.004 arcsec/year
-0.023 arcsec/year

Spectral properties of 31 Orionis

31 Orionis belongs to spectral class K5 and has a luminosity class of III corresponding to a giant star.

-1.02
K5III
3691K

The red dot in the diagram below shows where 31 Orionis is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of 31 Orionis. Attribution: Richard Powell / CC BY-SA

31 Orionis star system properties

31 Orionis 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 31 Orionis double sysyem:

4.71
10.11
5.4
12.5 arcsec

Alternative designations of 31 Orionis

SAO132176
SAO132176