Your Guide to the Solar System and the Night Sky
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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 4:44  
clear_day Transit: 12:57  
SunsetSet: 21:11 south
wb_twilight Astronomical TwilightWhat's Visible Now
All Constellations » Leo » 

40 Leonis

Altitude: -4.7°   Azimuth: 309.8°   Direction: North-West

40 Leonis is a variable sub-giant star in the constellation of Leo.

40 Leonis visual magnitude is 4.79. Because of its moderate brightness, 40 Leonis 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 40 Leonis:


40 Leonis is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -4.7°
Azimuth: 309.8°
Direction: North-West

Celestial coordinates and finder chart of 40 Leonis

40 Leonis 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 40 Leonis are provided in the following table:

10h 19m 44s
+19° 28’ 14”

The simplified sky map below shows the position of 40 Leonis in the sky:

Finder chart 40 Leonis star
Simplified finder chart for 40 Leonis.

Visibility of 40 Leonis 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 40 Leonis 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: 70.5°
Max altitude: 58.0°
Azimuth: 289.5°
40 Leonis is below the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of 40 Leonis

The image below is a photograph of 40 Leonis 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 40 Leonis is -0.234 arcsec per year in Right Ascension and -0.214 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of 40 Leonis star
DSS2 image of 40 Leonis. The red arrow shows the motion of 40 Leonis during the next 1000 years (-3.90 arcmin in Right Ascension and -3.57 arcmin in declination);

Distance of 40 Leonis from the Sun and relative movement

40 Leonis is distant 69.01 light years from the Sun and it is moving far from the Sun at the speed of 7 kilometers per second.

21.17 pc
69.01 ly
7 km/s
-0.234 arcsec/year
-0.214 arcsec/year

Spectral properties of 40 Leonis

40 Leonis belongs to spectral class F6 and has a luminosity class of IV corresponding to a sub-giant star.


The red dot in the diagram below shows where 40 Leonis is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of 40 Leonis. Attribution: Richard Powell / CC BY-SA

Alternative designations of 40 Leonis

Gl 388.1