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A Complete Guide to the Solar System and the Night Sky
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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 7:41  
clear_day Transit: 11:47  
SunsetSet: 15:53 south
sleep NighttimeWhat's Visible Now?
All Constellations » Leo » 

81 Leonis

Altitude: 45.1°   Azimuth: 128.1°   Direction: South-East

81 Leonis is a double main-sequence star in the constellation of Leo.

81 Leonis visual magnitude is 5.57. Because of its reltive faintness, 81 Leonis should be visible only from locations with dark skyes, while it is not visible at all from skyes affected by light pollution.

The table below summarizes the key facts about 81 Leonis:

5.57
Main-sequence

81 Leonis is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 45.1°
Azimuth: 128.1°
Direction: South-East

Celestial coordinates and finder chart of 81 Leonis

81 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 81 Leonis are provided in the following table:

11h 25m 36s
+16° 27’ 23”
236.75°
67.45°
Leo

The simplified sky map below shows the position of 81 Leonis in the sky:

Finder chart 81 Leonis star
Simplified finder chart for 81 Leonis.

Visibility of 81 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 81 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: 73.5°
Max altitude: 55.0°
Azimuth: 286.5°

Digitized Sky Survey image of 81 Leonis

The image below is a photograph of 81 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 81 Leonis is -0.143 arcsec per year in Right Ascension and -0.005 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of 81 Leonis star
DSS2 image of 81 Leonis. The red arrow shows the motion of 81 Leonis during the next 1000 years (-2.38 arcmin in Right Ascension and -0.08 arcmin in declination);

Distance of 81 Leonis from the Sun and relative movement

81 Leonis is distant 154.14 light years from the Sun and it is moving far from the Sun at the speed of 18 kilometers per second.

47.28 pc
154.14 ly
18 km/s
-0.143 arcsec/year
-0.005 arcsec/year

Spectral properties of 81 Leonis

81 Leonis belongs to spectral class F2 and has a luminosity class of V corresponding to a main-sequence star.

2.20
F2V
7101K

The red dot in the diagram below shows where 81 Leonis is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of 81 Leonis. Attribution: Richard Powell / CC BY-SA

81 Leonis star system properties

81 Leonis is a visual double star which can be observed with binoculars or small telescopes. The table below shows key information about the 81 Leonis double sysyem:

5.57
9.17
3.6
55.7 arcsec

Alternative designations of 81 Leonis

SAO99601
SAO99601