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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
SunriseRise: 6:40  
clear_day Transit: 12:10  
SunsetSet: 17:41
sunny DaytimeWhat's Visible Now?
All Constellations » Aquarius » 

81 Aquarii

Altitude: 27.6°   Azimuth: 208.3°   Direction: South-South-West

81 Aquarii is a giant star in the constellation of Aquarius.

81 Aquarii visual magnitude is 6.21. Because of its reltive faintness, 81 Aquarii should be visible only from locations with dark skies, while it is not visible at all from skies affected by light pollution.

The proper motion of 81 Aquarii is -0.015 arcsec per year in Right Ascension and -0.011 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of 81 Aquarii star
DSS2 image of 81 Aquarii. The red arrow shows the motion of 81 Aquarii during the next 10000 years (-2.50 arcmin in Right Ascension and -1.83 arcmin in declination);

Key facts about 81 Aquarii

6.21
Giant

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

Altitude: 27.6°
Azimuth: 208.3°
Direction: South-South-West

Celestial coordinates and finder chart of 81 Aquarii

81 Aquarii 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 Aquarii are provided in the following table:

23h 01m 23s
-07° 03’ 39”
65.42°
-57.08°
Aquarius

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

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

Visibility of 81 Aquarii 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 Aquarii 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: 97.1°
Max altitude: 31.5°
Azimuth: 262.9°

Distance of 81 Aquarii from the Sun and relative movement

81 Aquarii is distant 418.49 light years from the Sun and it is moving towards the Sun at the speed of 2 kilometers per second.

128.37 pc
418.49 ly
-2 km/s
-0.015 arcsec/year
-0.011 arcsec/year

Spectral properties of 81 Aquarii

81 Aquarii belongs to spectral class K5 and has a luminosity class of III corresponding to a giant star.

0.67
K5III
3934K

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

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

Alternative designations of 81 Aquarii

SAO146447
SAO146447