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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: 7:47  
clear_day Transit: 11:49  
SunsetSet: 15:50 south
wb_twilight Astronomical TwilightWhat's Visible Now?
All Constellations » Apus » 


Altitude: -52.9°   Azimuth: 166.3°   Direction: South-South-East

HR6646 is a giant star in the constellation of Apus.

HR6646 visual magnitude is 6.35. Because of its reltive faintness, HR6646 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 HR6646:


HR6646 is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -52.9°
Azimuth: 166.3°
Direction: South-South-East

Celestial coordinates and finder chart of HR6646

HR6646 is situated close to the southern celestial pole and, as such, it is easilty visible for most part of the year from the southern hemisphere. Celestial coordinates for the J2000 equinox as well as galactic coordinates of HR6646 are provided in the following table:

18h 05m 26s
-81° 29’ 11”

The simplified sky map below shows the position of HR6646 in the sky:

Finder chart HR6646 star
Simplified finder chart for HR6646.

Visibility of HR6646 from your location

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

HR6646 is currently not visible from Greenwich, United Kingdom edit_location_alt

Digitized Sky Survey image of HR6646

The image below is a photograph of HR6646 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 HR6646 is 0.018 arcsec per year in Right Ascension and -0.04 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of HR6646 star
DSS2 image of HR6646. The red arrow shows the motion of HR6646 during the next 10000 years (3.00 arcmin in Right Ascension and -6.67 arcmin in declination);

Distance of HR6646 from the Sun and relative movement

HR6646 is distant 923.51 light years from the Sun and it is moving towards the Sun at the speed of 3 kilometers per second.

283.29 pc
923.51 ly
-3 km/s
0.018 arcsec/year
-0.04 arcsec/year

Spectral properties of HR6646

HR6646 belongs to spectral class K3 and has a luminosity class of III corresponding to a giant star.


The red dot in the diagram below shows where HR6646 is situated in the HertzsprungÔÇôRussell diagram.

HR Diagram
H-R diagram showing the position of HR6646. Attribution: Richard Powell / CC BY-SA

Alternative designations of HR6646