Your Guide to the Solar System and the Night Sky
This site is free and ad-free thanks to the support of our users. If you can, please consider a donation.
public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 6:55  
clear_day Transit: 12:49  
SunsetSet: 18:41 south
sleep NighttimeWhat's Visible Now
All Constellations » Cygnus » 


Altitude: 50.8°   Azimuth: 300.3°   Direction: West-North-West

HR7791 is a multiple giant star in the constellation of Cygnus.

HR7791 visual magnitude is 6.18. Because of its reltive faintness, HR7791 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 HR7791:


HR7791 is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 50.8°
Azimuth: 300.3°
Direction: West-North-West

Celestial coordinates and finder chart of HR7791

HR7791 is situated north of the celestial equator, as such, it is more easily visible from the northern hemisphere. Celestial coordinates for the J2000 equinox as well as galactic coordinates of HR7791 are provided in the following table:

20h 20m 30s
+53° 35’ 45”

The simplified sky map below shows the position of HR7791 in the sky:

Finder chart HR7791 star
Simplified finder chart for HR7791.

Visibility of HR7791 from your location

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

HR7791 is circumpolar and transits at 19:47 UTC (altitude: 87.9°)

Digitized Sky Survey image of HR7791

The image below is a photograph of HR7791 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 HR7791 is -0.016 arcsec per year in Right Ascension and 0.014 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of HR7791 star
DSS2 image of HR7791. The red arrow shows the motion of HR7791 during the next 10000 years (-2.67 arcmin in Right Ascension and 2.33 arcmin in declination);

Distance of HR7791 from the Sun and relative movement

HR7791 is distant 1,630.00 light years from the Sun and it is moving towards the Sun at the speed of 4 kilometers per second.

500.00 pc
1,630.00 ly
-4 km/s
-0.016 arcsec/year
0.014 arcsec/year

Spectral properties of HR7791

HR7791 belongs to spectral class K4 and has a luminosity class of III corresponding to a giant star.


The red dot in the diagram below shows where HR7791 is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of HR7791. Attribution: Richard Powell / CC BY-SA

HR7791 star system properties

HR7791 is a visual double star which can be observed only with the help of very large telescopes. The table below shows key information about the HR7791 double sysyem:

6.5 arcsec

Alternative designations of HR7791