We use cookies to deliver essential features and to measure their performance. By using this site you accept our Privacy Policies.
A Complete Guide to the Solar System and the Night Sky
Donate now and help us to keep this site free and ad-free!
public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 7:52  
clear_day Transit: 11:51  
SunsetSet: 15:49 south
sleep NighttimeWhat's Visible Now?
All Constellations » Cygnus » 


Altitude: 21.8°   Azimuth: 22.9°   Direction: North-North-East

HR7781 is a multiple main-sequence star in the constellation of Cygnus.

HR7781 visual magnitude is 5.76. Because of its reltive faintness, HR7781 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 HR7781:


HR7781 is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 21.8°
Azimuth: 22.9°
Direction: North-North-East

Celestial coordinates and finder chart of HR7781

HR7781 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 HR7781 are provided in the following table:

20h 18m 24s
+55° 23’ 49”

The simplified sky map below shows the position of HR7781 in the sky:

Finder chart HR7781 star
Simplified finder chart for HR7781.

Visibility of HR7781 from your location

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

HR7781 is circumpolar and transits at 15:02 UTC (altitude: 86.1°)

Digitized Sky Survey image of HR7781

The image below is a photograph of HR7781 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 HR7781 is -0.006 arcsec per year in Right Ascension and -0.023 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of HR7781 star
DSS2 image of HR7781. The red arrow shows the motion of HR7781 during the next 10000 years (-1.00 arcmin in Right Ascension and -3.83 arcmin in declination);

Distance of HR7781 from the Sun and relative movement

HR7781 is distant 290.81 light years from the Sun and it is moving far from the Sun at the speed of 1 kilometers per second.

89.21 pc
290.81 ly
1 km/s
-0.006 arcsec/year
-0.023 arcsec/year

Spectral properties of HR7781

HR7781 belongs to spectral class A2 and has a luminosity class of V corresponding to a main-sequence star.


The red dot in the diagram below shows where HR7781 is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of HR7781. Attribution: Richard Powell / CC BY-SA

HR7781 star system properties

HR7781 is a visual double star which can be observed with the help of small or medium telescopes. The table below shows key information about the HR7781 double sysyem:

3.5 arcsec

Alternative designations of HR7781