Your Guide to the Solar System and the Night Sky
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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 4:48  
clear_day Transit: 12:56  
SunsetSet: 21:05 south
wb_twilight Nautical TwilightWhat's Visible Now
All Constellations » Cygnus » 


HR7640 is a main-sequence star in the constellation of Cygnus.

HR7640 visual magnitude is 5.49. Because of its reltive faintness, HR7640 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 HR7640:

HR7640 is above the horizon from Greenwich, United Kingdom edit_location_alt. Altitude: 68°.

Celestial coordinates and finder chart of HR7640

HR7640 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 HR7640 are provided in the following table:

19h 58m 37s
+30° 59’ 00”

The simplified sky map below shows the position of HR7640 in the sky:

Finder chart HR7640 star
Simplified finder chart for HR7640.

Visibility of HR7640 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 HR7640 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: 59.0°
Max altitude: 69.5°
Azimuth: 301.0°
HR7640 is above the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of HR7640

The image below is a photograph of HR7640 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 HR7640 is 0.041 arcsec per year in Right Ascension and 0.003 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of HR7640 star
DSS2 image of HR7640. The red arrow shows the motion of HR7640 during the next 10000 years (6.83 arcmin in Right Ascension and 0.50 arcmin in declination);

Distance of HR7640 from the Sun and relative movement

HR7640 is distant 544.24 light years from the Sun and it is moving towards the Sun at the speed of 7 kilometers per second.

166.94 pc
544.24 ly
-7 km/s
0.041 arcsec/year
0.003 arcsec/year

Spectral properties of HR7640

HR7640 belongs to spectral class B9 and has a luminosity class of V corresponding to a main-sequence star.


The red dot in the diagram below shows where HR7640 is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of HR7640. Attribution: Richard Powell / CC BY-SA

Alternative designations of HR7640