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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: 7:41  
clear_day Transit: 11:47  
SunsetSet: 15:53 south
wb_twilight Nautical TwilightWhat's Visible Now?
All Constellations » Vulpecula » 


Altitude: -2.9°   Azimuth: 40.8°   Direction: North-East

HR7739 is a variable and multiple main-sequence star in the constellation of Vulpecula.

HR7739 visual magnitude is 4.78. Because of its moderate brightness, HR7739 should be easily visible from locations with dark skyes, while it can be barely visible, or not visible at all, from skyes affected by light pollution.

The table below summarizes the key facts about HR7739:


HR7739 is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -2.9°
Azimuth: 40.8°
Direction: North-East

Celestial coordinates and finder chart of HR7739

HR7739 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 HR7739 are provided in the following table:

20h 15m 15s
+25° 35’ 30”

The simplified sky map below shows the position of HR7739 in the sky:

Finder chart HR7739 star
Simplified finder chart for HR7739.

Visibility of HR7739 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 HR7739 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: 64.4°
Max altitude: 64.1°
Azimuth: 295.6°

Digitized Sky Survey image of HR7739

The image below is a photograph of HR7739 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 HR7739 is 0.008 arcsec per year in Right Ascension and -0.006 arcsec per year in Declination and the associated displacement for the next 100000 years is represented with the red arrow.

Image of HR7739 star
DSS2 image of HR7739. The red arrow shows the motion of HR7739 during the next 100000 years (13.33 arcmin in Right Ascension and -10.00 arcmin in declination);

Distance of HR7739 from the Sun and relative movement

HR7739 is distant 1,198.53 light years from the Sun and it is moving towards the Sun at the speed of 7 kilometers per second.

367.65 pc
1,198.53 ly
-7 km/s
0.008 arcsec/year
-0.006 arcsec/year

Spectral properties of HR7739

HR7739 belongs to spectral class B3 and has a luminosity class of V corresponding to a main-sequence star.


The red dot in the diagram below shows where HR7739 is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of HR7739. Attribution: Richard Powell / CC BY-SA

HR7739 star system properties

HR7739 is a visual double star which can be observed with the help of large telescopes. The table below shows key information about the HR7739 double sysyem:

0.7 arcsec

Alternative designations of HR7739