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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: 7:45  
clear_day Transit: 11:48  
SunsetSet: 15:51 south
sleep NighttimeWhat's Visible Now?
All Constellations » Hercules » 

109 Herculis

Altitude: 13.7°   Azimuth: 287.8°   Direction: West-North-West

109 Herculis is a variable and double giant star in the constellation of Hercules.

109 Herculis visual magnitude is 3.84. Because of its moderate brightness, 109 Herculis 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 109 Herculis:


109 Herculis is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 13.7°
Azimuth: 287.8°
Direction: West-North-West

Celestial coordinates and finder chart of 109 Herculis

109 Herculis is situated close to the celestial equator, as such, it is at least partly visible from both hemispheres in certain times of the year. Celestial coordinates for the J2000 equinox as well as galactic coordinates of 109 Herculis are provided in the following table:

18h 23m 41s
+21° 46’ 10”

The simplified sky map below shows the position of 109 Herculis in the sky:

Finder chart 109 Herculis star
Simplified finder chart for 109 Herculis.

Visibility of 109 Herculis 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 109 Herculis 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: 68.2°
Max altitude: 60.3°
Azimuth: 291.8°

Digitized Sky Survey image of 109 Herculis

The image below is a photograph of 109 Herculis 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 109 Herculis is 0.196 arcsec per year in Right Ascension and -0.242 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of 109 Herculis star
DSS2 image of 109 Herculis. The red arrow shows the motion of 109 Herculis during the next 1000 years (3.27 arcmin in Right Ascension and -4.03 arcmin in declination);

Distance of 109 Herculis from the Sun and relative movement

109 Herculis is distant 128.35 light years from the Sun and it is moving towards the Sun at the speed of 58 kilometers per second.

39.37 pc
128.35 ly
-58 km/s
0.196 arcsec/year
-0.242 arcsec/year

Spectral properties of 109 Herculis

109 Herculis belongs to spectral class K2 and has a luminosity class of III corresponding to a giant star.


The red dot in the diagram below shows where 109 Herculis is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of 109 Herculis. Attribution: Richard Powell / CC BY-SA

109 Herculis star system properties

109 Herculis 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 109 Herculis double sysyem:

221.8 arcsec

Alternative designations of 109 Herculis

109 Herculis