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: 4:44  
clear_day Transit: 12:57  
SunsetSet: 21:11 south
wb_twilight Astronomical TwilightWhat's Visible Now
All Constellations » Hercules » 

μ Herculis (mu Herculis)

Altitude: 55.4°   Azimuth: 120.4°   Direction: East-South-East

μ Herculis is a multiple sub-giant star in the constellation of Hercules.

μ Herculis visual magnitude is 3.42. Because of its moderate brightness, μ 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 μ Herculis:


μ Herculis (mu Herculis) is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 55.4°
Azimuth: 120.4°
Direction: East-South-East

Celestial coordinates and finder chart of μ Herculis

μ Herculis 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 μ Herculis are provided in the following table:

17h 46m 27s
+27° 43’ 14”

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

Finder chart μ Herculis (mu Herculis) star
Simplified finder chart for μ Herculis (mu Herculis).

Visibility of μ 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 μ Herculis (mu 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: 62.3°
Max altitude: 66.2°
Azimuth: 297.7°
μ Herculis (mu Herculis) is above the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of μ Herculis

The image below is a photograph of μ 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 μ Herculis is -0.311 arcsec per year in Right Ascension and -0.751 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of μ Herculis (mu Herculis) star
DSS2 image of μ Herculis. The red arrow shows the motion of μ Herculis during the next 1000 years (-5.18 arcmin in Right Ascension and -12.52 arcmin in declination);

Distance of μ Herculis from the Sun and relative movement

μ Herculis is distant 27.38 light years from the Sun and it is moving towards the Sun at the speed of 16 kilometers per second.

8.40 pc
27.38 ly
-16 km/s
-0.311 arcsec/year
-0.751 arcsec/year

Spectral properties of μ Herculis

μ Herculis belongs to spectral class G5 and has a luminosity class of IV corresponding to a sub-giant star.


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

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

μ Herculis star system properties

μ 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 μ Herculis double sysyem:

33.8 arcsec

Alternative designations of μ Herculis

μ Herculis
(mu Herculis)
86 Herculis
Gl 695 A