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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 6:49  
clear_day Transit: 12:50  
SunsetSet: 18:50 south
wb_twilight Astronomical TwilightWhat's Visible Now
All Constellations » Hercules » 

51 Herculis

Altitude: 50.7°   Azimuth: 241.6°   Direction: West-South-West

51 Herculis is a hypergiant star in the constellation of Hercules.

51 Herculis visual magnitude is 5.04. Because of its reltive faintness, 51 Herculis 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 51 Herculis:


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

Altitude: 50.7°
Azimuth: 241.6°
Direction: West-South-West

Celestial coordinates and finder chart of 51 Herculis

51 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 51 Herculis are provided in the following table:

16h 51m 45s
+24° 39’ 23”

The simplified sky map below shows the position of 51 Herculis in the sky:

Finder chart 51 Herculis star
Simplified finder chart for 51 Herculis.

Visibility of 51 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 51 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: 65.3°
Max altitude: 63.2°
Azimuth: 294.7°

Digitized Sky Survey image of 51 Herculis

The image below is a photograph of 51 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 51 Herculis is 0.011 arcsec per year in Right Ascension and 0.006 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of 51 Herculis star
DSS2 image of 51 Herculis. The red arrow shows the motion of 51 Herculis during the next 10000 years (1.83 arcmin in Right Ascension and 1.00 arcmin in declination);

Distance of 51 Herculis from the Sun and relative movement

51 Herculis is distant 758.14 light years from the Sun and it is moving towards the Sun at the speed of 16 kilometers per second.

232.56 pc
758.14 ly
-16 km/s
0.011 arcsec/year
0.006 arcsec/year

Spectral properties of 51 Herculis

51 Herculis belongs to spectral class K0 and has a luminosity class of III corresponding to a hypergiant star.


The red dot in the diagram below shows where 51 Herculis is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of 51 Herculis. Attribution: Richard Powell / CC BY-SA

Alternative designations of 51 Herculis

51 Herculis