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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 6:46  
clear_day Transit: 12:51  
SunsetSet: 18:55 south
wb_twilight Astronomical TwilightWhat's Visible Now
All Constellations » Hercules » 

73 Herculis

Altitude: -14.2°   Azimuth: 344.4°   Direction: North-North-West

73 Herculis is a variable hypergiant star in the constellation of Hercules.

73 Herculis visual magnitude is 5.74. Because of its reltive faintness, 73 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 73 Herculis:


73 Herculis is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -14.2°
Azimuth: 344.4°
Direction: North-North-West

Celestial coordinates and finder chart of 73 Herculis

73 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 73 Herculis are provided in the following table:

17h 24m 06s
+22° 57’ 37”

The simplified sky map below shows the position of 73 Herculis in the sky:

Finder chart 73 Herculis star
Simplified finder chart for 73 Herculis.

Visibility of 73 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 73 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: 67.0°
Max altitude: 61.5°
Azimuth: 293.0°

Digitized Sky Survey image of 73 Herculis

The image below is a photograph of 73 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 73 Herculis is -0.046 arcsec per year in Right Ascension and -0.032 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of 73 Herculis star
DSS2 image of 73 Herculis. The red arrow shows the motion of 73 Herculis during the next 10000 years (-7.67 arcmin in Right Ascension and -5.33 arcmin in declination);

Distance of 73 Herculis from the Sun and relative movement

73 Herculis is distant 139.50 light years from the Sun and it is moving towards the Sun at the speed of 20 kilometers per second.

42.79 pc
139.50 ly
-20 km/s
-0.046 arcsec/year
-0.032 arcsec/year

Spectral properties of 73 Herculis

73 Herculis belongs to spectral class F0 and has a luminosity class of IV corresponding to a hypergiant star.


The red dot in the diagram below shows where 73 Herculis is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of 73 Herculis. Attribution: Richard Powell / CC BY-SA

Alternative designations of 73 Herculis

73 Herculis