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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: 7:47  
clear_day Transit: 11:49  
SunsetSet: 15:50 south
sunny DaytimeWhat's Visible Now?
All Constellations » Hercules » 

102 Herculis

Altitude: 28.1°   Azimuth: 91.4°   Direction: East

102 Herculis is a double sub-giant star in the constellation of Hercules.

102 Herculis visual magnitude is 4.36. Because of its moderate brightness, 102 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 102 Herculis:


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

Altitude: 28.1°
Azimuth: 91.4°
Direction: East

Celestial coordinates and finder chart of 102 Herculis

102 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 102 Herculis are provided in the following table:

18h 08m 45s
+20° 48’ 51”

The simplified sky map below shows the position of 102 Herculis in the sky:

Finder chart 102 Herculis star
Simplified finder chart for 102 Herculis.

Visibility of 102 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 102 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: 69.2°
Max altitude: 59.3°
Azimuth: 290.8°

Digitized Sky Survey image of 102 Herculis

The image below is a photograph of 102 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 102 Herculis is -0.001 arcsec per year in Right Ascension and -0.005 arcsec per year in Declination and the associated displacement for the next 100000 years is represented with the red arrow.

Image of 102 Herculis star
DSS2 image of 102 Herculis. The red arrow shows the motion of 102 Herculis during the next 100000 years (-1.67 arcmin in Right Ascension and -8.33 arcmin in declination);

Distance of 102 Herculis from the Sun and relative movement

102 Herculis is distant 1,523.36 light years from the Sun and it is moving towards the Sun at the speed of 15 kilometers per second.

467.29 pc
1,523.36 ly
-15 km/s
-0.001 arcsec/year
-0.005 arcsec/year

Spectral properties of 102 Herculis

102 Herculis belongs to spectral class B2 and has a luminosity class of IV corresponding to a sub-giant star.


The red dot in the diagram below shows where 102 Herculis is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of 102 Herculis. Attribution: Richard Powell / CC BY-SA

102 Herculis star system properties

102 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 102 Herculis double sysyem:

23.4 arcsec

Alternative designations of 102 Herculis

102 Herculis