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 » 

θ Herculis (theta Herculis)

Altitude: 62.2°   Azimuth: 107.3°   Direction: East-South-East

θ Herculis is a variable bright giant star in the constellation of Hercules.

θ Herculis visual magnitude is 3.86. Because of its moderate brightness, θ 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 θ Herculis:

Bright giant

θ Herculis (theta Herculis) is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 62.2°
Azimuth: 107.3°
Direction: East-South-East

Celestial coordinates and finder chart of θ Herculis

θ 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 θ Herculis are provided in the following table:

17h 56m 15s
+37° 15’ 02”

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

Finder chart θ Herculis (theta Herculis) star
Simplified finder chart for θ Herculis (theta Herculis).

Visibility of θ 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 θ Herculis (theta 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: 52.7°
Max altitude: 75.8°
Azimuth: 307.3°
θ Herculis (theta Herculis) is above the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of θ Herculis

The image below is a photograph of θ 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 θ Herculis is 0.004 arcsec per year in Right Ascension and 0.006 arcsec per year in Declination and the associated displacement for the next 100000 years is represented with the red arrow.

Image of θ Herculis (theta Herculis) star
DSS2 image of θ Herculis. The red arrow shows the motion of θ Herculis during the next 100000 years (6.67 arcmin in Right Ascension and 10.00 arcmin in declination);

Distance of θ Herculis from the Sun and relative movement

θ Herculis is distant 669.40 light years from the Sun and it is moving towards the Sun at the speed of 27 kilometers per second.

205.34 pc
669.40 ly
-27 km/s
0.004 arcsec/year
0.006 arcsec/year

Spectral properties of θ Herculis

θ Herculis belongs to spectral class K1 and has a luminosity class of II corresponding to a bright giant star.


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

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

Alternative designations of θ Herculis

θ Herculis
(theta Herculis)
91 Herculis