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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
SunriseRise: 5:44  
clear_day Transit: 12:03  
SunsetSet: 18:24
sleep NighttimeWhat's Visible Now?
All Constellations » Ophiuchus » 

θ Ophiuchi (theta Ophiuchi)

Altitude: -20.4°   Azimuth: 104.9°   Direction: East-South-East

θ Ophiuchi is a variable and double sub-giant star in the constellation of Ophiuchus.

θ Ophiuchi visual magnitude is 3.27. Because of its moderate brightness, θ Ophiuchi should be easily visible from locations with dark skies, while it can be barely visible, or not visible at all, from skies affected by light pollution.

The proper motion of θ Ophiuchi is -0.004 arcsec per year in Right Ascension and -0.02 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of θ Ophiuchi (theta Ophiuchi) star
DSS2 image of θ Ophiuchi. The red arrow shows the motion of θ Ophiuchi during the next 10000 years (-0.67 arcmin in Right Ascension and -3.33 arcmin in declination);

Key facts about θ Ophiuchi

3.27
Sub-giant

θ Ophiuchi (theta Ophiuchi) is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -20.4°
Azimuth: 104.9°
Direction: East-South-East

Celestial coordinates and finder chart of θ Ophiuchi

θ Ophiuchi 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 θ Ophiuchi are provided in the following table:

17h 22m 00s
-24° 59’ 57”
0.46°
6.55°
Ophiuchus

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

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

Visibility of θ Ophiuchi 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 Ophiuchi (theta Ophiuchi) 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: 115.0°
Max altitude: 13.5°
Azimuth: 245.0°

Distance of θ Ophiuchi from the Sun and relative movement

θ Ophiuchi is distant 563.04 light years from the Sun and it is moving towards the Sun at the speed of 2 kilometers per second.

172.71 pc
563.04 ly
-2 km/s
-0.004 arcsec/year
-0.02 arcsec/year

Spectral properties of θ Ophiuchi

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

-2.92
B2IV
14087K

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

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

θ Ophiuchi star system properties

θ Ophiuchi 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 θ Ophiuchi double sysyem:

3.27
5.27
2
0 arcsec

Alternative designations of θ Ophiuchi

θ Ophiuchi
(theta Ophiuchi)
42 Ophiuchi
SAO185320
SAO185320