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public  Greenwich, UK Greenwich, UK  ⓘ
TimezoneEurope/London
Sunrise: 7:53 
Transit: 11:52 
Sunset: 15:50
wb_twilight   (Nautical Twilight)  
What's Visible Now • Tonight Timeline
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All Constellations » Ophiuchus » 

τ Ophiuchi (tau Ophiuchi)

Below the horizon.  Rise: 7:36 | Tran: 12:53 | Set: 18:10
Alt: -5.22°   Az: 96.57°   Direction: East

τ Ophiuchi is a variable and multiple main-sequence star of spectral class F2 in the constellation of Ophiuchus.

τ Ophiuchi visual magnitude is 5.24. Because of its faintness, τ Ophiuchi is visible to the naked eye only from locations with very dark skies, while it is not visible at all from skies affected by light pollution.

Image of τ Ophiuchi (tau Ophiuchi) star
DSS2 image of τ Ophiuchi. The red arrow shows the motion of τ Ophiuchi during the next 10000 years (4.67 arcmin in Right Ascension and -6.17 arcmin in declination);

Celestial Coordinates

Apparent

18h 04m 26s
-08° 10’ 41”
18h 07m 31s
12h 11m 57s

J2000

18h 03m 04s
-08° 10’ 50”

Galactic Coordinates

20.06°
6.87°

Finder Chart

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Finder chart for τ Ophiuchi (tau Ophiuchi).

Magnitude, Color, Spectral Class

5.24
Main-sequence

1.66
F2V
6989K

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

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

Star System Properties

τ Ophiuchi is a visual double star which can be observed with the help of medium or large telescopes. The table below shows key information about the τ Ophiuchi double sysyem:

5.24
5.94
0.7
1.9 arcsec

Distance, Radial Speed, Proper Motion

τ Ophiuchi is distant 169.61 light years from the Sun and it is moving towards the Sun at the speed of 40 kilometers per second.

52.03
169.61
-40 km/s
0.028 arcsec/y
-0.037"/y

Alternative Designations

τ Ophiuchi
(tau Ophiuchi)
69 Ophiuchi
SAO142050
SAO142050
Gl 700.1A

Visibility from Your Location

Today's τ Ophiuchi (tau Ophiuchi) rise, transit and set times from Greenwich, UK are the following (all times relative to the local timezone Europe/London):

Azimuth: 98.2°
Max altitude: 30.3°
Azimuth: 261.8°