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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 6:49  
clear_day Transit: 12:50  
SunsetSet: 18:50 south
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All Constellations » Ophiuchus » 

Yed Posterior - ε Ophiuchi (epsilon Ophiuchi)

Altitude: 11.0°   Azimuth: 247.8°   Direction: West-South-West

Yed Posterior, also designated as ε Ophiuchi (epsilon Ophiuchi), is a double giant star in the constellation of Ophiuchus.

Yed Posterior visual magnitude is 3.24. Because of its moderate brightness, Yed Posterior 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 Yed Posterior:


Yed Posterior - ε Ophiuchi (epsilon Ophiuchi) is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 11.0°
Azimuth: 247.8°
Direction: West-South-West

Celestial coordinates and finder chart of Yed Posterior

Yed Posterior 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 Yed Posterior are provided in the following table:

16h 18m 19s
-04° 41’ 32”

The simplified sky map below shows the position of Yed Posterior in the sky:

Finder chart Yed Posterior - ε Ophiuchi (epsilon Ophiuchi) star
Simplified finder chart for Yed Posterior - ε Ophiuchi (epsilon Ophiuchi).

Visibility of Yed Posterior 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 Yed Posterior - ε Ophiuchi (epsilon 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: 94.7°
Max altitude: 33.8°
Azimuth: 265.3°

Digitized Sky Survey image of Yed Posterior

The image below is a photograph of Yed Posterior 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 Yed Posterior is 0.085 arcsec per year in Right Ascension and 0.041 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of Yed Posterior - ε Ophiuchi (epsilon Ophiuchi) star
DSS2 image of Yed Posterior. The red arrow shows the motion of Yed Posterior during the next 10000 years (14.17 arcmin in Right Ascension and 6.83 arcmin in declination);

Distance of Yed Posterior from the Sun and relative movement

Yed Posterior is distant 107.45 light years from the Sun and it is moving towards the Sun at the speed of 10 kilometers per second.

32.96 pc
107.45 ly
-10 km/s
0.085 arcsec/year
0.041 arcsec/year

Spectral properties of Yed Posterior

Yed Posterior belongs to spectral class G9 and has a luminosity class of III corresponding to a giant star.


The red dot in the diagram below shows where Yed Posterior is situated in the Hertzsprung–Russell diagram.

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

Yed Posterior star system properties

Yed Posterior 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 Yed Posterior double sysyem:

110.6 arcsec

Alternative designations of Yed Posterior

Yed Posterior
ε Ophiuchi
(epsilon Ophiuchi)