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Yed Posterior - ε Ophiuchi (epsilon Ophiuchi)

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:

Color of Yed Posterior ⬤

Magnitude of Yed Posterior 3.24

Class Giant

VISIBILITY RIGHT NOW Yed Posterior - ε Ophiuchi (epsilon Ophiuchi) is above the horizon from Greenwich, United Kingdom [change]. Altitude: 1°.

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:

Right Ascension J2000 16h 18m 19s

Declination J2000 -04° 41’ 32”

Galactic Longitude 8.56°

Galactic Latitude 30.81°

Constellation Ophiuchus

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 [change]
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 [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 94.7° RISE 22:42

Max altitude: 33.8° TRANSIT 4:20

Azimuth: 265.3° SET 9:55

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

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.

Distance (parsec) 32.96 pc

Distance (light year) 107.45 ly

Heliocentric radial velocity -10 km/s

Proper Motion RA 0.085 arcsec/year

Proper Motion Dec 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.

Absolute magnitude 0.65

Spectral Type G9III

Color Index (B-V) 0.96

Temperature of Yed Posterior 4841K

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

Main star magnitude 3.24

Secondary star magnitude 12.34

Magnitude difference 9.1

Separation 110.6 arcsec

Alternative designations of Yed Posterior

Proper Name Yed Posterior

Bayer designation ε Ophiuchi
(epsilon Ophiuchi)

Flamsteed designation 2 Ophiuchi

Henry Draper Catalogue HD146791

SAO Catalogue SAO141086

Hipparcos Catalogue HIP79882

Durchmusterung Catalogue BD-04 4086

Gliese Catalogue NN 3949

FK5 Catalogue 605

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Other stars in Ophiuchus