20 Ophiuchi

20 Ophiuchi is a sub-giant star in the constellation of Ophiuchus.

20 Ophiuchi visual magnitude is 4.65. Because of its moderate brightness, 20 Ophiuchi 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 20 Ophiuchi:

Color of 20 Ophiuchi ⬤

Magnitude of 20 Ophiuchi 4.65

Class Sub-giant

VISIBILITY RIGHT NOW 20 Ophiuchi is above the horizon from Greenwich, United Kingdom [change]. Altitude: 25°.

Celestial coordinates and finder chart of 20 Ophiuchi

20 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 20 Ophiuchi are provided in the following table:

Right Ascension J2000 16h 49m 50s

Declination J2000 -10° 46’ 59”

Galactic Longitude 8.04°

Galactic Latitude 20.93°

Constellation Ophiuchus

The simplified sky map below shows the position of 20 Ophiuchi in the sky:

Simplified finder chart for 20 Ophiuchi.

Visibility of 20 Ophiuchi from your location

Location: Greenwich, United Kingdom [change]
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

Today's 20 Ophiuchi rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 100.8° RISE 0:17

Max altitude: 27.7° TRANSIT 5:24

Azimuth: 259.2° SET 10:27

RIGHT NOW 20 Ophiuchi is above the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of 20 Ophiuchi

The image below is a photograph of 20 Ophiuchi 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 20 Ophiuchi is 0.096 arcsec per year in Right Ascension and -0.093 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

DSS2 image of 20 Ophiuchi. The red arrow shows the motion of 20 Ophiuchi during the next 1000 years (1.60 arcmin in Right Ascension and -1.55 arcmin in declination);

Distance of 20 Ophiuchi from the Sun and relative movement

20 Ophiuchi is distant 120.56 light years from the Sun and it is moving towards the Sun at the speed of 1 kilometers per second.

Distance (parsec) 36.98 pc

Distance (light year) 120.56 ly

Heliocentric radial velocity -1 km/s

Proper Motion RA 0.096 arcsec/year

Proper Motion Dec -0.093 arcsec/year

Spectral properties of 20 Ophiuchi

20 Ophiuchi belongs to spectral class F7 and has a luminosity class of IV corresponding to a sub-giant star.

Absolute magnitude 1.81

Spectral Type F7IV

Color Index (B-V) 0.47

Temperature of 20 Ophiuchi 6528K

The red dot in the diagram below shows where 20 Ophiuchi is situated in the Hertzsprung–Russell diagram.

H-R diagram showing the position of 20 Ophiuchi. Attribution: Richard Powell / CC BY-SA

Alternative designations of 20 Ophiuchi

Flamsteed designation 20 Ophiuchi

Henry Draper Catalogue HD151769

SAO Catalogue SAO160118

Hipparcos Catalogue HIP82369

Durchmusterung Catalogue BD-10 4394

FK5 Catalogue 1438

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Other stars in Ophiuchus