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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 6:46  
clear_day Transit: 12:51  
SunsetSet: 18:55 south
sunny DaytimeWhat's Visible Now
All Constellations » Ophiuchus » 

73 Ophiuchi

Altitude: -3.5°   Azimuth: 79.1°   Direction: East

73 Ophiuchi is a variable and multiple main-sequence star in the constellation of Ophiuchus.

73 Ophiuchi visual magnitude is 5.73. Because of its reltive faintness, 73 Ophiuchi should be visible only from locations with dark skyes, while it is not visible at all from skyes affected by light pollution.

The table below summarizes the key facts about 73 Ophiuchi:


73 Ophiuchi is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -3.5°
Azimuth: 79.1°
Direction: East

Celestial coordinates and finder chart of 73 Ophiuchi

73 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 73 Ophiuchi are provided in the following table:

18h 09m 33s
+03° 59’ 35”

The simplified sky map below shows the position of 73 Ophiuchi in the sky:

Finder chart 73 Ophiuchi star
Simplified finder chart for 73 Ophiuchi.

Visibility of 73 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 73 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: 86.0°
Max altitude: 42.5°
Azimuth: 274.0°

Digitized Sky Survey image of 73 Ophiuchi

The image below is a photograph of 73 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 73 Ophiuchi is 0.038 arcsec per year in Right Ascension and -0.007 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of 73 Ophiuchi star
DSS2 image of 73 Ophiuchi. The red arrow shows the motion of 73 Ophiuchi during the next 10000 years (6.33 arcmin in Right Ascension and -1.17 arcmin in declination);

Distance of 73 Ophiuchi from the Sun and relative movement

73 Ophiuchi is distant 166.16 light years from the Sun and it is moving towards the Sun at the speed of 17 kilometers per second.

50.97 pc
166.16 ly
-17 km/s
0.038 arcsec/year
-0.007 arcsec/year

Spectral properties of 73 Ophiuchi

73 Ophiuchi belongs to spectral class F2 and has a luminosity class of V corresponding to a main-sequence star.


The red dot in the diagram below shows where 73 Ophiuchi is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of 73 Ophiuchi. Attribution: Richard Powell / CC BY-SA

73 Ophiuchi star system properties

73 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 73 Ophiuchi double sysyem:

0.3 arcsec

Alternative designations of 73 Ophiuchi

73 Ophiuchi