21 Ophiuchi
21 Ophiuchi is a double main-sequence star of spectral class A2 in the constellation of Ophiuchus.
21 Ophiuchi visual magnitude is 5.51. Because of its faintness, 21 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.

Celestial Coordinates
Apparent
J2000
Galactic Coordinates
Finder Chart
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Finder chart for 21 Ophiuchi.
Magnitude, Color, Spectral Class

The red dot in the diagram below shows where 21 Ophiuchi is situated in the Hertzsprung–Russell diagram.

Star System Properties
21 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 21 Ophiuchi double sysyem:
Distance, Radial Speed, Proper Motion
21 Ophiuchi is distant 344.97 light years from the Sun and it is moving towards the Sun at the speed of 26 kilometers per second.
Alternative Designations
Visibility from Your Location
Today's 21 Ophiuchi rise, transit and set times from Greenwich, UK are the following (all times relative to the local timezone Europe/London):