30 Ophiuchi

Below the horizon. Rise: 12:37 | Tran: 18:13 | Set: 23:50

Alt: -27.44° Az: 301.19° Direction: West-North-West

30 Ophiuchi is a variable and double giant star of spectral class K4 in the constellation of Ophiuchus.

30 Ophiuchi visual magnitude is 4.82. Because of its moderate brightness, 30 Ophiuchi is easily visible to the naked eye from locations with dark skies, while it might be barely visible, or not visible at all, from light-polluted skies.

DSS2 image of 30 Ophiuchi. The red arrow shows the motion of 30 Ophiuchi during the next 10000 years (-6.83 arcmin in Right Ascension and -12.50 arcmin in declination);

Celestial Coordinates

Apparent

Right Ascension 17h 02m 21s

Declination -04° 15’ 25”

Hour Angle 08h 41m 41s

Sideral Time 01h 44m 03s

J2000

Right Ascension 17h 01m 03s

Declination -04° 13’ 21”

Galactic Coordinates

Galactic Longitude 15.58°

Galactic Latitude 22.18°

Finder Chart

Simplified finder chart for 30 Ophiuchi.

Magnitude, Color, Spectral Class

Color ⬤

Magnitude 4.82

Class Giant

Absolute magnitude -0.63

Spectral Type K4III

Color Index (B-V) 1.48

Temperature 3824K

The red dot in the diagram below shows where 30 Ophiuchi is situated in the Hertzsprung–Russell diagram.

H-R diagram showing the position of 30 Ophiuchi. Attribution: Richard Powell / CC BY-SA

Star System Properties

30 Ophiuchi is a visual double star which can be observed with the help of small or medium telescopes. The table below shows key information about the 30 Ophiuchi double sysyem:

Main star magnitude 4.82

Secondary star magnitude 9.62

Magnitude difference 4.8

Separation 94.1 arcsec

Distance, Radial Speed, Proper Motion

30 Ophiuchi is distant 401.97 light years from the Sun and it is moving towards the Sun at the speed of 7 kilometers per second.

Distance (parsec) 123.30

Distance (light year) 401.97

Radial Speed -7 km/s

Proper Motion RA -0.041 arcsec/y

Proper Motion Dec -0.075"/y

Alternative Designations

Flamsteed designation 30 Ophiuchi

Henry Draper Catalogue HD153687

SAO Catalogue SAO141483

Hipparcos Catalogue HIP83262

Durchmusterung Catalogue BD-04 4215

FK5 Catalogue 1445

General Catalogue of Variable Stars 8111

Visibility from Your Location

Today's 30 Ophiuchi rise, transit and set times from Greenwich, UK are the following (all times relative to the local timezone Europe/London):

Azimuth: 94.3° RISE 12:37

Max altitude: 34.3° TRANSIT 18:13

Azimuth: 265.7° SET 23:50

Name:	Greenwich, UK
Latitude:	51° 28' 48.0" N
Longitude:	0° 0' 0.0" E
Timezone:	Europe/London

Location

Other stars in Ophiuchus