123 G. Oph is a red pulsating giant star that can be located in the constellation of Ophiuchus. HIP is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD. The Id of the star in the Gould Star Catalogue is . Stars in the southern hemisphere are more likely to have a Gould Id than the northern hemisphere. For example, there are no Gould classified stars in Ursa Major.
The location of the star in the galaxy is determined by the Right Ascension (R.A.) and Declination (Dec.), these are equivalent to the Longitude and Latitude on the Earth. The Right Ascension is how far expressed in time (hh:mm:ss) the star is from celestial equator. The Declination is how up or down compared to the celestial equator and is expressed in degrees. For 123 G. Oph, the location is 17h 19m 46.49 and +02 d 08`22.1 .
123 G. Oph has a spectral type of M5III. This means the star is (M) red coloured (III) giant. 123 G. Oph lies at a distance of 599.56 light years away from our Sun and our planet Earth or to put it another way, 183.65 parsecs away from the Sun.
123 G. Oph has an apparent magnitude of 6.43 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. Magnitude, whether it be apparent/visual or absolute magnitude is measured by a number, the smaller the number, the brighter the Star is. Our own Sun is the brightest star and therefore has the lowest of all magnitudes, -26.74. A faint star will have a high number. The stars temperature has been calculated at between 2400 and 3700 based on the Class Type and lookup at Wikipedia-Stellar Classification
The star is a pulsating Semiregular s, which are giants or supergiants of intermediate and late spectral variable type which means that its size changes over time. The Variable Type is usually named after the first star of that type to be spotted. This is a some uncertainty as to the type but the type mentioned is the current variable star classification for this star. 123 G. Oph brightness ranges from a magnitude of 7.000 to a magnitude of 6.000 over its variable period. The smaller the magnitude, the brighter the star.
|Traditional Name||123 G. Oph|
|Short Name||V2113 Oph|
|Hipparcos Library I.D.||84780|
|Henry Draper Designation||156860|
|Right Ascension (R.A.)||17h 19m 46.49|
|Declination (Dec.)||+02 d 08`22.1|
|Distance from the Sun / Earth||599.56 Light Years|
|Star Type||(III) giant.|
|Variable Star Class||Pulsating|
|Variable Star Type||Semiregular s, which are giants or supergiants of intermediate and late spectral probably|
|Variable Magnitude Range (Brighter - Dimmer)||6.000 - 7.000|
|Calculated Temperature Range||2,400.00 - 3,700.00|