Universe Guide


Gamma Delphini B - HD197964 - HIP102532

Gamma Delphini B is a orange to red subgiant star that can be located in the constellation of Delphinus. Gamma Delphini B is the Bayer Classification for the star. HIP102532 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD197964. Gamma Delphini B has alternative name(s), 12 Delphini , 12 Del. Gamma Delphini B is a multiple star system with 2 stars orbiting in its solar system.

Location of Gamma Delphini B

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 along the celestial equator. If the R.A. is positive then its eastwards. The Declination is how far north or south the star is compared to the celestial equator and is expressed in degrees. For Gamma Delphini B, the location is 20h 46m 39.52 and +16d07`29.2 .

Proper Motion of Gamma Delphini B

All stars like planets orbit round a central spot, in the case of planets, its the central star such as the Sun. In the case of a star, its the galactic centre. The constellations that we see today will be different than they were 50,000 years ago or 50,000 years from now. Proper Motion details the movements of these stars and are measured in milliarcseconds. The star is moving -199.96 ± 000.71 towards the north and -024.17 ± 001.32 east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of Gamma Delphini B

Gamma Delphini B has a spectral type of K1IV. This means the star is a orange to red subgiant star. The star has a B-V Colour Index of 1.04 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,773 Kelvin.

Gamma Delphini B has been calculated as 5.93 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 4,128,451.55.km.

The star has a companion star which is in orbit close by, it has at least the following companions in close orbit, Gamma Delphini.

Gamma Delphini B Apparent and Absolute Magnitudes

Gamma Delphini B has an apparent magnitude of 4.27 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. If you used the 1997 Parallax value, you would get an absolute magnitude of 1.81 If you used the 2007 Parallax value, you would get an absolute magnitude of 1.33. 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.

Distance to Gamma Delphini B

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 32.14 which gave the calculated distance to Gamma Delphini B as 101.48 light years away from Earth or 31.11 parsecs. It would take a spaceship travelling at the speed of light, 101.48 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.

In 2007, Hipparcos data was revised with a new parallax of 25.82 which put Gamma Delphini B at a distance of 126.32 light years or 38.73 parsecs. It should not be taken as though the star is moving closer or further away from us. It is purely that the distance was recalculated.

Source of Information

The source of the information if it has a Hip I.D. is from Simbad, the Hipparcos data library based at the University at Strasbourg, France. Hipparcos was a E.S.A. satellite operation launched in 1989 for four years. The items in red are values that I've calculated so they could well be wrong. Information regarding Stellar Age, Metallicity or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

Gamma Delphini B Facts

Alternative Names

Short Name12 Del
Bayer DesignationGamma Delphini B
Alternative Name(s)12 Delphini
Hipparcos Library I.D.102532
Bonner DurchmusterungBD+15 4255
Henry Draper Designation197964

Visual Facts

Star Typesubgiant star
Absolute Magnitude1.81 / 1.33
Apparent Magnitude4.27
Right Ascension (R.A.)20h 46m 39.52
Declination (Dec.)+16d07`29.2
1997 Distance from Earth32.14 Parallax (milliarcseconds)
 101.48 Light Years
 31.11 Parsecs
2007 Revised Distance from Earth25.82 Parallax (milliarcseconds)
 126.32 Light Years
 38.73 Parsecs
Proper Motion Dec.-199.96 ± 0.71 milliarcseconds/year
Proper Motion RA.-24.17 ± 1.32 milliarcseconds/year
B-V Index1.04
Spectral TypeK1IV
Colour(K) Orange to Red

Companions (Multi-Star and Exoplanets) Facts

Stars in Solar System2
Companion StarsGamma Delphini

Estimated Facts

Radius (x the Sun)5.93
Calculated Effective Temperature4,773 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

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