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Kappa Draconis, 5 Draconis, HD109387, HIP61281

Kappa Draconis is a blue eruptive giant star that can be located in the constellation of Draco. Kappa Draconis is the brightest star in Draco based on the Hipparcos 2007 apparent magnitude. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

Kappa Draconis is the Bayer Classification for the star. HIP61281 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD109387.

Kappa Draconis has alternative name(s), kap Dra.

Location of Kappa Draconis

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 Kappa Draconis, the location is 12h 33m 29.04 and +69d47`17.6 .

Proper Motion of Kappa Draconis

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 10.68 ± 0.28 miliarcseconds/year towards the north and -58.79 ± 0.34 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of Kappa Draconis

Kappa Draconis has a spectral type of B6IIIp. This means the star is a blue giant star. The star is 7460.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24331.7854624000000000s. The star has a B-V Colour Index of -0.11 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 12,006 Kelvin.

Kappa Draconis Radius has been calculated as being 5.60 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 3,895,932.95.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 5.52. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures. The star's Iron Abundance is -0.65 with an error value of 9.99 Fe/H with the Sun has a value of 1 to put it into context.

Kappa Draconis Apparent and Absolute Magnitudes

Kappa Draconis has an apparent magnitude of 3.85 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 -2.07 If you used the 2007 Parallax value, you would get an absolute magnitude of -2.04. 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 Kappa Draconis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 6.55 which gave the calculated distance to Kappa Draconis as 497.96 light years away from Earth or 152.67 parsecs. It would take a spaceship travelling at the speed of light, 497.96 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 6.65 which put Kappa Draconis at a distance of 490.47 light years or 150.38 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.

The star's Galacto-Centric Distance is 7,460.00 Parsecs or 24,331.79 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

Variable Type of Kappa Draconis

The star is a eruptive Gamma Cassiopeiae 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. Kappa Draconis brightness ranges from a magnitude of 3.854 to a magnitude of 3.824 over its variable period. The smaller the magnitude, the brighter the star.

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 Metallicity and/or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

Kappa Draconis Facts

Alternative Names

Flamsteed Name5 Draconis
Flamsteed Short Name5 Dra
Short Namekap Dra
Bayer DesignationKappa Draconis
Hipparcos Library I.D.61281
Bonner DurchmusterungBD+70 703
Henry Draper Designation109387

Visual Facts

Star Typegiant star
Absolute Magnitude-2.07 / -2.04
Visual / Apparent Magnitude3.85
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)12h 33m 29.04
Declination (Dec.)+69d47`17.6
Galactic Latitude47.26 degrees
Galactic Longitude125.22 degrees
1997 Distance from Earth6.55 Parallax (milliarcseconds)
 497.96 Light Years
 152.67 Parsecs
2007 Revised Distance from Earth6.65 Parallax (milliarcseconds)
 490.47 Light Years
 150.38 Parsecs
Galacto-Centric Distance24,331.79 Light Years / 7,460.00 Parsecs
Proper Motion Dec.10.68 ± 0.28 milliarcseconds/year
Proper Motion RA.-58.79 ± 0.34 milliarcseconds/year
B-V Index-0.11
Radial Velocity-12.00 ± 0.30 km/s
Iron Abundance-0.65 ± 9.99 Fe/H
Spectral TypeB6IIIp
Colour(B) blue

Variable Star Details

Variable Star ClassEruptive
Variable Star TypeGamma Cassiopeiae
Variable Magnitude Range (Brighter - Dimmer)3.824 - 3.854

Estimated Facts

Calculated Effective Temperature12,006 Kelvin

Sources and Links

SIMBAD SourceLink

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