Universe Guide


79 G. Cen, HD103516, HIP58103

79 G. Cen is a blue very luminous supergiant star that can be located in the constellation of Centaurus. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

HIP58103 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD103516. The Id of the star in the Gould Star Catalogue is 79. 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.

79 G. Cen has alternative name(s), NSV 05385.

Location of 79 G. Cen

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 79 G. Cen, the location is 11h 55m 00.02 and -63d16`45.0 .

Proper Motion of 79 G. Cen

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 0.10 ± 0.20 miliarcseconds/year towards the north and -8.35 ± 0.28 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of 79 G. Cen

79 G. Cen has a spectral type of A3Ib. This means the star is a blue supergiant star. The star has a B-V Colour Index of 0.21 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 7,325 Kelvin.

79 G. Cen Radius has been calculated as being 30.29 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 21,076,952.52.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 66.27. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

79 G. Cen Apparent and Absolute Magnitudes

79 G. Cen has an apparent magnitude of 5.89 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 -3.59 If you used the 2007 Parallax value, you would get an absolute magnitude of -5.29. 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 79 G. Cen

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 1.27 which gave the calculated distance to 79 G. Cen as 2568.22 light years away from Earth or 787.40 parsecs. It would take a spaceship travelling at the speed of light, 2568.22 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 0.58 which put 79 G. Cen at a distance of 5623.51 light years or 1724.14 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. 79 G. Cen brightness ranges from a magnitude of 5.984 to a magnitude of 5.943 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.0 days (variability).

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.

79 G. Cen Facts

Alternative Names

Traditional/Proper Name79 G. Cen
Short NameNSV 05385
Hipparcos Library I.D.58103
Gould I.D.79
Henry Draper Designation103516

Visual Facts

Star Typesupergiant star
Absolute Magnitude-3.59 / -5.29
Visual / Apparent Magnitude5.89
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)11h 55m 00.02
Declination (Dec.)-63d16`45.0
Galactic Latitude-1.10 degrees
Galactic Longitude296.64 degrees
1997 Distance from Earth1.27 Parallax (milliarcseconds)
 2568.22 Light Years
 787.40 Parsecs
2007 Revised Distance from Earth0.58 Parallax (milliarcseconds)
 5623.51 Light Years
 1724.14 Parsecs
Proper Motion Dec.0.10 ± 0.20 milliarcseconds/year
Proper Motion RA.-8.35 ± 0.28 milliarcseconds/year
B-V Index0.21
Radial Velocity-25.90 ± 0.50 km/s
Spectral TypeA3Ib
Colour(A) blue

Variable Star Details

Mean Variability Period in Days0.027
Variable Magnitude Range (Brighter - Dimmer)5.943 - 5.984

Estimated Facts

Calculated Effective Temperature7,325 Kelvin

Sources and Links

SIMBAD SourceLink

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