Universe Guide


Omicron Capricorni, 12 Capricorni, HD195093, HIP101120

Omicron Capricorni is a blue main sequence dwarf star that can be located in the constellation of Capricornus. Omicron Capricorni is the brightest star in Capricornus based on the Hipparcos 2007 apparent magnitude. The star can not be seen by the naked eye, you need a telescope to see it.

Omicron Capricorni is the Bayer Classification for the star. HIP101120 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD195093.

Location of Omicron Capricorni

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 Omicron Capricorni, the location is 20h 29m 52.58 and -18d35`10.2 .

Omicron Capricorni Luminosity

Luminosity is the amount of energy that a star pumps out and its relative to the amount that our star, the Sun gives out. The figure of 9.0000000 that I have given is based on the Spectral Types page that I have found on the Internet. You might find a different figure, one that may have been calculated rather than generalised that I have done. The figure is always the amount times the luminosity of the Sun. It is an imprecise figure because of a number of factors including but not limited to whether the star is a variable star and distance.

Physical Properties (Colour, Temperature, Radius) of Omicron Capricorni

Omicron Capricorni has a spectral type of A7/A8V. This means the star is a blue main sequence dwarf star. The star has a B-V Colour Index of 0.22 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 7,650 Kelvin.

Omicron Capricorni Radius has been calculated as being 1.00 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 695,071.25.km. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

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

Omicron Capricorni Apparent and Absolute Magnitudes

Omicron Capricorni has an apparent magnitude of 6.74 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 3.63 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 Omicron Capricorni

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 23.89 which gave the calculated distance to Omicron Capricorni as 136.53 light years away from Earth or 41.86 parsecs. It would take a spaceship travelling at the speed of light, 136.53 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.

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.

Omicron Capricorni Facts

Alternative Names

Flamsteed Name12 Capricorni
Flamsteed Short Name12 Cap
Bayer DesignationOmicron Capricorni
Hipparcos Library I.D.101120
Bonner DurchmusterungBD-19 5830
Henry Draper Designation195093

Visual Facts

Star Typemain sequence dwarf star
Visual / Apparent Magnitude6.74
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)20h 29m 52.58
Declination (Dec.)-18d35`10.2
Galactic Latitude-29.78 degrees
Galactic Longitude26.07 degrees
1997 Distance from Earth23.89 Parallax (milliarcseconds)
 136.53 Light Years
 41.86 Parsecs
B-V Index0.22
Radial Velocity-9.10 ± 0.60 km/s
Spectral TypeA7/A8V
Colour(A) blue

Estimated Facts

Luminosity (x the Sun)9.0000000
Calculated Effective Temperature7,650 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

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