Universe Guide


10 Leonis - HD83240 - HIP47205

10 Leonis is a orange to red giant star that can be located in the constellation of Leo. HIP47205 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD83240. The Id of the star in the Gould Star Catalogue is 4. 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. 10 Leonis has alternative name(s), 10 Leonis , 10 Leo.

Location of 10 Leonis

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 10 Leonis, the location is 09h 37m 12.71 and +06d50`08.8 .

Proper Motion of 10 Leonis

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 12.54 ± 0.56 miliarcseconds/year towards the north and -68.07 ± 0.65 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of 10 Leonis

10 Leonis has a spectral type of K1IIIvar. This means the star is a orange to red giant star. The star has a B-V Colour Index of 1.05 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,755 Kelvin.

10 Leonis has been calculated as 9.52 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 6,623,368.73.km.

10 Leonis Apparent and Absolute Magnitudes

10 Leonis has an apparent magnitude of 5.00 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 0.80 If you used the 2007 Parallax value, you would get an absolute magnitude of 0.62. 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 10 Leonis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 14.45 which gave the calculated distance to 10 Leonis as 225.72 light years away from Earth or 69.20 parsecs. It would take a spaceship travelling at the speed of light, 225.72 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 13.28 which put 10 Leonis at a distance of 245.60 light years or 75.30 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.

10 Leonis Facts

Alternative Names

Traditional/Proper Name10 Leonis
Short Name10 Leo
Alternative Name(s)10 Leonis
Hipparcos Library I.D.47205
Bonner DurchmusterungBD+07 2160
Gould I.D.4
Henry Draper Designation83240

Visual Facts

Star Typegiant star
Absolute Magnitude0.80 / 0.62
Apparent Magnitude5.00
Right Ascension (R.A.)09h 37m 12.71
Declination (Dec.)+06d50`08.8
1997 Distance from Earth14.45 Parallax (milliarcseconds)
 225.72 Light Years
 69.20 Parsecs
2007 Revised Distance from Earth13.28 Parallax (milliarcseconds)
 245.60 Light Years
 75.30 Parsecs
Proper Motion Dec.12.54 ± 0.56 milliarcseconds/year
Proper Motion RA.-68.07 ± 0.65 milliarcseconds/year
B-V Index1.05
Spectral TypeK1IIIvar
Colour(K) Orange to Red

Estimated Facts

Radius (x the Sun)9.52
Calculated Effective Temperature4,755 Kelvin

Sources and Links

SIMBAD SourceLink

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