Universe Guide

11 Ursae Minoris - HD136726 - HIP74793

11 Ursae Minoris is an orange to red giant star that can be located in the constellation of UrsaMinor. It is calculated at being 1.560 Billion Years old. This information comes from ExoPlanet. HIP74793 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD136726. 11 Ursae Minoris has alternative name(s), Pherkad Minor , 11 UMi. 11 Ursae Minoris has at least 1 Extrasolar Planets believed to be in orbit around the star.

Location of 11 Ursae Minoris

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 11 Ursae Minoris, the location is 15h 17m 05.88 and +71 d 49 ` 26.0 .

Proper Motion of 11 Ursae Minoris

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 010.00 ± 000.00 towards the north and 004.00 ± 000.00 east if we saw them in the horizon.

11 Ursae Minoris 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 45.0000000 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, Metallicity, Age, Mass, Radius) of 11 Ursae Minoris

11 Ursae Minoris has a spectral type of K4III. This means the star is an orange to red coloured giant star. The star has a B-V Colour Index of 1.36 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,224 Kelvin.

11 Ursae Minoris has been calculated as 21.55 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 14,994,932.92.km. The star's solar mass is 1.80 times that of the Sun's. The Sun's Mass is 1,989,100,000,000,000,000,000 billion kg. which to calculate using this website is too large. To give idea of size, the Sun is 99.86% the mass of the solar system.

The star's metallicity is 0.040000, this value is the fractional amount of the star that is not Hydrogen (X) or Helium (Y). An older star would have a high metallicity whereas a new star would have a lower one.

The star is believed to be about 1.56 Billion years old. To put in context, the Sun is believed to be about five billion years old and the Universe is about 13.8 billion years old.

11 Ursae Minoris Apparent and Absolute Magnitudes

11 Ursae Minoris has an apparent magnitude of 5.02 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 -0.46 If you used the 2007 Parallax value, you would get an absolute magnitude of -0.46. 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 11 Ursae Minoris

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 8.00 which gave the calculated distance to 11 Ursae Minoris as 407.70 light years away from Earth or 125 parsecs. In 2007, Hipparcos data was revised with a new parallax of 8.00 which put 11 Ursae Minoris at a distance of 407.70 light years or 125 parsecs.

It would take a spaceship travelling at the speed of light, 407.70 years using the 1997 distance 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 Stellar Age, Metallicity or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

11 Ursae Minoris Facts

Traditional Name11 Ursae Minoris
Short Name11 UMi
Alternative Name(s)Pherkad Minor
Hipparcos Library I.D.74793
Bonner DurchmusterungBD+72 678
Henry Draper Designation136726
Celestial TypeStar
Age1.560 Billions of Years
Absolute Magnitude-0.46 / -0.46
Apparent Magnitude5.02
Right Ascension (R.A.)15h 17m 05.88
Declination (Dec.)+71 d 49 ` 26.0
1997 Distance from Earth8.00 Parallax (milliarcseconds)
 407.70 Light Years
 125 Parsecs
2007 Distance from Earth8.00 Parallax (milliarcseconds)
 407.70 Light Years
 125 Parsecs
Proper Motion Dec.10.00 ± 0.00 milliarcseconds/year
Proper Motion RA.4.00 ± 0.00 milliarcseconds/year
B-V Index1.36
Spectral TypeK4III
Colour(K) Orange to Red
Star Typegiant star
Exoplanet Count1
Radius (x the Sun)21.55
Luminosity (x the Sun)45.0000000
Calculated Effective Temperature4,224 Kelvin
Mass Compared to the Sun1.80

List of Extrasolar Planets orbiting 11 Ursae Minoris

NameMass (Jupiters)Orbital Period (Days)EccentricityDiscoveredSemi-Major AxisPeriastronLongitudeInclination
11 UMi b11.2516.2200.0820091.54118.000

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