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2 Ursae Minoris, 2 Cephei, HD5848, HIP5372

2 Ursae Minoris is a orange to red giant star that can be located in the constellation of Cepheus. 2 Ursae Minoris is the brightest star in Cepheus 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.

HIP5372 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD5848.

Location of 2 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 2 Ursae Minoris, the location is 01h 08m 44.16 and +86d15`25.6 .

Proper Motion of 2 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 -11.54 ± 0.13 miliarcseconds/year towards the north and 80.65 ± 0.15 miliarcseconds/year east if we saw them in the horizon.

2 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 70.0000000 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 2 Ursae Minoris

2 Ursae Minoris has a spectral type of K2II-III. This means the star is a orange to red giant star. The star is 7444.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24279.5993273600000000s. The star has a B-V Colour Index of 1.2 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,489 Kelvin.

2 Ursae Minoris Radius has been calculated as being 21.02 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 14,624,977.18.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 18.82. 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 0.12 with an error value of 0.04 Fe/H with the Sun has a value of 1 to put it into context.

2 Ursae Minoris Apparent and Absolute Magnitudes

2 Ursae Minoris has an apparent magnitude of 4.24 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 -0.67 If you used the 2007 Parallax value, you would get an absolute magnitude of -0.43. 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 2 Ursae Minoris

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 10.43 which gave the calculated distance to 2 Ursae Minoris as 312.72 light years away from Earth or 95.88 parsecs. It would take a spaceship travelling at the speed of light, 312.72 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 11.64 which put 2 Ursae Minoris at a distance of 280.21 light years or 85.91 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 7,444.00 Parsecs or 24,279.60 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

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.

2 Ursae Minoris Facts

Alternative Names

Traditional/Proper Name2 Ursae Minoris
Flamsteed Name2 Cephei
Flamsteed Short Name2 Cep
Hipparcos Library I.D.5372
Bonner DurchmusterungBD+85 19
Henry Draper Designation5848

Visual Facts

Star Typegiant star
Absolute Magnitude-0.67 / -0.43
Visual / Apparent Magnitude4.24
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)01h 08m 44.16
Declination (Dec.)+86d15`25.6
Galactic Latitude23.40 degrees
Galactic Longitude123.24 degrees
1997 Distance from Earth10.43 Parallax (milliarcseconds)
 312.72 Light Years
 95.88 Parsecs
2007 Revised Distance from Earth11.64 Parallax (milliarcseconds)
 280.21 Light Years
 85.91 Parsecs
Galacto-Centric Distance24,279.60 Light Years / 7,444.00 Parsecs
Proper Motion Dec.-11.54 ± 0.13 milliarcseconds/year
Proper Motion RA.80.65 ± 0.15 milliarcseconds/year
B-V Index1.20
Radial Velocity8.38 ± 0.19 km/s
Iron Abundance0.12 ± 0.04 Fe/H
Spectral TypeK2II-III
Colour(K) Orange to Red

Estimated Facts

Luminosity (x the Sun)70.0000000
Calculated Effective Temperature4,489 Kelvin

Sources and Links

SIMBAD SourceLink

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