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R Ursae Minoris

R Ursae Minoris Facts

R Ursae Minoris's Alternative Names

HIP80802 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD149683.

R Ursae Minoris has alternative name(s) :- R UMi, R UMi.

BD number is the number that the star was filed under in the Durchmusterung or Bonner Durchmusterung, a star catalogue that was put together by the Bonn Observatory between 1859 to 1903. The star's BD Number is BD+72 732a.

More details on objects' alternative names can be found at Star Names .

Location of R Ursae Minoris

The location of the giant star in the night sky 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 object is compared to the celestial equator and is expressed in degrees. For R Ursae Minoris, the location is 16h 29m 57.87 and +72° 16` 49.0 .

Physical Properties (Colour, Temperature) of R Ursae Minoris

R Ursae Minoris Colour and Temperature

R Ursae Minoris has a spectral type of M7IIIe. This means the star is a red giant star. The star has a B-V Colour Index of 1.14 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,593 Kelvin.

R Ursae Minoris Radius

Radius has been calculated as being 10.49 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 7,297,728.03.km. If you need the diameter of the star, you just need to multiple the radius by 2. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

R Ursae Minoris Apparent and Absolute Magnitudes

R Ursae Minoris has an apparent magnitude of 9.48 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. Using the supplied Parallax value, you would get an absolute magnitude of 0.74 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 R Ursae Minoris

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 1.79 which gave the calculated distance to R Ursae Minoris as 1822.14 light years away from Earth or 558.66 parsecs. It would take a spaceship travelling at the speed of light, 1822.14 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.

Variable Type of R Ursae Minoris

The star is a pulsating Semiregular late- (M variable type which means that its size changes over time. The Variable Type is usually named after the first star of that type to be spotted. R Ursae Minoris brightness ranges from a magnitude of 9.013 to a magnitude of 8.137 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 331.0 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.

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Additional R Ursae Minoris Facts and Figures

Visual Facts

Primary / Proper / Traditional NameR Ursae Minoris
Alternative NamesR UMi, HD 149683, HIP 80802, BD+72 732a, R UMi
Spectral TypeM7IIIe
Constellation's Main StarNo
Multiple Star SystemNo / Unknown
Star TypeGiant Star
GalaxyMilky Way
ConstellationUrsa Minor
Absolute Magnitude 0.74
Visual / Apparent Magnitude9.48
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)16h 29m 57.87
Declination (Dec.)+72° 16` 49.0
Galactic Latitude36.24 degrees
Galactic Longitude105.01 degrees
Distance from Earth1.79 Parallax (milliarcseconds)
 1822.14 Light Years
 558.66 Parsecs
 115,231,093.72 Astronomical Units
B-V Index1.14
Radial Velocity-22.00 ± 4.60 km/s

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeSemiregular late- (M
Mean Variability Period in Days331.000
Variable Magnitude Range (Brighter - Dimmer)8.137 - 9.013

Estimated Calculated Facts

Radius (x the Sun)10.49
Effective Temperature4,593 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Comments and Questions

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