Universe Guide

GR Ursae Majoris

GR Ursae Majoris Facts

GR Ursae Majoris's Alternative Names

HIP51110 is the reference name for the star in the Hipparcos Star Catalogue.

GR Ursae Majoris has alternative name(s) :- , GR UMa.

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+63 899.

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

Location of GR Ursae Majoris

The location of the variable 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 GR Ursae Majoris, the location is 10h 26m 31.56 and +62° 20` 47.6 .

Physical Properties (Colour, Temperature) of GR Ursae Majoris

GR Ursae Majoris Colour and Temperature

GR Ursae Majoris has a spectral type of M8. This means the star is a red variable star. The star has a B-V Colour Index of 1.22 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,531 Kelvin.

GR Ursae Majoris Radius

Radius has been calculated as being 31.95 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 22,233,898.07.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.

GR Ursae Majoris Apparent and Absolute Magnitudes

GR Ursae Majoris has an apparent magnitude of 10.85 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 -1.62 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 GR Ursae Majoris

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 0.32 which gave the calculated distance to GR Ursae Majoris as 10192.60 light years away from Earth or 3125 parsecs. It would take a spaceship travelling at the speed of light, 10192.60 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.

Variable Type of GR Ursae Majoris

The star is a eruptive Irregular 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. GR Ursae Majoris brightness ranges from a magnitude of 9.935 to a magnitude of 9.357 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.5 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 GR Ursae Majoris Facts and Figures

Visual Facts

Primary / Proper / Traditional NameGR Ursae Majoris
Alternative NamesHIP 51110, BD+63 899, GR UMa
Spectral TypeM8
Constellation's Main StarNo
Multiple Star SystemNo / Unknown
Star TypeVariable Star
GalaxyMilky Way
ConstellationUrsa Major
Absolute Magnitude -1.62
Visual / Apparent Magnitude10.85
Naked Eye VisibleRequires a 4.5 - 6 Inch Telescope - Magnitudes
Right Ascension (R.A.)10h 26m 31.56
Declination (Dec.)+62° 20` 47.6
Galactic Latitude47.49 degrees
Galactic Longitude146.88 degrees
Distance from Earth0.32 Parallax (milliarcseconds)
 10192.60 Light Years
 3125 Parsecs
 644,573,028.07 Astronomical Units
B-V Index1.22

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Variable Star Details

Variable Star ClassEruptive
Variable Star TypeIrregular
Mean Variability Period in Days0.543
Variable Magnitude Range (Brighter - Dimmer)9.357 - 9.935

Estimated Calculated Facts

Radius (x the Sun)31.95
Effective Temperature4,531 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Comments and Questions

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