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72 Ursae Majoris, HD108346, HIP60712

72 Ursae Majoris is a blue star that can be located in the constellation of Ursa Major. The description is based on the spectral class. The star can not be seen by the naked eye, you need a telescope to see it.

72 Ursae Majoris's Alternative Names

HIP60712 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD108346.

Flamsteed designations are named after the creator, Sir John Flamsteed. Sir John numbered the stars in the constellation with a number and the latin name, this star's Flamsteed designation is 72 Ursae Majoris with it shortened to 72 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+55 1533.

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

Location of 72 Ursae Majoris

The location of the 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 star is compared to the celestial equator and is expressed in degrees. For 72 Ursae Majoris, the location is 12h 26m 32.60 and +55° 09` 33.9 .

Proper Motion of 72 Ursae Majoris

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 10.92 ± 0.39 miliarcseconds/year towards the north and 12.73 ± 0.57 miliarcseconds/year east if we saw them in the horizon. The Radial Velocity, that is the speed at which the star is moving away/towards us is 15.00000 km/s with an error of about 19.70 km/s .

72 Ursae Majoris 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 21.59 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.

Physical Properties (Colour, Temperature) of 72 Ursae Majoris

72 Ursae Majoris has a spectral type of Am. This means the star is a blue star. The star is 7,441.00 Parsecs from the Galactic Centre or terms of Light Years is 24,269.81 s. The star has a B-V Colour Index of 0.1 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 8,434 Kelvin.

72 Ursae Majoris Radius has been calculated as being 2.49 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,735,036.68.km. If you need the diameter of the star, you just need to multiple the radius by 2. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 2.21. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

72 Ursae Majoris Apparent and Absolute Magnitudes

72 Ursae Majoris has an apparent magnitude of 7.03 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 1.22 If you used the 2007 Parallax value, you would get an absolute magnitude of 1.48. 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 72 Ursae Majoris

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 6.90 which gave the calculated distance to 72 Ursae Majoris as 472.70 light years away from Earth or 144.93 parsecs. It would take a spaceship travelling at the speed of light, 472.70 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 7.75 which put 72 Ursae Majoris at a distance of 420.86 light years or 129.03 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 7,441.00 Parsecs or 24,269.81 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.

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72 Ursae Majoris Facts

Visual Facts

Primary / Proper / Traditional Name72 Ursae Majoris
Alternative NamesHD 108346, HIP 60712, 72 UMa, BD+55 1533
Spectral TypeAm
Multiple Star SystemNo / Unknown
Star TypeStar
Colour blue
GalaxyMilky Way
ConstellationUrsa Major
Absolute Magnitude1.22 / 1.48
Visual / Apparent Magnitude7.03
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)12h 26m 32.60
Declination (Dec.)+55° 09` 33.9
Galactic Latitude61.61 degrees
Galactic Longitude130.42 degrees
1997 Distance from Earth6.90 Parallax (milliarcseconds)
 472.70 Light Years
 144.93 Parsecs
2007 Distance from Earth7.75 Parallax (milliarcseconds)
 420.86 Light Years
 129.03 Parsecs
Galacto-Centric Distance24,269.81 Light Years / 7,441.00 Parsecs
Proper Motion Dec.10.92 ± 0.39 milliarcseconds/year
Proper Motion RA.12.73 ± 0.57 milliarcseconds/year
B-V Index0.10
Radial Velocity15.00 ± 19.70 km/s
Semi-Major Axis10282.00
Stellar Luminosity (Lsun)21.59

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Estimated Facts

Calculated Effective Temperature8,434 Kelvin

Sources and Links

SIMBAD SourceLink

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