Universe Guide

71 Ursae Majoris

71 Ursae Majoris Facts

71 Ursae Majoris's Alternative Names

The Id of the star in the Yale Bright Star Catalogue is HR4726. HIP60584 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD108135.

Flamsteed designations are named after the creator, Sir John Flamsteed. Sir John named the stars in the constellation with a number and its latin name, this star's Flamsteed designation is 71 Ursae Majoris. The Flamsteed name can be shortened to 71 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+57 1373.

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

Location of 71 Ursae Majoris

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 71 Ursae Majoris, the location is 12h 25m 03.22 and +56° 46` 40.3 .

Radial Velocity and Proper Motion of 71 Ursae Majoris

Proper Motion

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 -12.80 ± 0.24 milliarcseconds/year towards the north and -14.29 ± 0.33 milliarcseconds/year east if we saw them in the horizon.

Radial Velocity

The Radial Velocity, that is the speed at which the star is moving away/towards the Sun is -15.66 km/s with an error of about 0.40 km/s . When the value is negative then the star and the Sun are getting closer to one another, likewise, a positive number means that two stars are moving away. Its nothing to fear as the stars are so far apart, they won't collide in our life-time, if ever.

Physical Properties (Colour, Temperature) of 71 Ursae Majoris

71 Ursae Majoris Colour and Temperature

71 Ursae Majoris has a spectral type of M3III. This means the star is a red giant star. The star has a B-V Colour Index of 1.62 which means the star's temperature is about 3,728 Kelvin. The temperature was calculated using information from Morgans @ Uni.edu at being .

71 Ursae Majoris Radius

Radius has been calculated as being 55.97 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 38,945,345.39.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 40.36. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

71 Ursae Majoris Apparent and Absolute Magnitudes

71 Ursae Majoris has an apparent magnitude of 5.82 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 -1.99 If you used the 2007 Parallax value, you would get an absolute magnitude of -1.28. 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 71 Ursae Majoris

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 2.74 which gave the calculated distance to 71 Ursae Majoris as 1190.38 light years away from Earth or 364.96 parsecs. If you want that in miles, it is 798,288,622,829.

In 2007, Hipparcos data was revised with a new parallax of 3.80 which put 71 Ursae Majoris at a distance of 858.32 light years or 263.16 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.

Using the 2007 distance, the star is roughly 54,280,268.18 Astronomical Units from the Earth/Sun give or take a few. An Astronomical Unit is the distance between Earth and the Sun. The number of A.U. is the number of times that the star is from the Earth compared to the Sun.

The star's Galacto-Centric Distance is 7,488.00 Parsecs or 24,423.11 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

Travel Time to 71 Ursae Majoris

The time it will take to travel to this star is dependent on how fast you are going. U.G. has done some calculations as to how long it will take going at differing speeds. A note about the calculations, when I'm talking about years, I'm talking non-leap years only (365 days).

The New Horizons space probe is the fastest probe that we've sent into space at the time of writing. Its primary mission was to visit Pluto which at the time of launch (2006), Pluto was still a planet.

DescriptionSpeed (m.p.h.)Time (years)
Airbus A380736782,070,197.02
Speed of Sound (Mach 1)767.269750,197,994.45
Concorde (Mach 2)1,534.54375,098,508.35
New Horizons Probe33,00017,442,535.30
Speed of Light670,616,629.00858.32

Variable Type of 71 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. 71 Ursae Majoris brightness ranges from a magnitude of 5.916 to a magnitude of 5.838 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.1 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.

Hide Explanations
Show GridLines

Additional 71 Ursae Majoris Facts and Figures

Visual Facts

Primary / Proper / Traditional Name71 Ursae Majoris
Alternative NamesHD 108135, HIP 60584, HR 4726, 71 Uma, BD+57 1373
Spectral TypeM3III
Constellation's Main StarNo
Multiple Star SystemNo / Unknown
Star TypeGiant Star
GalaxyMilky Way
ConstellationUrsa Major
Absolute Magnitude -1.99 / -1.28
Visual / Apparent Magnitude5.82
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)12h 25m 03.22
Declination (Dec.)+56° 46` 40.3
Galactic Latitude59.98 degrees
Galactic Longitude130.16 degrees
1997 Distance from Earth2.74 Parallax (milliarcseconds)
 1190.38 Light Years
 364.96 Parsecs
2007 Distance from Earth3.80 Parallax (milliarcseconds)
 858.32 Light Years
 263.16 Parsecs
 54,280,268.18 Astronomical Units
Galacto-Centric Distance24,423.11 Light Years / 7,488.00 Parsecs
Proper Motion Dec. -12.80 ± 0.24 milliarcseconds/year
Proper Motion RA.-14.29 ± 0.33 milliarcseconds/year
B-V Index1.62
Radial Velocity-15.66 ± 0.40 km/s
Semi-Major Axis6757.00

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Variable Star Details

Variable Star ClassEruptive
Variable Star TypeIrregular
Mean Variability Period in Days0.065
Variable Magnitude Range (Brighter - Dimmer)5.838 - 5.916

Estimated Calculated Facts

Radius (x the Sun)40.36
Effective Temperature3,728 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Comments and Questions

There's no register feature and no need to give an email address if you don't need to. All messages will be reviewed before being displayed. Comments may be merged or altered slightly such as if an email address is given in the main body of the comment.

You can decline to give a name which if that is the case, the comment will be attributed to a random star. A name is preferred even if its a random made up one by yourself.

This website is using cookies. More info. That's Fine