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Tania Australis, Mu Ursae Majoris, 34 Ursae Majoris, HD89758, HIP50801, HR4069

Tania Australis (Mu Ursae Majoris) is a red pulsating giant star that can be located in the constellation of UrsaMajor. Tania Australis is the brightest star in Ursa Major 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. It is calculated at being 4.604 Billion Years old. This information comes from ExoPlanet.

Mu Ursae Majoris is the Bayer Classification for the star. The Id of the star in the Yale Bright Star Catalogue is HR4069. HIP50801 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD89758.

Tania Australis has alternative name(s), NSV 04829. In Arabic, it is known as Ath-Thaniyah.

Location of Tania Australis

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 Tania Australis, the location is 10h 22m 19.80 and +41d29`58.0 .

Proper Motion of Tania Australis

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 35.34 ± 0.34 miliarcseconds/year towards the north and -81.47 ± 0.54 miliarcseconds/year east if we saw them in the horizon.

Tania Australis 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 15.0000000 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, Age, Mass, Radius) of Tania Australis

Tania Australis has a spectral type of M0III SB. This means the star is a red giant star. The star is 7439.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24263.2911601600000000s. The star has a B-V Colour Index of 1.6 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 3,779 Kelvin.

Tania Australis Radius has been calculated as being 40.57 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 28,225,867.60.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 37.51. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures. The star's solar mass is 1.23 times that of the Sun's. The Sun's Mass is 1,989,100,000,000,000,000,000 billion kg. which to calculate using this website is too large. To give idea of size, the Sun is 99.86% the mass of the solar system.

The star's metallicity is -0.250000, this value is the fractional amount of the star that is not Hydrogen (X) or Helium (Y). An older star would have a high metallicity whereas a new star would have a lower one.

The star is believed to be about 4.60 Billion years old. To put in context, the Sun is believed to be about five billion years old and the Universe is about 13.8 billion years old.

Tania Australis Apparent and Absolute Magnitudes

Tania Australis has an apparent magnitude of 3.06 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 -1.35 If you used the 2007 Parallax value, you would get an absolute magnitude of -1.18. 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 Tania Australis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 13.11 which gave the calculated distance to Tania Australis as 248.79 light years away from Earth or 76.28 parsecs. It would take a spaceship travelling at the speed of light, 248.79 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 14.16 which put Tania Australis at a distance of 230.34 light years or 70.62 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 7,439.00 Parsecs or 24,263.29 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

Variable Type of Tania Australis

The star is a pulsating Semi-Regular Star which are giants or supergiants of intermediate and late spectral 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. Tania Australis brightness ranges from a magnitude of 3.186 to a magnitude of 3.123 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.0 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.

Tania Australis Facts

Alternative Names

Traditional/Proper NameTania Australis
Flamsteed Name34 Ursae Majoris
Flamsteed Short Name34 UMa
Short NameNSV 04829
Arabic NameAth-Thaniyah
English MeaningThe southern one of 'the second' leap
Bayer DesignationMu Ursae Majoris
Hipparcos Library I.D.50801
Yale Bright Star Catalogue (HR) Id4069
Bonner DurchmusterungBD+42 2115
Henry Draper Designation89758

Visual Facts

Star Typegiant star
Age4.60 Billion Years Old
Absolute Magnitude-1.35 / -1.18
Visual / Apparent Magnitude3.06
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)10h 22m 19.80
Declination (Dec.)+41d29`58.0
Galactic Latitude56.36 degrees
Galactic Longitude177.90 degrees
1997 Distance from Earth13.11 Parallax (milliarcseconds)
 248.79 Light Years
 76.28 Parsecs
2007 Revised Distance from Earth14.16 Parallax (milliarcseconds)
 230.34 Light Years
 70.62 Parsecs
Galacto-Centric Distance24,263.29 Light Years / 7,439.00 Parsecs
Proper Motion Dec.35.34 ± 0.34 milliarcseconds/year
Proper Motion RA.-81.47 ± 0.54 milliarcseconds/year
B-V Index1.60
Radial Velocity-22.15 ± 3.58 km/s
Iron Abundance-0.04 ± 9.99 Fe/H
Spectral TypeM0III SB
Colour(M) Red

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeSemi-Regular Star which are giants or supergiants of intermediate and late spectral
Mean Variability Period in Days0.048
Variable Magnitude Range (Brighter - Dimmer)3.123 - 3.186

Estimated Facts

Luminosity (x the Sun)15.0000000
Calculated Effective Temperature3,779 Kelvin
Mass Compared to the Sun1.23
Metallicity-0.25000

Sources and Links

SIMBAD SourceLink

Related Stars

Location of Tania Australis in Ursa Major


Tania Australis (Mu Ursae Majoris) Location in Ursa Major

The map was generated using Night Vision, an awesome free application by Brian Simpson.


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