Alula Australis (Xi Ursae Majoris) is a white to yellow main sequence dwarf star that can be located in the constellation of Ursa Major. The description is based on the spectral class. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.
Xi Ursae Majoris (Ksi Uma) is the Bayer Classification for the star. The Id of the star in the Yale Bright Star Catalogue is HR4374. HIP55203 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD98230. The Gliese ID of the star is GL 423A. The star was part of the original catalogue devised by German Astronomer Wilheim Gliese of stars located within 20 parsecs of Earth. Star Names
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 53 Ursae Majoris with it shortened to 53 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+32 2132.
More details on star alternative names can be found at Star Names .
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 Alula Australis, the location is 11h 18m 11.24 and +31° 31` 50.8 .
Alula Australis has a spectral type of G0V. This means the star is a white to yellow main sequence dwarf star. The star has a B-V Colour Index of 0.6 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,895 Kelvin.
Alula Australis has an apparent magnitude of 3.79 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. 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.
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.
|Primary / Proper / Traditional Name||Alula Australis|
|Alternative Names||Xi Ursae Majoris, Ksi Uma, HD 98230, HIP 55203, HR 4374, 53 Ursae Majoris, 53 UMa, BD+32 2132, Gliese 423A|
|Multiple Star System||Yes|
|Star Type||main sequence Dwarf Star|
|Colour||white to yellow|
|Visual / Apparent Magnitude||3.79|
|Naked Eye Visible||Yes - Magnitudes|
|Right Ascension (R.A.)||11h 18m 11.24|
|Declination (Dec.)||+31° 31` 50.8|
|Calculated Effective Temperature||5,895 Kelvin|
The star has been identified as being a multi-star system, one in which there is at least one star in close orbit to another star or two or more stars orbiting a central point. The stars may be of equal mass, unequal mass where one star is stronger than the other or be in groups orbiting a central point which doesn't necessarily have to be a star. More information can be found on my dedicated multiple star systems page. The source of the info is Simbad. The file is dated 2000 so any differences between this and any other source will be down to the actual source from where the information came from.
|Proper Motion mas/yr|
|H.D. Id||B.D. Id||Star Code||Magnitude||R.A.||Dec.||Spectrum||Colour||Year|