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OU Andromedae, HD223460, HIP117503

OU Andromedae is a white to yellow rotating giant star that can be located in the constellation of Andromeda. OU Andromedae is the brightest star in Andromeda 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.

HIP117503 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD223460.

OU Andromedae has alternative name(s), OU And.

Location of OU Andromedae

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 OU Andromedae, the location is 23h 49m 40.96 and +36d25`31.4 .

Proper Motion of OU Andromedae

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 -47.59 ± 0.20 miliarcseconds/year towards the north and 1.01 ± 0.34 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of OU Andromedae

OU Andromedae has a spectral type of G1IIIe. This means the star is a white to yellow giant star. The star is 7440.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24266.5527936000000000s. The star has a B-V Colour Index of 0.8 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,286 Kelvin.

OU Andromedae Radius has been calculated as being 10.11 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 7,032,851.56.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 9.70. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures. The star's Iron Abundance is -0.17 with an error value of 9.99 Fe/H with the Sun has a value of 1 to put it into context.

OU Andromedae Apparent and Absolute Magnitudes

OU Andromedae has an apparent magnitude of 5.86 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 0.21 If you used the 2007 Parallax value, you would get an absolute magnitude of 0.30. 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 OU Andromedae

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 7.41 which gave the calculated distance to OU Andromedae as 440.17 light years away from Earth or 134.95 parsecs. It would take a spaceship travelling at the speed of light, 440.17 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 7.71 which put OU Andromedae at a distance of 423.04 light years or 129.70 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 7,440.00 Parsecs or 24,266.55 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 OU Andromedae

The star is a rotating FK Comae Berenices 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. OU Andromedae brightness ranges from a magnitude of 6.031 to a magnitude of 5.999 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.

OU Andromedae Facts

Alternative Names

Traditional/Proper NameOU Andromedae
Short NameOU And
Hipparcos Library I.D.117503
Bonner DurchmusterungBD+35 5110
Henry Draper Designation223460

Visual Facts

Star Typegiant star
Absolute Magnitude0.21 / 0.30
Visual / Apparent Magnitude5.86
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)23h 49m 40.96
Declination (Dec.)+36d25`31.4
Galactic Latitude-24.80 degrees
Galactic Longitude109.28 degrees
1997 Distance from Earth7.41 Parallax (milliarcseconds)
 440.17 Light Years
 134.95 Parsecs
2007 Revised Distance from Earth7.71 Parallax (milliarcseconds)
 423.04 Light Years
 129.70 Parsecs
Galacto-Centric Distance24,266.55 Light Years / 7,440.00 Parsecs
Proper Motion Dec.-47.59 ± 0.20 milliarcseconds/year
Proper Motion RA.1.01 ± 0.34 milliarcseconds/year
B-V Index0.80
Radial Velocity-1.60 ± 0.40 km/s
Iron Abundance-0.17 ± 9.99 Fe/H
Spectral TypeG1IIIe
Colour(G) White to Yellow

Variable Star Details

Variable Star ClassRotating
Variable Star TypeFK Comae Berenices
Mean Variability Period in Days0.032
Variable Magnitude Range (Brighter - Dimmer)5.999 - 6.031

Estimated Facts

Calculated Effective Temperature5,286 Kelvin

Sources and Links

SIMBAD SourceLink

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