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VY Arietis - HD17433 - HIP13118

VY Arietis is a orange to red rotating star that can be located in the constellation of Aries. HIP13118 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD17433. VY Arietis has alternative name(s), VY_Ari.

Location of VY Arietis

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 VY Arietis, the location is 02h 48m 43.58 and +31d06`56.2 .

Proper Motion of VY Arietis

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 -173.83 ± 000.33 towards the north and 212.10 ± 000.69 east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of VY Arietis

VY Arietis has a spectral type of K0. This means the star is a orange to red star. The star has a B-V Colour Index of 0.95 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,082 Kelvin.

VY Arietis has been calculated as 2.17 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,511,060.97.km.

VY Arietis Apparent and Absolute Magnitudes

VY Arietis has an apparent magnitude of 6.94 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 3.72 If you used the 2007 Parallax value, you would get an absolute magnitude of 3.83. 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 VY Arietis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 22.73 which gave the calculated distance to VY Arietis as 143.49 light years away from Earth or 43.99 parsecs. It would take a spaceship travelling at the speed of light, 143.49 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 23.89 which put VY Arietis at a distance of 136.53 light years or 41.86 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.

Variable Type of VY Arietis

The star is a rotating BY Draconis 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. VY Arietis brightness ranges from a magnitude of 7.000 to a magnitude of 7.000 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 17.0 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 Stellar Age, Metallicity or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

VY Arietis Facts

Alternative Names

Traditional NameVY Arietis
Short NameVY Ari
Hipparcos Library I.D.13118
Bonner DurchmusterungBD+30 448
Henry Draper Designation17433

Visual Facts

Star Type star
Absolute Magnitude3.72 / 3.83
Apparent Magnitude6.94
Right Ascension (R.A.)02h 48m 43.58
Declination (Dec.)+31d06`56.2
1997 Distance from Earth22.73 Parallax (milliarcseconds)
 143.49 Light Years
 43.99 Parsecs
2007 Revised Distance from Earth23.89 Parallax (milliarcseconds)
 136.53 Light Years
 41.86 Parsecs
Proper Motion Dec.-173.83 ± 0.33 milliarcseconds/year
Proper Motion RA.212.10 ± 0.69 milliarcseconds/year
B-V Index0.95
Spectral TypeK0
Colour(K) Orange to Red

Variable Star Details

Variable Star ClassRotating
Variable Star TypeBY Draconis
Mean Variability Period in Days17.000

Estimated Facts

Radius (x the Sun)2.17
Calculated Effective Temperature5,082 Kelvin

Sources and Links

SIMBAD SourceLink

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