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WX Cephei, HD213631, HIP111166

WX Cephei is a blue eclipsing star that can be located in the constellation of Cepheus. The star can not be seen by the naked eye, you need a telescope to see it.

HIP111166 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD213631.

WX Cephei has alternative name(s), WX Cep.

Location of WX Cephei

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 WX Cephei, the location is 22h 31m 15.78 and +63d31`21.5 .

Proper Motion of WX Cephei

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 2.21 ± 0.97 miliarcseconds/year towards the north and 5.40 ± 1.13 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of WX Cephei

WX Cephei has a spectral type of A2 + A5:. This means the star is a blue star. The star has a B-V Colour Index of 0.39 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 6,431 Kelvin.

WX Cephei Radius has been calculated as being 9.51 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 6,619,662.05.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 5.71. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

WX Cephei Apparent and Absolute Magnitudes

WX Cephei has an apparent magnitude of 8.95 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 -0.51 If you used the 2007 Parallax value, you would get an absolute magnitude of 0.60. 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 WX Cephei

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 1.28 which gave the calculated distance to WX Cephei as 2548.15 light years away from Earth or 781.25 parsecs. It would take a spaceship travelling at the speed of light, 2548.15 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 2.14 which put WX Cephei at a distance of 1524.13 light years or 467.29 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 WX Cephei

The star is a eclipsing Beta Persei (Algol)/Detached Main Sequence (subtype) 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. WX Cephei brightness ranges from a magnitude of 9.620 to a magnitude of 9.030 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 3.4 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.

WX Cephei Facts

Alternative Names

Traditional/Proper NameWX Cephei
Short NameWX Cep
Hipparcos Library I.D.111166
Bonner DurchmusterungBD+62 2091
Henry Draper Designation213631

Visual Facts

Star Type star
Absolute Magnitude-0.51 / 0.60
Visual / Apparent Magnitude8.95
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)22h 31m 15.78
Declination (Dec.)+63d31`21.5
Galactic Latitude4.78 degrees
Galactic Longitude108.05 degrees
1997 Distance from Earth1.28 Parallax (milliarcseconds)
 2548.15 Light Years
 781.25 Parsecs
2007 Revised Distance from Earth2.14 Parallax (milliarcseconds)
 1524.13 Light Years
 467.29 Parsecs
Proper Motion Dec.2.21 ± 0.97 milliarcseconds/year
Proper Motion RA.5.40 ± 1.13 milliarcseconds/year
B-V Index0.39
Radial Velocity-6.70 ± 4.60 km/s
Spectral TypeA2 + A5:
Colour(A) blue

Variable Star Details

Variable Star ClassEclipsing
Variable Star TypeBeta Persei (Algol)/Detached Main Sequence (subtype)
Mean Variability Period in Days3.378
Variable Magnitude Range (Brighter - Dimmer)9.030 - 9.620

Estimated Facts

Calculated Effective Temperature6,431 Kelvin

Sources and Links

SIMBAD SourceLink

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