W Geminorum is a blue to white pulsating star that can be located in the constellation of Gemini. HIP31404 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD46595. W Geminorum has alternative name(s), W_Gem.
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 W Geminorum, the location is 06h 34m 57.45 and +15d19`49.7 .
W Geminorum has a spectral type of F7.5. This means the star is a blue to white star. The star has a B-V Colour Index of 0.94 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,105 Kelvin.
W Geminorum has been calculated as 53.82 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 37,447,983.84.km.
W Geminorum has an apparent magnitude of 7.06 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 -3.27 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.
Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 0.86 which gave the calculated distance to W Geminorum as 3792.60 light years away from Earth or 1162.79 parsecs. It would take a spaceship travelling at the speed of light, 3792.60 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.
The star is a pulsating Delta Cepheid 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. W Geminorum brightness ranges from a magnitude of 8.000 to a magnitude of 7.000 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 8.0 days (variability).
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.
|Traditional Name||W Geminorum|
|Short Name||W Gem|
|Hipparcos Library I.D.||31404|
|Bonner Durchmusterung||BD+15 1246|
|Henry Draper Designation||46595|
|Right Ascension (R.A.)||06h 34m 57.45|
|1997 Distance from Earth||0.86 Parallax (milliarcseconds)|
|3792.60 Light Years|
|Colour||(F) blue to white|
|Variable Star Class||Pulsating|
|Variable Star Type||Delta Cepheid|
|Mean Variability Period in Days||8.000|
|Variable Magnitude Range (Brighter - Dimmer)||7.000 - 8.000|
|Radius (x the Sun)||53.82|
|Calculated Effective Temperature||5,105 Kelvin|