Plasketts Star is a blue pulsating star that can be located in the constellation of Monoceros. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.
HIP31646 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD47129.
Plasketts Star has alternative name(s), V640_Mon.
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 Plasketts Star, the location is 06h 37m 24.04 and +06d08`07.4 .
Plasketts Star has a spectral type of O8e. This means the star is a blue star. The star has a B-V Colour Index of 0.01 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 10,051 Kelvin. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.
Plasketts Star has an apparent magnitude of 6.05 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 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 -0.74 which gave the calculated distance to Plasketts Star as -4407.61 light years away from Earth or -1351.35 parsecs. It would take a spaceship travelling at the speed of light, -4407.61 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 Semi-Regular Star which are giants or supergiants of intermediate and late spectral 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. Plasketts Star brightness ranges from a magnitude of 6.000 to a magnitude of 6.000 over its variable period. The smaller the magnitude, the brighter the star.
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.
|Traditional/Proper Name||Plasketts Star|
|Short Name||V640 Mon|
|Hipparcos Library I.D.||31646|
|Bonner Durchmusterung||BDD+06 1309|
|Henry Draper Designation||47129|
|Visual / Apparent Magnitude||6.05|
|Naked Eye Visible||Yes - Ref: Wiki|
|Right Ascension (R.A.)||06h 37m 24.04|
|Galactic Latitude||-0.31 degrees|
|Galactic Longitude||205.87 degrees|
|1997 Distance from Earth||-0.74 Parallax (milliarcseconds)|
|-4407.61 Light Years|
|Radial Velocity||23.50 ± 1.80 km/s|
|Variable Star Class||Pulsating|
|Variable Star Type||Semi-Regular Star which are giants or supergiants of intermediate and late spectral|
|Calculated Effective Temperature||10,051 Kelvin|