Rho Cassiopeiae is a blue to white pulsating supergiant star that can be located in the constellation of Cassiopeia. The description is based on the spectral class. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.
Rho Cassiopeiae (Rho Cas) is the Bayer Classification for the star. The Id of the star in the Yale Bright Star Catalogue is HR9045. HIP117863 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD224014.
Rho Cassiopeiae has alternative name(s) :- , rho Cas.
Flamsteed designations are named after the creator, Sir John Flamsteed. Sir John numbered the stars in the constellation with a number and the latin name, this star's Flamsteed designation is 7 Cassiopeiae with it shortened to 7 Cas.
BD number is the number that the star was filed under in the Durchmusterung or Bonner Durchmusterung, a star catalogue that was put together by the Bonn Observatory between 1859 to 1903. The star's BD Number is BD+56 3111.
More details on star alternative names can be found at Star Names .
The location of the star in the night sky 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 Rho Cassiopeiae, the location is 23h 54m 23.04 and +57° 29` 57.8 .
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 -3.73 ± 0.15 miliarcseconds/year towards the north and -4.48 ± 0.21 miliarcseconds/year east if we saw them in the horizon. The Radial Velocity, that is the speed at which the star is moving away/towards us is -54.30000 km/s with an error of about 0.40 km/s .
Rho Cassiopeiae has a spectral type of F8Iavar. This means the star is a blue to white supergiant star. The star has a B-V Colour Index of 1.19 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,586 Kelvin.
Rho Cassiopeiae Radius has been calculated as being 660.87 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 459,833,623.43.km. If you need the diameter of the star, you just need to multiple the radius by 2. 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 0.05 with an error value of 9.99 Fe/H with the Sun has a value of 1 to put it into context.
Rho Cassiopeiae has an apparent magnitude of 4.51 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. Using the supplied Parallax value, you would get an absolute magnitude of -8.25 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 0.28 which gave the calculated distance to Rho Cassiopeiae as 11648.69 light years away from Earth or 3571.43 parsecs. It would take a spaceship travelling at the speed of light, 11648.69 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 Semiregular giants and supergiants of F, G, or K spectral s, sometimes with emission lines in their 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. Rho Cassiopeiae brightness ranges from a magnitude of 4.755 to a magnitude of 4.574 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.2 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 Metallicity and/or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.
|Primary / Proper / Traditional Name||Rho Cassiopeiae|
|Alternative Names||Rho Cas, HD 224014, HIP 117863, HR 9045, 7 Cassiopeiae, 7 Cas, BD+56 3111, rho Cas|
|Multiple Star System||No / Unknown|
|Star Type||very luminous Supergiant Star|
|Colour||blue to white|
|Visual / Apparent Magnitude||4.51|
|Naked Eye Visible||Yes - Magnitudes|
|Right Ascension (R.A.)||23h 54m 23.04|
|Declination (Dec.)||+57° 29` 57.8|
|Galactic Latitude||-4.52 degrees|
|Galactic Longitude||115.30 degrees|
|Distance from Earth||0.28 Parallax (milliarcseconds)|
|11648.69 Light Years|
|Proper Motion Dec.||-3.73 ± 0.15 milliarcseconds/year|
|Proper Motion RA.||-4.48 ± 0.21 milliarcseconds/year|
|Radial Velocity||-54.30 ± 0.40 km/s|
|Iron Abundance||0.05 ± 9.99 Fe/H|
|Variable Star Class||Pulsating|
|Variable Star Type||Semiregular giants and supergiants of F, G, or K spectral s, sometimes with emission lines in their spectral|
|Mean Variability Period in Days||0.172|
|Variable Magnitude Range (Brighter - Dimmer)||4.574 - 4.755|
|Calculated Effective Temperature||4,586 Kelvin|