X Coronae Borealis is a red pulsating variable star that can be located in the constellation of Corona Borealis. The description is based on the spectral class. X Coronae Borealis is not part of the constellation but is within the borders of the constellation.
The star can not be seen by the naked eye, you need a telescope to see it.
HIP77460 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD141678.
X Coronae Borealis has alternative name(s) :- , X CrB.
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 X Coronae Borealis, the location is 15h 48m 53.53 and +36° 14` 52.6 .
X Coronae Borealis has a spectral type of M5e-M7e. This means the star is a red variable star. The star has a B-V Colour Index of 1.03 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,908 Kelvin.
X Coronae Borealis Radius has been calculated as being 10.40 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 7,237,258.88.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.
X Coronae Borealis has an apparent magnitude of 11.04 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 0.47 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 0.77 which gave the calculated distance to X Coronae Borealis as 4235.89 light years away from Earth or 1298.70 parsecs. It would take a spaceship travelling at the speed of light, 4235.89 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 Omicron Ceti 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. X Coronae Borealis brightness ranges from a magnitude of 12.649 to a magnitude of 9.056 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 243.2 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||X Coronae Borealis|
|Alternative Names||HD 141678, HIP 77460, X CrB|
|Constellation's Main Star||No|
|Multiple Star System||No / Unknown|
|Star Type||Variable Star|
|Visual / Apparent Magnitude||11.04|
|Naked Eye Visible||Requires a 4.5 - 6 Inch Telescope - Magnitudes|
|Right Ascension (R.A.)||15h 48m 53.53|
|Declination (Dec.)||+36° 14` 52.6|
|Galactic Latitude||51.51 degrees|
|Galactic Longitude||57.96 degrees|
|Distance from Earth||0.77 Parallax (milliarcseconds)|
|4235.89 Light Years|
|267,874,237.30 Astronomical Units|
|Radial Velocity||-104.00 ± 3.40 km/s|
|Variable Star Class||Pulsating|
|Variable Star Type||Omicron Ceti|
|Mean Variability Period in Days||243.200|
|Variable Magnitude Range (Brighter - Dimmer)||9.056 - 12.649|
|Calculated Effective Temperature||4,908 Kelvin|