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Delta Coronae Borealis, 10 Coronae Borealis, HD141714, HIP77512

Delta Coronae Borealis is a white to yellow eclipsing binary system subgiant star that can be located in the constellation of CoronaBorealis. Delta Coronae Borealis is the brightest star in Corona Borealis based on the Hipparcos 2007 apparent magnitude. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

Delta Coronae Borealis is the Bayer Classification for the star. HIP77512 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD141714.

Delta Coronae Borealis has alternative name(s), del CrB.

Location of Delta Coronae Borealis

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 Delta Coronae Borealis, the location is 15h 49m 35.70 and +26d04`06.8 .

Proper Motion of Delta Coronae Borealis

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 -65.28 ± 0.15 miliarcseconds/year towards the north and -78.83 ± 0.26 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of Delta Coronae Borealis

Delta Coronae Borealis has a spectral type of G5III-IV. This means the star is a white to yellow subgiant star. The star is 7375.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24054.5466200000000000s. The star has a B-V Colour Index of 0.79 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,311 Kelvin.

Delta Coronae Borealis Radius has been calculated as being 6.77 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 4,710,042.44.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 6.96. 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 -0.22 with an error value of 9.99 Fe/H with the Sun has a value of 1 to put it into context.

Delta Coronae Borealis Apparent and Absolute Magnitudes

Delta Coronae Borealis has an apparent magnitude of 4.59 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 1.06 If you used the 2007 Parallax value, you would get an absolute magnitude of 1.00. 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 Delta Coronae Borealis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 19.71 which gave the calculated distance to Delta Coronae Borealis as 165.48 light years away from Earth or 50.74 parsecs. It would take a spaceship travelling at the speed of light, 165.48 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 19.18 which put Delta Coronae Borealis at a distance of 170.05 light years or 52.14 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.

The star's Galacto-Centric Distance is 7,375.00 Parsecs or 24,054.55 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

Variable Type of Delta Coronae Borealis

The star is a eclipsing binary system RS Canum Venaticorum 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. Delta Coronae Borealis brightness ranges from a magnitude of 4.763 to a magnitude of 4.729 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.0 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.

Delta Coronae Borealis Facts

Alternative Names

Flamsteed Name10 Coronae Borealis
Flamsteed Short Name10 CrB
Short Namedel CrB
Bayer DesignationDelta Coronae Borealis
Hipparcos Library I.D.77512
Bonner DurchmusterungBD+26 2737
Henry Draper Designation141714

Visual Facts

Star Typesubgiant star
Absolute Magnitude1.06 / 1.00
Visual / Apparent Magnitude4.59
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)15h 49m 35.70
Declination (Dec.)+26d04`06.8
Galactic Latitude50.37 degrees
Galactic Longitude41.88 degrees
1997 Distance from Earth19.71 Parallax (milliarcseconds)
 165.48 Light Years
 50.74 Parsecs
2007 Revised Distance from Earth19.18 Parallax (milliarcseconds)
 170.05 Light Years
 52.14 Parsecs
Galacto-Centric Distance24,054.55 Light Years / 7,375.00 Parsecs
Proper Motion Dec.-65.28 ± 0.15 milliarcseconds/year
Proper Motion RA.-78.83 ± 0.26 milliarcseconds/year
B-V Index0.79
Radial Velocity-19.40 ± 0.70 km/s
Iron Abundance-0.22 ± 9.99 Fe/H
Spectral TypeG5III-IV
Colour(G) White to Yellow

Variable Star Details

Variable Star ClassEclipsing binary system
Variable Star TypeRS Canum Venaticorum
Mean Variability Period in Days0.025
Variable Magnitude Range (Brighter - Dimmer)4.729 - 4.763

Estimated Facts

Calculated Effective Temperature5,311 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Location of Delta Coronae Borealis in Corona Borealis

Delta Coronae Borealis (Delta Coronae Borealis) Location in Corona Borealis

The map was generated using Night Vision, an awesome free application by Brian Simpson.

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