Universe Guide

Delta Coronae Borealis (10 Coronae Borealis) Star Facts

Delta Coronae Borealis Facts

  • Delta Coronae Borealis is a eclipsing binary sys subgiant star that can be located in the constellation of Corona Borealis. The description is based on the spectral class.
  • Delta Coronae Borealis is a main star of the constellation outline.
  • Based on the spectral type (G5III-IV) of the star, the star's colour is yellow .
  • The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.
  • Using the most recent figures given by the 2007 Hipparcos data, the star is 170.05 light years away from us. Distance

Delta Coronae Borealis's Alternative Names

Delta Coronae Borealis (Del Crb) is the Bayer Classification for the star. The Bayer Classification was created by Johann Bayer in 1603. The brightest star in the constellation is normally given the Alpha designation, there are exceptions such as Pollux which is Beta Geminorum.

The Id of the star in the Yale Bright Star Catalogue is HR5889. 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.

Flamsteed designations are named after the creator, Sir John Flamsteed. Sir John named the stars in the constellation with a number and its latin name, this star's Flamsteed designation is 10 Coronae Borealis. The Flamsteed name can be shortened to 10 Crb.

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+26 2737.

More details on objects' alternative names can be found at Star Names .

Location of Delta Coronae Borealis

The location of the subgiant 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 object is compared to the celestial equator and is expressed in degrees. For Delta Coronae Borealis, the location is 15h 49m 35.70 and +26° 04` 06.8 .

Radial Velocity and Proper Motion of Delta Coronae Borealis

Proper Motion

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

Radial Velocity

The Radial Velocity, that is the speed at which the star is moving away/towards the Sun is -19.40000 km/s with an error of about 0.70 km/s . When the value is negative then the star and the Sun are getting closer to one another, likewise, a positive number means that two stars are moving away. Its nothing to fear as the stars are so far apart, they won't collide in our life-time, if ever.

Physical Properties of Delta Coronae Borealis

Delta Coronae Borealis Temperature and Colour

Based on the star's spectral type of G5III-IV , Delta Coronae Borealis's colour and type is yellow subgiant star. The star has a B-V Colour Index of 0.79 which means the star's temperature is about 5,311 Kelvin. The temperature was calculated using information from Morgans @ Uni.edu.

Delta Coronae Borealis Luminosity

Luminosity is the amount of energy that a star pumps out and its relative to the amount that our star, the Sun gives out. The figure of 40.45 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.

Delta Coronae Borealis Radius

Delta Coronae Borealis estimated 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. If you need the diameter of the star, you just need to multiple the radius by 2. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 6.958906245099808779345233018. The figure is derived at by using the formula from SDSS rather than peer reviewed papers. It has been known to produce widely incorrect figures.

Delta Coronae Borealis Iron Abundance

Delta Coronae Borealis 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. The value comes from the Hipparcos Extended Catalog.

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 19.71000 which gave the calculated distance to Delta Coronae Borealis as 165.48 light years away from Earth or 50.74 parsecs. If you want that in miles, it is about 972,794,926,754,423.78, based on 1 Ly = 5,878,625,373,183.61 miles.

In 2007, Hipparcos data was revised with a new parallax of 19.18000 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.

Using the 2007 distance, the star is roughly 10,754,572.06 Astronomical Units from the Earth/Sun give or take a few. An Astronomical Unit is the distance between Earth and the Sun. The number of A.U. is the number of times that the star is from the Earth compared to the Sun. 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*.

Travel Time to Delta Coronae Borealis

The time it will take to travel to this star is dependent on how fast you are going. U.G. has done some calculations as to how long it will take going at differing speeds. A note about the calculations, when I'm talking about years, I'm talking non-leap years only (365 days).

The New Horizons space probe is the fastest probe that we've sent into space at the time of writing. Its primary mission was to visit Pluto which at the time of launch (2006), Pluto was still a planet.

DescriptionSpeed (m.p.h.)Time (years)
Airbus A380736154,943,420.87
Speed of Sound (Mach 1)767.269148,628,913.41
Concorde (Mach 2)1,534.5474,314,359.85
New Horizons Probe33,0003,455,707.81
Speed of Light670,616,629.00170.05

Variable Type of Delta Coronae Borealis

The star is a eclipsing binary sys 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.

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Additional Delta Coronae Borealis Facts and Figures

Visual Facts

Primary / Proper / Traditional NameDelta Coronae Borealis
Alternative NamesDel Crb, HD 141714, HIP 77512, HR 5889, 10 Coronae Borealis, 10 Crb, BD+26 2737, del CrB
Spectral TypeG5III-IV
Constellation's Main StarYes
Multiple Star SystemNo / Unknown
Star TypeSubgiant Star
GalaxyMilky Way
ConstellationCorona Borealis
Absolute Magnitude 1.06 / 1.00
Visual / Apparent Magnitude4.59
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)15h 49m 35.70
Declination (Dec.)+26° 04` 06.8
Galactic Latitude50.37215047 degrees
Galactic Longitude41.87557088 degrees
1997 Distance from Earth19.71000 Parallax (milliarcseconds)
 165.48 Light Years
 50.74 Parsecs
2007 Distance from Earth19.18000 Parallax (milliarcseconds)
 170.05 Light Years
 52.14 Parsecs
 10,754,572.06 Astronomical Units
Galacto-Centric Distance24,054.55 Light Years / 7,375.00 Parsecs
Proper Motion Dec.-65.28000 ± 0.15000 milliarcseconds/year
Proper Motion RA.-78.83000 ± 0.26000 milliarcseconds/year
B-V Index0.79
Radial Velocity-19.40000 ± 0.70 km/s
Iron Abundance-0.2200 ± 9.99 Fe/H
Semi-Major Axis6326.0000000
Stellar Luminosity (Lsun)40.4500000

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Variable Star Details

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

Estimated Calculated Facts

Radius (x the Sun)6.96
Effective Temperature5,311 Kelvin

Sources and Links

SIMBAD SourceLink

Location of Delta Coronae Borealis in Corona Borealis

Delta Coronae Borealis Location in Corona Borealis

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

Corona Borealis Main Stars

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