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Kitalpha, Alpha Equulei, 8 Equulei, HD202447, HIP104987, HR8131

Kitalpha (Alpha Equulei) is a white to yellow giant star that can be located in the constellation of Equuleus. Kitalpha is the 1st brightest star in Equuleus 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.

Alpha Equulei is the Bayer Classification for the star. The Id of the star in the Yale Bright Star Catalogue is HR8131. HIP104987 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD202447.

Location of Kitalpha

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 Kitalpha, the location is 21h 15m 49.40 and +05d14`53.1 .

Proper Motion of Kitalpha

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 -94.09 ± 0.16 miliarcseconds/year towards the north and 59.88 ± 0.21 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of Kitalpha

Kitalpha has a spectral type of G0III+.... This means the star is a white to yellow giant star. The star is 7372.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24044.7617196800000000s. The star has a B-V Colour Index of 0.54 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 6,122 Kelvin.

Kitalpha Radius has been calculated as being 7.78 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 5,415,016.76.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 7.96. 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 0.18 with an error value of 0.06 Fe/H with the Sun has a value of 1 to put it into context.

Kitalpha Apparent and Absolute Magnitudes

Kitalpha has an apparent magnitude of 3.92 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 0.14 If you used the 2007 Parallax value, you would get an absolute magnitude of 0.09. 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 Kitalpha

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 17.51 which gave the calculated distance to Kitalpha as 186.27 light years away from Earth or 57.11 parsecs. It would take a spaceship travelling at the speed of light, 186.27 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 17.14 which put Kitalpha at a distance of 190.29 light years or 58.34 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 7,372.00 Parsecs or 24,044.76 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

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.

Kitalpha Facts

Alternative Names

Traditional/Proper NameKitalpha
Flamsteed Name8 Equulei
Flamsteed Short Name8 Equ
Bayer DesignationAlpha Equulei
Hipparcos Library I.D.104987
Yale Bright Star Catalogue (HR) Id8131
Bonner DurchmusterungBD+04 4635
Henry Draper Designation202447

Visual Facts

Star Typegiant star
Absolute Magnitude0.14 / 0.09
Visual / Apparent Magnitude3.92
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)21h 15m 49.40
Declination (Dec.)+05d14`53.1
Galactic Latitude-28.71 degrees
Galactic Longitude56.38 degrees
1997 Distance from Earth17.51 Parallax (milliarcseconds)
 186.27 Light Years
 57.11 Parsecs
2007 Revised Distance from Earth17.14 Parallax (milliarcseconds)
 190.29 Light Years
 58.34 Parsecs
Galacto-Centric Distance24,044.76 Light Years / 7,372.00 Parsecs
Proper Motion Dec.-94.09 ± 0.16 milliarcseconds/year
Proper Motion RA.59.88 ± 0.21 milliarcseconds/year
B-V Index0.54
Radial Velocity-16.26 ± 0.06 km/s
Iron Abundance0.18 ± 0.06 Fe/H
Spectral TypeG0III+...
Colour(G) White to Yellow

Estimated Facts

Calculated Effective Temperature6,122 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Multi-Star System

The star has been identified as being a multi-star system, one in which there is at least one star in close orbit to another star or two or more stars orbiting a central point. The stars may be of equal mass, unequal mass where one star is stronger than the other or be in groups orbiting a central point which doesn't necessarily have to be a star. More information can be found on my dedicated multiple star systems page. The source of the info is Simbad. The file is dated 2000 so any differences between this and any other source will be down to the actual source from where the information came from.


Proper Motion mas/yr
H.D. IdB.D. IdStar CodeMagnitudeR.A.Dec.SpectrumColourYear
202447+04 4635.0A4.1000056.00000-84.00000F8Yellow/White
202448BA3White1949

Location of Kitalpha in Equuleus


Kitalpha (Alpha Equulei) Location in Equuleus

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


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