Universe Guide
HomeAliensConstellationsTelevision and Films ListFact ListGames ListWarcraftSearchTwitterFacebook

243 G. Centauri, HD118666, HIP66681

243 G. Centauri is a blue to white subgiant star that can be located in the constellation of Centaurus. 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. The star has an estimated age of 1.30 Billion of Years but could be as young as 1.20 to 1.40 according to Hipparcos.

243 G. Centauri's Alternative Names

HIP66681 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD118666.

The Gould star designation is one that was designed by American astronomer, Benjamin Apthorp Gould. Gould stars are predominantly in the Southern and Equatorial constellations but do appear in northern constellations such as Bootes and Orion. The star has the designation 243 G. Centauri. There are no stars with a Gould designation in Ursa Major for example.

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

Location of 243 G. Centauri

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 243 G. Centauri, the location is 13h 40m 10.80 and -64° 34` 35.6 .

Proper Motion of 243 G. Centauri

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 0.60 ± 0.28 miliarcseconds/year towards the north and -69.79 ± 0.40 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 3.70000 km/s with an error of about 2.10 km/s .

243 G. Centauri 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 19.52 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.

Physical Properties (Colour, Temperature, Age) of 243 G. Centauri

243 G. Centauri has a spectral type of F3III-IV. This means the star is a blue to white subgiant star. The star is 7,357.00 Parsecs from the Galactic Centre or terms of Light Years is 23,995.84 s. The star has a B-V Colour Index of 0.4 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 6,728 Kelvin.

243 G. Centauri Radius has been calculated as being 3.30 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 2,299,324.44.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 3.32. 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 -0.12 with an error value of 0.15 Fe/H with the Sun has a value of 1 to put it into context.

The stars age according to Hipparcos data files put the star at an age of about 1.30 Billion years old but could be between 1.20 and 1.40 Billion years old. In comparison, the Sun's age is about 4.6 Billion Years Old.

243 G. Centauri Apparent and Absolute Magnitudes

243 G. Centauri has an apparent magnitude of 5.79 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 1.59 If you used the 2007 Parallax value, you would get an absolute magnitude of 1.58. 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 243 G. Centauri

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 14.44 which gave the calculated distance to 243 G. Centauri as 225.87 light years away from Earth or 69.25 parsecs. It would take a spaceship travelling at the speed of light, 225.87 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 14.40 which put 243 G. Centauri at a distance of 226.50 light years or 69.44 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 7,357.00 Parsecs or 23,995.84 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.

Hide Explanations
Show GridLines

243 G. Centauri Facts

Visual Facts


Primary / Proper / Traditional Name243 G. Centauri
Alternative NamesHD 118666, HIP 66681
Spectral TypeF3III-IV
Multiple Star SystemNo / Unknown
Star TypeSubgiant Star
Colour blue to white
GalaxyMilky Way
ConstellationCentaurus
Age1.30 Billion Years Old
Age Range1.20 - 1.40 Billion Years Old
Absolute Magnitude1.59 / 1.58
Visual / Apparent Magnitude5.79
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)13h 40m 10.80
Declination (Dec.)-64° 34` 35.6
Galactic Latitude-2.20 degrees
Galactic Longitude308.13 degrees
1997 Distance from Earth14.44 Parallax (milliarcseconds)
 225.87 Light Years
 69.25 Parsecs
2007 Distance from Earth14.40 Parallax (milliarcseconds)
 226.50 Light Years
 69.44 Parsecs
Galacto-Centric Distance23,995.84 Light Years / 7,357.00 Parsecs
Proper Motion Dec.0.60 ± 0.28 milliarcseconds/year
Proper Motion RA.-69.79 ± 0.40 milliarcseconds/year
B-V Index0.40
Radial Velocity3.70 ± 2.10 km/s
Iron Abundance-0.12 ± 0.15 Fe/H
Eccentricity0.02
Semi-Major Axis7177.00
Stellar Luminosity (Lsun)19.52

Companions (Multi-Star and Exoplanets) Facts


Exoplanet CountNone/Unaware

Estimated Facts


Calculated Effective Temperature6,728 Kelvin

Sources and Links


SIMBAD SourceLink

Related Stars


Add a Comment


Name:
Email: (Optional)
Comment: