Universe Guide

172 G. Centauri

172 G. Centauri Facts

  • 172 G. Centauri is a giant star that can be located in the constellation of Centaurus. The description is based on the spectral class.
  • 172 G. Centauri is not part of the constellation outline but is within the borders of the constellation.
  • Based on the spectral type (K0II/III) of the star, the star's colour is orange to red .
  • 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 344.42 light years away from us. Distance

172 G. Centauri's Alternative Names

HIP63972 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD113778.

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 172 G. Centauri. There are no stars with a Gould designation in Ursa Major for example.

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

Location of 172 G. Centauri

The location of the giant 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 172 G. Centauri, the location is 13h 06m 35.05 and -41° 35` 18.3 .

Radial Velocity and Proper Motion of 172 G. Centauri

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 -14.48 ± 0.19 milliarcseconds/year towards the north and 44.53 ± 0.30 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 1.90000 km/s with an error of about 0.40 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 172 G. Centauri

172 G. Centauri Colour and Temperature

Based on the star's spectral type of K0II/III , 172 G. Centauri's colour and type is orange to red giant star. The star has a B-V Colour Index of 1.05 which means the star's temperature is about 4,755 Kelvin. The temperature was calculated using information from Morgans @ Uni.edu.

172 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 82.61 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.

172 G. Centauri Radius

172 G. Centauri estimated radius has been calculated as being 10.88 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 7,569,754.25.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 11.081479541945613718272033764. 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.

172 G. Centauri Apparent and Absolute Magnitudes

172 G. Centauri has an apparent magnitude of 5.59 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 0.51 If you used the 2007 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.

Distance to 172 G. Centauri

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 9.62000 which gave the calculated distance to 172 G. Centauri as 339.05 light years away from Earth or 103.95 parsecs. If you want that in miles, it is about 1,993,147,932,777,902.97, based on 1 Ly = 5,878,625,373,183.61 miles.

In 2007, Hipparcos data was revised with a new parallax of 9.47000 which put 172 G. Centauri at a distance of 344.42 light years or 105.60 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 21,781,411.76 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 7,343.00 Parsecs or 23,950.17 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 172 G. Centauri

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 A380736313,823,069.78
Speed of Sound (Mach 1)767.269301,033,639.26
Concorde (Mach 2)1,534.54150,516,623.46
New Horizons Probe33,0006,999,205.44
Speed of Light670,616,629.00344.42

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

Additional 172 G. Centauri Facts and Figures

Visual Facts

Primary / Proper / Traditional Name172 G. Centauri
Alternative NamesHD 113778, HIP 63972
Spectral TypeK0II/III
Constellation's Main StarNo
Multiple Star SystemNo / Unknown
Star TypeGiant Star
ColourOrange to Red
GalaxyMilky Way
Absolute Magnitude 0.51 / 0.47
Visual / Apparent Magnitude5.59
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)13h 06m 35.05
Declination (Dec.)-41° 35` 18.3
Galactic Latitude21.19401809 degrees
Galactic Longitude305.96866934 degrees
1997 Distance from Earth9.62000 Parallax (milliarcseconds)
 339.05 Light Years
 103.95 Parsecs
2007 Distance from Earth9.47000 Parallax (milliarcseconds)
 344.42 Light Years
 105.60 Parsecs
 21,781,411.76 Astronomical Units
Galacto-Centric Distance23,950.17 Light Years / 7,343.00 Parsecs
Proper Motion Dec.-14.48000 ± 0.19000 milliarcseconds/year
Proper Motion RA.44.53000 ± 0.30000 milliarcseconds/year
B-V Index1.05
Radial Velocity1.90000 ± 0.40 km/s
Semi-Major Axis9387.0000000
Stellar Luminosity (Lsun)82.6100000

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Estimated Calculated Facts

Radius (x the Sun)11.08
Effective Temperature4,755 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Comments and Questions

There's no register feature and no need to give an email address if you don't need to. All messages will be reviewed before being displayed. Comments may be merged or altered slightly such as if an email address is given in the main body of the comment.

You can decline to give a name which if that is the case, the comment will be attributed to a random star. A name is preferred even if its a random made up one by yourself.

This website is using cookies. More info. That's Fine