Universe Guide


V766 Centauri, HD119796, HIP67261, HR5171

V766 Centauri is a white to yellow eruptive very luminous supergiant star that can be located in the constellation of Centaurus. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

The Id of the star in the Yale Bright Star Catalogue is HR5171. HIP67261 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD119796. The Id of the star in the Gould Star Catalogue is 264. Stars in the southern hemisphere are more likely to have a Gould Id than the northern hemisphere. For example, there are no Gould classified stars in Ursa Major.

V766 Centauri has alternative name(s), HR 5171 , V766 Cen.

In the Hipparcos catalogue of 1997, the star is recorded as A7p in the data download file whereas everywhere else says it is G8. The source of information about stars on this site is the Hipparcos data file and the Hipparcos Double Star file. The latter file has the matching Spectral Type. It is also said that this star is the largest yellow supergiant so far discovered.

The star is a double star where the second star is smaller and feeds into the larger. To get an idea of what I mean, watch the Nemesis Maturity video to explain it better. It is better known by its HR id rather than by its V, Hip or HD Id.

Location of V766 Centauri

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 V766 Centauri, the location is 13h 47m 10.87 and -62d35`22.9 .

Proper Motion of V766 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 -2.54 ± 0.92 miliarcseconds/year towards the north and -2.94 ± 1.59 miliarcseconds/year east if we saw them in the horizon.

V766 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 1.0000000 that I have given is based on the Spectral Types page that I have found on the Internet. You might find a different figure, one that may have been calculated rather than generalised that I have done. The figure is always the amount times the luminosity of the Sun. It is an imprecise figure because of a number of factors including but not limited to whether the star is a variable star and distance.

Physical Properties (Colour, Radius) of V766 Centauri

V766 Centauri has a spectral type of G8Ia++B0Ibp. This means the star is a white to yellow supergiant star. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

V766 Centauri Apparent and Absolute Magnitudes

V766 Centauri has an apparent magnitude of 6.40 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 -6.36 If you used the 2007 Parallax value, you would get an absolute magnitude of -2.95. 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 V766 Centauri

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 0.28 which gave the calculated distance to V766 Centauri as 11648.69 light years away from Earth or 3571.43 parsecs. It would take a spaceship travelling at the speed of light, 11648.69 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 1.35 which put V766 Centauri at a distance of 2416.02 light years or 740.74 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.

Variable Type of V766 Centauri

The star is a eruptive S Doradus. S Doradus is a star in the Large Magellanic Cloud, not the Milky Way 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. V766 Centauri brightness ranges from a magnitude of 6.810 to a magnitude of 6.550 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.3 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.

V766 Centauri Facts

Alternative Names

Traditional/Proper NameV766 Centauri
Short NameV766 Cen
Alternative Name(s)HR 5171
Hipparcos Library I.D.67261
Yale Bright Star Catalogue (HR) Id5171
Gould I.D.264
Henry Draper Designation119796

Visual Facts

Star Typesupergiant star
Absolute Magnitude-6.36 / -2.95
Visual / Apparent Magnitude6.40
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)13h 47m 10.87
Declination (Dec.)-62d35`22.9
Galactic Latitude-0.41 degrees
Galactic Longitude309.30 degrees
1997 Distance from Earth0.28 Parallax (milliarcseconds)
 11648.69 Light Years
 3571.43 Parsecs
2007 Revised Distance from Earth1.35 Parallax (milliarcseconds)
 2416.02 Light Years
 740.74 Parsecs
Proper Motion Dec.-2.54 ± 0.92 milliarcseconds/year
Proper Motion RA.-2.94 ± 1.59 milliarcseconds/year
B-V Index-99.00
Radial Velocity-38.20 ± 0.60 km/s
Spectral TypeG8Ia++B0Ibp
Colour(G) White to Yellow

Variable Star Details

Variable Star ClassEruptive
Variable Star TypeS Doradus. S Doradus is a star in the Large Magellanic Cloud, not the Milky Way
Mean Variability Period in Days0.265
Variable Magnitude Range (Brighter - Dimmer)6.550 - 6.810
Luminosity (x the Sun)1.0000000

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
119796-61 4003.4A6.20000-20.00000-14.00000G5Yellow

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