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WR 66 - HD134877 - HIP74634

WR 66 is a Wolf-Rayet star that can be located in the constellation of Circinus. The star can not be seen by the naked eye, you need a telescope to see it.

HIP74634 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD134877.

Location of WR 66

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 WR 66, the location is 15h 14m 57.72 and -59d50`30.2 .

Wolf-Rayet Star

The star is a Wolf-Rayet, a rare type of star of which not many are known. These stars are extremely luminous and large compared to our Sun. They live fast and die hard in a matter of millions not billions of years like our Sun. They exhaust their hydrogen supplies, turning to other gasses and expand outwards with massive solar winds, moving a step closer in the stellar evolution towards their death in a super or hypernova explosion.

Proper Motion of WR 66

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 -8.49 ± 2.60 miliarcseconds/year towards the north and -5.04 ± 3.75 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Temperature, Radius) of WR 66

WR 66 has a spectral type of WN.... This means the star is a Wolf-Rayet star. The star has a B-V Colour Index of 0.85 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,308 Kelvin.

WR 66 Radius has been calculated as being 1.32 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 915,125.47.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 1.18. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

WR 66 Apparent and Absolute Magnitudes

WR 66 has an apparent magnitude of 11.34 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 4.62 If you used the 2007 Parallax value, you would get an absolute magnitude of 4.86. 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 WR 66

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 4.52 which gave the calculated distance to WR 66 as 721.60 light years away from Earth or 221.24 parsecs. It would take a spaceship travelling at the speed of light, 721.60 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 5.06 which put WR 66 at a distance of 644.59 light years or 197.63 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.

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.

WR 66 Facts

Alternative Names

Traditional/Proper NameWR 66
Hipparcos Library I.D.74634
Henry Draper Designation134877
Wolf-Rayet Id66

Visual Facts

Star Type Wolf-Rayet star
Absolute Magnitude4.62 / 4.86
Visual / Apparent Magnitude11.34
Naked Eye VisibleRequires a 4.5 - 6 Inch Telescope - Ref: Wiki
Right Ascension (R.A.)15h 14m 57.72
Declination (Dec.)-59d50`30.2
Galactic Latitude-1.83 degrees
Galactic Longitude320.07 degrees
1997 Distance from Earth4.52 Parallax (milliarcseconds)
 721.60 Light Years
 221.24 Parsecs
2007 Revised Distance from Earth5.06 Parallax (milliarcseconds)
 644.59 Light Years
 197.63 Parsecs
Proper Motion Dec.-8.49 ± 2.60 milliarcseconds/year
Proper Motion RA.-5.04 ± 3.75 milliarcseconds/year
B-V Index0.85
Spectral TypeWN...

Estimated Facts

Calculated Effective Temperature5,308 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
134877A11.80000-4.00000-12.00000WN
B12.90000-4.00000-12.000001991

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