Universe Guide
AliensAliensConstellationsTelevision and Films ListFact ListGames ListWarcraftSearchTwitterFacebook


Mu Herculis, 86 Herculis, HD161797, HIP86974, HR6623

Mu Herculis is a white to yellow star that can be located in the constellation of Hercules. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

Mu Herculis is the Bayer Classification for the star. The Id of the star in the Yale Bright Star Catalogue is HR6623. HIP86974 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD161797. The Gliese ID of the star is GL 695Aa. The star was part of the original catalogue devised by German Astronomer Wilheim Gliese of stars located within 20 parsecs of Earth. Ref : Star Names.

Location of Mu Herculis

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 Mu Herculis, the location is 17h 46m 27.72 and +27d 43` 21.0 .

Proper Motion of Mu Herculis

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 -749.60 ± 0.12 miliarcseconds/year towards the north and -291.66 ± 0.16 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 -17.07000 km/s with an error of about 0.12 km/s .

Physical Properties (Colour, Temperature, Radius) of Mu Herculis

Mu Herculis has a spectral type of G5IV. This means the star is a white to yellow star. The star is 7395.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24119.7792888000000000s. The star has a B-V Colour Index of 0.75 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,418 Kelvin.

Mu Herculis Radius has been calculated as being 1.84 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,281,364.01.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 1.82. 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 0.23 with an error value of 0.01 Fe/H with the Sun has a value of 1 to put it into context.

Mu Herculis Apparent and Absolute Magnitudes

Mu Herculis has an apparent magnitude of 3.42 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 3.80 If you used the 2007 Parallax value, you would get an absolute magnitude of 3.82. 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 Mu Herculis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 119.05 which gave the calculated distance to Mu Herculis as 27.40 light years away from Earth or 8.40 parsecs. It would take a spaceship travelling at the speed of light, 27.40 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 120.33 which put Mu Herculis at a distance of 27.11 light years or 8.31 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 7,395.00 Parsecs or 24,119.78 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.

Mu Herculis Facts

Alternative Names

Flamsteed Name86 Herculis
Flamsteed Short Name86 Her
Bayer DesignationMu Herculis
Hipparcos Library I.D.86974
Yale Bright Star Catalogue (HR) Id6623
Bonner DurchmusterungBD+27 2888
Gliese IDGL 695Aa
Henry Draper Designation161797

Visual Facts

Star Type star
Absolute Magnitude3.80 / 3.82
Visual / Apparent Magnitude3.42
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)17h 46m 27.72
Declination (Dec.)+27d 43` 21.0
Galactic Latitude25.63 degrees
Galactic Longitude52.44 degrees
1997 Distance from Earth119.05 Parallax (milliarcseconds)
 27.40 Light Years
 8.40 Parsecs
2007 Revised Distance from Earth120.33 Parallax (milliarcseconds)
 27.11 Light Years
 8.31 Parsecs
Galacto-Centric Distance24,119.78 Light Years / 7,395.00 Parsecs
Proper Motion Dec.-749.60 ± 0.12 milliarcseconds/year
Proper Motion RA.-291.66 ± 0.16 milliarcseconds/year
B-V Index0.75
Radial Velocity-17.07 ± 0.12 km/s
Iron Abundance0.23 ± 0.01 Fe/H
Spectral TypeG5IV
Colour(G) White to Yellow

Estimated Facts

Calculated Effective Temperature5,418 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
161797+27 2888.0A3.50000-309.00000-748.00000G5Yellow

Add a Comment

Email: (Optional)