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Nekkar, Beta Bootis, 42 Bootis, HD133208, HIP73555, HR5602

Nekkar (Beta Bootis) is a white to yellow star that can be located in the constellation of Bootes. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

Beta Bootis is the Bayer Classification for the star. The Id of the star in the Yale Bright Star Catalogue is HR5602. HIP73555 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD133208.

Location of Nekkar

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 Nekkar, the location is 15h 01m 56.79 and +40d 23` 26.3 .

Proper Motion of Nekkar

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 -28.86 ± 0.11 miliarcseconds/year towards the north and -40.15 ± 0.14 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 -18.40000 km/s with an error of about 0.16 km/s .

Nekkar 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 113.0000000 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, Temperature, Radius) of Nekkar

Nekkar has a spectral type of G8III. This means the star is a white to yellow star. The star is 7387.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24093.6862212800000000s. The star has a B-V Colour Index of 0.95 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,948 Kelvin.

Nekkar Radius has been calculated as being 17.06 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 11,872,296.43.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 17.62. 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 0.03 with an error value of 9.99 Fe/H with the Sun has a value of 1 to put it into context.

Nekkar Apparent and Absolute Magnitudes

Nekkar has an apparent magnitude of 3.49 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 -0.64 If you used the 2007 Parallax value, you would get an absolute magnitude of -0.71. 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 Nekkar

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 14.91 which gave the calculated distance to Nekkar as 218.75 light years away from Earth or 67.07 parsecs. It would take a spaceship travelling at the speed of light, 218.75 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 14.48 which put Nekkar at a distance of 225.25 light years or 69.06 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 7,387.00 Parsecs or 24,093.69 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

Meteor Showers Radiating from near Nekkar

The June Bootids Meteor Shower radiants from a point near this star. The meteor shower runs typically between June 27-July 5 with a peak date of Jun. 28/29. The speed of a meteor in the shower is 14 Km/s. The amount of meteors predicted to be seen per hour (Zenith Hourly Rate) is 14.

The Quadrantids Meteor Shower radiants from a point near this star. The meteor shower runs typically between Jan 01 - Jan 05 with a peak date of Jan 03. The speed of a meteor in the shower is 41 Km/s. The amount of meteors predicted to be seen per hour (Zenith Hourly Rate) is 41.

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.

Nekkar Facts

Alternative Names

Traditional/Proper NameNekkar
Flamsteed Name42 Bootis
Flamsteed Short Name42 Boo
Bayer DesignationBeta Bootis
Hipparcos Library I.D.73555
Yale Bright Star Catalogue (HR) Id5602
Bonner DurchmusterungBD+40 2840
Henry Draper Designation133208

Visual Facts

Star Type star
Absolute Magnitude-0.64 / -0.71
Visual / Apparent Magnitude3.49
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)15h 01m 56.79
Declination (Dec.)+40d 23` 26.3
Galactic Latitude60.04 degrees
Galactic Longitude67.62 degrees
1997 Distance from Earth14.91 Parallax (milliarcseconds)
 218.75 Light Years
 67.07 Parsecs
2007 Revised Distance from Earth14.48 Parallax (milliarcseconds)
 225.25 Light Years
 69.06 Parsecs
Galacto-Centric Distance24,093.69 Light Years / 7,387.00 Parsecs
Proper Motion Dec.-28.86 ± 0.11 milliarcseconds/year
Proper Motion RA.-40.15 ± 0.14 milliarcseconds/year
B-V Index0.95
Radial Velocity-18.40 ± 0.16 km/s
Iron Abundance0.03 ± 9.99 Fe/H
Spectral TypeG8III
Colour(G) White to Yellow

Estimated Facts

Luminosity (x the Sun)113.0000000
Calculated Effective Temperature4,948 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Location of Nekkar in Bootes

Nekkar (Beta Bootis) Location in Bootes

The map was generated using Night Vision, an awesome free application by Brian Simpson.

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