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7 Bootis, HD121107, HIP67787, HR5225

7 Bootis is a white to yellow giant 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.

7 Bootis's Alternative Names

The Id of the star in the Yale Bright Star Catalogue is HR5225. HIP67787 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD121107.

Flamsteed designations are named after the creator, Sir John Flamsteed. Sir John numbered the stars in the constellation with a number and the latin name, this star's Flamsteed designation is 7 Bootis with it shortened to 7 Boo.

BD number is the number that the star was filed under in the Durchmusterung or Bonner Durchmusterung, a star catalogue that was put together by the Bonn Observatory between 1859 to 1903. The star's BD Number is BD+18 2795.

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

Location of 7 Bootis

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 7 Bootis, the location is 13h 53m 12.95 and +17° 55` 58.3 .

Proper Motion of 7 Bootis

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 6.71 ± 0.76 miliarcseconds/year towards the north and -34.02 ± 1.04 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 -11.80000 km/s with an error of about 0.30 km/s .

Physical Properties (Colour, Temperature) of 7 Bootis

7 Bootis has a spectral type of G5III. This means the star is a white to yellow giant star. The star has a B-V Colour Index of 0.84 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,188 Kelvin.

7 Bootis Radius has been calculated as being 17.49 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 12,172,975.03.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 17.66. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

7 Bootis Apparent and Absolute Magnitudes

7 Bootis has an apparent magnitude of 5.71 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 -0.90 If you used the 2007 Parallax value, you would get an absolute magnitude of -0.92. 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 7 Bootis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 4.77 which gave the calculated distance to 7 Bootis as 683.78 light years away from Earth or 209.64 parsecs. It would take a spaceship travelling at the speed of light, 683.78 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 4.73 which put 7 Bootis at a distance of 689.56 light years or 211.42 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.

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7 Bootis Facts

Visual Facts

Alternative NamesHD 121107, HIP 67787, HR 5225, 7 Boo, BD+18 2795
Star TypeGiant Star
GalaxyMilky Way
Absolute Magnitude-0.90 / -0.92
Visual / Apparent Magnitude5.71
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)13h 53m 12.95
Declination (Dec.)+17° 55` 58.3
Galactic Latitude73.05 degrees
Galactic Longitude3.30 degrees
1997 Distance from Earth4.77 Parallax (milliarcseconds)
 683.78 Light Years
 209.64 Parsecs
2007 Revised Distance from Earth4.73 Parallax (milliarcseconds)
 689.56 Light Years
 211.42 Parsecs
Proper Motion Dec.6.71 ± 0.76 milliarcseconds/year
Proper Motion RA.-34.02 ± 1.04 milliarcseconds/year
B-V Index0.84
Radial Velocity-11.80 ± 0.30 km/s
Spectral TypeG5III
Colour(G) White to Yellow

Estimated Facts

Calculated Effective Temperature5,188 Kelvin

Sources and Links

SIMBAD SourceLink

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