Universe Guide


13 G. Sagittarii - HD163685 - HIP88012

13 G. Sagittarii is a blue giant star that can be located in the constellation of Sagittarius. HIP88012 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD163685. The Id of the star in the Gould Star Catalogue is 13. 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.

Location of 13 G. Sagittarii

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 13 G. Sagittarii, the location is 17h 58m 39.05 and -28d45`32.7 .

Proper Motion of 13 G. Sagittarii

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 -004.92 ± 000.24 towards the north and -001.53 ± 000.41 east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of 13 G. Sagittarii

13 G. Sagittarii has a spectral type of B3II/III. This means the star is a blue coloured giant star. The star has a B-V Colour Index of -0.07 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 10,845 Kelvin.

13 G. Sagittarii has been calculated as 6.83 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 4,752,793.46.km.

13 G. Sagittarii Apparent and Absolute Magnitudes

13 G. Sagittarii has an apparent magnitude of 5.99 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 -2.06 If you used the 2007 Parallax value, you would get an absolute magnitude of -2.73. 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 13 G. Sagittarii

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 2.45 which gave the calculated distance to 13 G. Sagittarii as 1331.28 light years away from Earth or 408.16 parsecs. In 2007, Hipparcos data was revised with a new parallax of 1.80 which put 13 G. Sagittarii at a distance of 1812.02 light years or 555.56 parsecs.

It would take a spaceship travelling at the speed of light, 1331.28 years using the 1997 distance to get there. We don't have the technology or spaceship that can carry people over that distance yet.

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 Stellar Age, Metallicity or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

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13 G. Sagittarii Facts

Alternative Names

Traditional Name13 G. Sagittarii
Hipparcos Library I.D.88012
Gould I.D.13
Henry Draper Designation163685

Visual Facts

Star Typegiant star
Absolute Magnitude-2.06 / -2.73
Apparent Magnitude5.99
Right Ascension (R.A.)17h 58m 39.05
Declination (Dec.)-28d45`32.7
1997 Distance from Earth2.45 Parallax (milliarcseconds)
 1331.28 Light Years
 408.16 Parsecs
2007 Distance from Earth1.80 Parallax (milliarcseconds)
 1812.02 Light Years
 555.56 Parsecs
Proper Motion Dec.-4.92 ± 0.24 milliarcseconds/year
Proper Motion RA.-1.53 ± 0.41 milliarcseconds/year
B-V Index-0.07
Spectral TypeB3II/III
Colour(B) blue

Estimated Facts

Radius (x the Sun)6.83
Calculated Effective Temperature10,845 Kelvin

Sources and Links

SIMBAD SourceLink

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