Universe Guide


202 G. Aqr, HD217563, HIP113686

202 G. Aqr is a orange to red star that can be located in the constellation of Aquarius. 202 G. Aqr is the brightest star in Aquarius based on the Hipparcos 2007 apparent magnitude. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

HIP113686 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD217563. The Id of the star in the Gould Star Catalogue is 202. 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 202 G. Aqr

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 202 G. Aqr, the location is 23h 01m 31.70 and -04d42`41.3 .

Proper Motion of 202 G. Aqr

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 7.65 ± 0.46 miliarcseconds/year towards the north and 12.80 ± 0.57 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of 202 G. Aqr

202 G. Aqr has a spectral type of K0. This means the star is a orange to red star. The star has a B-V Colour Index of 0.99 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,994 Kelvin.

202 G. Aqr Radius has been calculated as being 65.77 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 45,764,233.78.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 36.65. 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 -0.10 with an error value of 0.06 Fe/H with the Sun has a value of 1 to put it into context.

202 G. Aqr Apparent and Absolute Magnitudes

202 G. Aqr has an apparent magnitude of 5.94 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 -3.61 If you used the 2007 Parallax value, you would get an absolute magnitude of -2.34. 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 202 G. Aqr

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 1.23 which gave the calculated distance to 202 G. Aqr as 2651.73 light years away from Earth or 813.01 parsecs. It would take a spaceship travelling at the speed of light, 2651.73 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 2.21 which put 202 G. Aqr at a distance of 1475.85 light years or 452.49 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.

202 G. Aqr Facts

Alternative Names

Traditional/Proper Name202 G. Aqr
Hipparcos Library I.D.113686
Bonner DurchmusterungBD-05 5910
Gould I.D.202
Henry Draper Designation217563

Visual Facts

Star Type star
Absolute Magnitude-3.61 / -2.34
Visual / Apparent Magnitude5.94
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)23h 01m 31.70
Declination (Dec.)-04d42`41.3
Galactic Latitude-55.53 degrees
Galactic Longitude68.60 degrees
1997 Distance from Earth1.23 Parallax (milliarcseconds)
 2651.73 Light Years
 813.01 Parsecs
2007 Revised Distance from Earth2.21 Parallax (milliarcseconds)
 1475.85 Light Years
 452.49 Parsecs
Proper Motion Dec.7.65 ± 0.46 milliarcseconds/year
Proper Motion RA.12.80 ± 0.57 milliarcseconds/year
B-V Index0.99
Radial Velocity4.66 ± 0.10 km/s
Iron Abundance-0.10 ± 0.06 Fe/H
Spectral TypeK0
Colour(K) Orange to Red

Estimated Facts

Calculated Effective Temperature4,994 Kelvin

Sources and Links

SIMBAD SourceLink

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