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42 G. Aql, HD181907, HIP95222

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

HIP95222 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD181907. The Id of the star in the Gould Star Catalogue is 42. 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 42 G. Aql

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 42 G. Aql, the location is 19h 22m 21.51 and -00d 15` 08.2 .

Proper Motion of 42 G. Aql

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 -27.71 ± 0.18 miliarcseconds/year towards the north and 60.06 ± 0.34 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 -10.90000 km/s with an error of about 2.90 km/s .

42 G. Aql 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 42 G. Aql

42 G. Aql has a spectral type of G8III:. This means the star is a white to yellow star. The star is 7317.00000000 Parsecs from the Galactic Centre or terms of Light Years is 23865.3718804800000000s. The star has a B-V Colour Index of 1.09 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,682 Kelvin.

42 G. Aql Radius has been calculated as being 10.87 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 7,559,956.86.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 10.14. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

42 G. Aql Apparent and Absolute Magnitudes

42 G. Aql has an apparent magnitude of 5.81 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 0.58 If you used the 2007 Parallax value, you would get an absolute magnitude of 0.73. 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 42 G. Aql

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 8.98 which gave the calculated distance to 42 G. Aql as 363.21 light years away from Earth or 111.36 parsecs. It would take a spaceship travelling at the speed of light, 363.21 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 9.64 which put 42 G. Aql at a distance of 338.34 light years or 103.73 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 7,317.00 Parsecs or 23,865.37 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.

42 G. Aql Facts

Alternative Names

Traditional/Proper Name42 G. Aql
Hipparcos Library I.D.95222
Bonner DurchmusterungBD-00 3725
Gould I.D.42
Henry Draper Designation181907

Visual Facts

Star Type star
Absolute Magnitude0.58 / 0.73
Visual / Apparent Magnitude5.81
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)19h 22m 21.51
Declination (Dec.)-00d 15` 08.2
Galactic Latitude-6.99 degrees
Galactic Longitude36.25 degrees
1997 Distance from Earth8.98 Parallax (milliarcseconds)
 363.21 Light Years
 111.36 Parsecs
2007 Revised Distance from Earth9.64 Parallax (milliarcseconds)
 338.34 Light Years
 103.73 Parsecs
Galacto-Centric Distance23,865.37 Light Years / 7,317.00 Parsecs
Proper Motion Dec.-27.71 ± 0.18 milliarcseconds/year
Proper Motion RA.60.06 ± 0.34 milliarcseconds/year
B-V Index1.09
Radial Velocity-10.90 ± 2.90 km/s
Spectral TypeG8III:
Colour(G) White to Yellow

Estimated Facts

Luminosity (x the Sun)113.0000000
Calculated Effective Temperature4,682 Kelvin

Sources and Links

SIMBAD SourceLink

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