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87 G. Aql - HD187734 - HIP97709

87 G. Aql is a orange to red star that can be located in the constellation of Aquila. HIP97709 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD187734. The Id of the star in the Gould Star Catalogue is 87. 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 87 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 87 G. Aql, the location is 19h 51m 26.84 and +04d05`19.1 .

Proper Motion of 87 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 -005.82 ± 000.61 towards the north and -001.70 ± 000.86 east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of 87 G. Aql

87 G. Aql 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 1.34 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,316 Kelvin.

87 G. Aql Apparent and Absolute Magnitudes

87 G. Aql has an apparent magnitude of 6.47 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 If you used the 2007 Parallax value, you would get an absolute magnitude of -2.94. 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 87 G. Aql

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as -0.37 which gave the calculated distance to 87 G. Aql as -8815.23 light years away from Earth or -2702.70 parsecs. It would take a spaceship travelling at the speed of light, -8815.23 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 1.31 which put 87 G. Aql at a distance of 2489.80 light years or 763.36 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 Stellar Age, Metallicity or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

87 G. Aql Facts

Alternative Names

Traditional Name87 G. Aql
Hipparcos Library I.D.97709
Bonner DurchmusterungBD+03 4172
Gould I.D.87
Henry Draper Designation187734

Visual Facts

Star Type star
Apparent Magnitude6.47
Right Ascension (R.A.)19h 51m 26.84
Declination (Dec.)+04d05`19.1
1997 Distance from Earth-0.37 Parallax (milliarcseconds)
 -8815.23 Light Years
 -2702.70 Parsecs
2007 Revised Distance from Earth1.31 Parallax (milliarcseconds)
 2489.80 Light Years
 763.36 Parsecs
Proper Motion Dec.-5.82 ± 0.61 milliarcseconds/year
Proper Motion RA.-1.70 ± 0.86 milliarcseconds/year
B-V Index1.34
Spectral TypeK0...
Colour (K) Orange to Red

Estimated Facts

Calculated Effective Temperature4,316 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Multi-Star System

The star has been identified as being a multi-star system, one in which there is at least one star in close orbit to another star or two or more stars orbiting a central point. The stars may be of equal mass, unequal mass where one star is stronger than the other or be in groups orbiting a central point which doesn't necessarily have to be a star. More information can be found on my dedicated multiple star systems page. The source of the info is Simbad. The file is dated 2000 so any differences between this and any other source will be down to the actual source from where the information came from.


Proper Motion mas/yr
H.D. IdB.D. IdStar CodeMagnitudeR.A.Dec.SpectrumColourYear
187734+03 4172.0A6.70000-17.00000-26.00000K0Orange
B9.400001828

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