Universe Guide


Gliese 758, HD182488, HIP95319

Gliese 758 is a white to yellow main sequence dwarf star that can be located in the constellation of Lyra. Gliese 758 is the brightest star in Lyra 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. The star has an estimated age of 11.40 Billion of Years but could be as young as 3.30 to 17.20 according to Hipparcos.

HIP95319 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD182488. The Gliese ID of the star is Gliese GL758. The star was part of the original catalogue devised by German Astronomer Wilheim Gliese of stars located within 20 parsecs of Earth. Ref : Star Names. Gliese 758 has at least 1 Extrasolar Planets believed to be in orbit around the star.

Location of Gliese 758

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 Gliese 758, the location is 19h 23m 33.96 and +33d13`17.7 .

Proper Motion of Gliese 758

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 162.32 ± 0.26 miliarcseconds/year towards the north and 83.40 ± 0.35 miliarcseconds/year east if we saw them in the horizon.

Gliese 758 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 1.0000000 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, Age, Radius) of Gliese 758

Gliese 758 has a spectral type of G8V. This means the star is a white to yellow main sequence dwarf star. The star is 7394.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24116.5176553600000000s. The star has a B-V Colour Index of 0.8 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,286 Kelvin.

Gliese 758 Radius has been calculated as being 0.92 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 638,381.51.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 0.93. 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 0.17 with an error value of 0.02 Fe/H with the Sun has a value of 1 to put it into context.

The stars age according to Hipparcos data files put the star at an age of about 11.40 Billion years old but could be between 3.30 and 17.20 Billion years old. In comparison, the Sun's age is about 4.6 Billion Years Old. The reported age is older than the widely recognised age of the Universe so a little scepticism about the age is warranted.

Gliese 758 Apparent and Absolute Magnitudes

Gliese 758 has an apparent magnitude of 6.37 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 5.42 If you used the 2007 Parallax value, you would get an absolute magnitude of 5.38. 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 Gliese 758

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 64.54 which gave the calculated distance to Gliese 758 as 50.54 light years away from Earth or 15.49 parsecs. It would take a spaceship travelling at the speed of light, 50.54 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 63.45 which put Gliese 758 at a distance of 51.40 light years or 15.76 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 7,394.00 Parsecs or 24,116.52 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.

Gliese 758 Facts

Alternative Names

Traditional/Proper NameGliese 758
Hipparcos Library I.D.95319
Bonner DurchmusterungBD+32 3411
Gliese ID758
Henry Draper Designation182488

Visual Facts

Star Typemain sequence dwarf star
Age11.40 Billion Years Old
Age Range3.30 - 17.20 Billion Years Old
Absolute Magnitude5.42 / 5.38
Visual / Apparent Magnitude6.37
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)19h 23m 33.96
Declination (Dec.)+33d13`17.7
Galactic Latitude8.38 degrees
Galactic Longitude66.08 degrees
1997 Distance from Earth64.54 Parallax (milliarcseconds)
 50.54 Light Years
 15.49 Parsecs
2007 Revised Distance from Earth63.45 Parallax (milliarcseconds)
 51.40 Light Years
 15.76 Parsecs
Galacto-Centric Distance24,116.52 Light Years / 7,394.00 Parsecs
Proper Motion Dec.162.32 ± 0.26 milliarcseconds/year
Proper Motion RA.83.40 ± 0.35 milliarcseconds/year
B-V Index0.80
Radial Velocity-21.62 ± 0.07 km/s
Iron Abundance0.17 ± 0.02 Fe/H
Spectral TypeG8V
Colour(G) White to Yellow

Companions (Multi-Star and Exoplanets) Facts

Exoplanet Count1

Estimated Facts

Luminosity (x the Sun)1.0000000
Calculated Effective Temperature5,286 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

List of Extrasolar Planets orbiting Gliese 758

NameStatusMass (Jupiters)Orbital Period (Days)EccentricityDiscoveredSemi-Major AxisPeriastronInclination
Gliese 758 BConfirmed45109000.0000.564200944.844.000

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