Universe Guide


Gliese 673 - HD157881 - HIP85295

Gliese 673 is a orange to red main sequence dwarf star that can be located in the constellation of Ophiuchus. HIP85295 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD157881.

Location of Gliese 673

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 673, the location is 17h 25m 45.57 and +02d06`51.5 .

Proper Motion of Gliese 673

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 -1,184.76 ± 000.37 towards the north and -579.66 ± 000.73 east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of Gliese 673

Gliese 673 has a spectral type of K7V. This means the star is a orange to red main sequence dwarf star. The star has a B-V Colour Index of 1.35 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,241 Kelvin.

Gliese 673 has been calculated as 0.41 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 288,650.13.km.

Gliese 673 Apparent and Absolute Magnitudes

Gliese 673 has an apparent magnitude of 7.54 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 8.10 If you used the 2007 Parallax value, you would get an absolute magnitude of 8.11. 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 673

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 129.54 which gave the calculated distance to Gliese 673 as 25.18 light years away from Earth or 7.72 parsecs. It would take a spaceship travelling at the speed of light, 25.18 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 129.86 which put Gliese 673 at a distance of 25.12 light years or 7.70 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.

Gliese 673 Facts

Alternative Names

Traditional NameGliese 673
Hipparcos Library I.D.85295
Bonner DurchmusterungBD+02 3312
Henry Draper Designation157881

Visual Facts

Star Typemain sequence dwarf star
Absolute Magnitude8.10 / 8.11
Apparent Magnitude7.54
Right Ascension (R.A.)17h 25m 45.57
Declination (Dec.)+02d06`51.5
1997 Distance from Earth129.54 Parallax (milliarcseconds)
 25.18 Light Years
 7.72 Parsecs
2007 Revised Distance from Earth129.86 Parallax (milliarcseconds)
 25.12 Light Years
 7.70 Parsecs
Proper Motion Dec.-1184.76 ± 0.37 milliarcseconds/year
Proper Motion RA.-579.66 ± 0.73 milliarcseconds/year
B-V Index1.35
Spectral TypeK7V
Colour(K) Orange to Red

Estimated Facts

Radius (x the Sun)0.41
Calculated Effective Temperature4,241 Kelvin

Sources and Links

SIMBAD SourceLink

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