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Gliese 229, HD42581, HIP29295

Gliese 229 is a red main sequence dwarf star that can be located in the constellation of Lepus. The star can not be seen by the naked eye, you need a telescope to see it.

HIP29295 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD42581. The Gliese ID of the star is Gliese GL229A. 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 229 has at least 2 Extrasolar Planets believed to be in orbit around the star.

Location of Gliese 229

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 229, the location is 06h 10m 34.70 and -21d51`46.5 .

Proper Motion of Gliese 229

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 -713.66 ± 0.67 miliarcseconds/year towards the north and -137.09 ± 0.99 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of Gliese 229

Gliese 229 has a spectral type of M1/M2V. This means the star is a red main sequence dwarf star. The star is 7404.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24149.1339897600000000s. The star has a B-V Colour Index of 1.48 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,025 Kelvin.

Gliese 229 Radius has been calculated as being 0.26 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 181,035.76.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 0.26. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

Gliese 229 Apparent and Absolute Magnitudes

Gliese 229 has an apparent magnitude of 8.15 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 9.34 If you used the 2007 Parallax value, you would get an absolute magnitude of 9.35. 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 229

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 173.19 which gave the calculated distance to Gliese 229 as 18.83 light years away from Earth or 5.77 parsecs. It would take a spaceship travelling at the speed of light, 18.83 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 173.81 which put Gliese 229 at a distance of 18.77 light years or 5.75 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 7,404.00 Parsecs or 24,149.13 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 229 Facts

Alternative Names

Traditional/Proper NameGliese 229
Hipparcos Library I.D.29295
Bonner DurchmusterungBD-21 1377
Gliese ID229A
Henry Draper Designation42581

Visual Facts

Star Typemain sequence dwarf star
Absolute Magnitude9.34 / 9.35
Visual / Apparent Magnitude8.15
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)06h 10m 34.70
Declination (Dec.)-21d51`46.5
Galactic Latitude-18.44 degrees
Galactic Longitude228.61 degrees
1997 Distance from Earth173.19 Parallax (milliarcseconds)
 18.83 Light Years
 5.77 Parsecs
2007 Revised Distance from Earth173.81 Parallax (milliarcseconds)
 18.77 Light Years
 5.75 Parsecs
Galacto-Centric Distance24,149.13 Light Years / 7,404.00 Parsecs
Proper Motion Dec.-713.66 ± 0.67 milliarcseconds/year
Proper Motion RA.-137.09 ± 0.99 milliarcseconds/year
B-V Index1.48
Radial Velocity4.72 ± 0.10 km/s
Spectral TypeM1/M2V
Colour(M) Red

Companions (Multi-Star and Exoplanets) Facts

Exoplanet Count2

Estimated Facts

Calculated Effective Temperature4,025 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars


List of Extrasolar Planets orbiting Gliese 229


NameStatusMass (Jupiters)Orbital Period (Days)EccentricityDiscoveredSemi-Major AxisPeriastron
Gliese 229 A BConfirmed0.10068471.0000.120140.97149.000
Gliese 229 BConfirmed351995

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