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Gamma Doradus, , HD27290, HIP19893

Gamma Doradus is a blue to white giant star that can be located in the constellation of Dorado. Gamma Doradus is the brightest star in Dorado 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.

Gamma Doradus is the Bayer Classification for the star. HIP19893 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD27290. The Gliese ID of the star is Gliese GL167.1. 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.

Gamma Doradus has alternative name(s), gam Dor.

Location of Gamma Doradus

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 Gamma Doradus, the location is 04h 16m 01.49 and -51d29`13.5 .

Proper Motion of Gamma Doradus

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 183.32 ± 0.34 miliarcseconds/year towards the north and 100.79 ± 0.36 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of Gamma Doradus

Gamma Doradus has a spectral type of F4III. This means the star is a blue to white giant star. The star is 7403.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24145.8723563200000000s. The star has a B-V Colour Index of 0.31 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 7,167 Kelvin.

Gamma Doradus Radius has been calculated as being 1.73 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,204,165.88.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 1.74. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

Gamma Doradus Apparent and Absolute Magnitudes

Gamma Doradus has an apparent magnitude of 4.26 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 2.72 If you used the 2007 Parallax value, you would get an absolute magnitude of 2.71. 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 Gamma Doradus

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 49.26 which gave the calculated distance to Gamma Doradus as 66.21 light years away from Earth or 20.30 parsecs. It would take a spaceship travelling at the speed of light, 66.21 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 48.87 which put Gamma Doradus at a distance of 66.74 light years or 20.46 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 7,403.00 Parsecs or 24,145.87 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*. Gamma Doradus brightness ranges from a magnitude of 4.344 to a magnitude of 4.305 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.8 days (variability).

Meteor Showers Radiating from near Gamma Doradus

The Gamma Doradids Meteor Shower radiants from a point near this star. The meteor shower runs typically between 27 Aug- 3 Sep with a peak date of 28-Aug. The speed of a meteor in the shower is 40 Km/s. The amount of meteors predicted to be seen per hour (Zenith Hourly Rate) is 40.

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.

Gamma Doradus Facts

Alternative Names

Short Namegam Dor
Bayer DesignationGamma Doradus
Hipparcos Library I.D.19893
Gliese ID167.1
Henry Draper Designation27290

Visual Facts

Star Typegiant star
Absolute Magnitude2.72 / 2.71
Visual / Apparent Magnitude4.26
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)04h 16m 01.49
Declination (Dec.)-51d29`13.5
Galactic Latitude-44.79 degrees
Galactic Longitude259.84 degrees
1997 Distance from Earth49.26 Parallax (milliarcseconds)
 66.21 Light Years
 20.30 Parsecs
2007 Revised Distance from Earth48.87 Parallax (milliarcseconds)
 66.74 Light Years
 20.46 Parsecs
Galacto-Centric Distance24,145.87 Light Years / 7,403.00 Parsecs
Proper Motion Dec.183.32 ± 0.34 milliarcseconds/year
Proper Motion RA.100.79 ± 0.36 milliarcseconds/year
B-V Index0.31
Radial Velocity25.20 ± 0.50 km/s
Spectral TypeF4III
Colour(F) blue to white

Variable Star Details

Mean Variability Period in Days0.757
Variable Magnitude Range (Brighter - Dimmer)4.305 - 4.344

Estimated Facts

Calculated Effective Temperature7,167 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars


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