Universe Guide

12 Hydrae - HD74918 - HIP43067

12 Hydrae is a white to yellow giant star that can be located in the constellation of Hydra. HIP43067 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD74918. The Id of the star in the Gould Star Catalogue is 60. 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. 12 Hydrae has alternative name(s), 12 Hydrae , 12 Hya.

Location of 12 Hydrae

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 from celestial equator. The Declination is how up or down compared to the celestial equator and is expressed in degrees. For 12 Hydrae, the location is 08h 46m 22.53 and -13 d 32 ` 51.7 .

Proper Motion of 12 Hydrae

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 -007.00 ± 001.00 towards the north and 016.00 ± 001.00 east if we saw them in the horizon.

12 Hydrae 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 113.0000000 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, Radius) of 12 Hydrae

12 Hydrae has a spectral type of G8III. This means the star is a white to yellow coloured giant star. The star has a B-V Colour Index of 0.9 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,052 Kelvin.

12 Hydrae has been calculated as 11.91 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 8,288,208.27.km.

12 Hydrae Apparent and Absolute Magnitudes

12 Hydrae has an apparent magnitude of 4.32 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 0.05 If you used the 2007 Parallax value, you would get an absolute magnitude of -0.11. 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 12 Hydrae

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 14.00 which gave the calculated distance to 12 Hydrae as 232.97 light years away from us or 71.43 parsecs. In 2007, Hipparcos data was revised with a new parallax of 13.00 which put 12 Hydrae at a distance of 250.89 light years or 76.92 parsecs.

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.

12 Hydrae Facts


Traditional Name12 Hydrae
Short Name12 Hya
Alternative Name(s)12 Hydrae
Hipparcos Library I.D.43067
Gould I.D.60
Henry Draper Designation74918
Celestial TypeStar
Absolute Magnitude0.05 / -0.11
Apparent Magnitude4.32
Right Ascension (R.A.)08h 46m 22.53
Declination (Dec.)-13 d 32 ` 51.7
1997 Distance14.00 Parallax (milliarcseconds)
 232.97 Light Years
 71.43 Parsecs
2007 Distance13.00 Parallax (milliarcseconds)
 250.89 Light Years
 76.92 Parsecs
Proper Motion Dec.-7.00 ± 1.00 milliarcseconds/year
Proper Motion RA.16.00 ± 1.00 milliarcseconds/year
B-V Index0.90
Spectral TypeG8III
Colour(G) White to Yellow
Star Typegiant star
Radius (x the Sun)11.91
Luminosity (x the Sun)113.0000000
Calculated Effective Temperature5,052 Kelvin


Add a Comment


Name:
Email: (Optional)
Comment: