Universe Guide


50 G. Hya - HD74393 - HIP42854

50 G. Hya is a blue subgiant star that can be located in the constellation of Hydra. HIP42854 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD74393. The Id of the star in the Gould Star Catalogue is 50. 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.

Location of 50 G. Hya

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 50 G. Hya, the location is 08h 43m 59.79 and +04d20`04.5 .

Proper Motion of 50 G. Hya

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 -005.41 ± 000.23 towards the north and -014.95 ± 000.50 east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of 50 G. Hya

50 G. Hya has a spectral type of B9.5III-IV. This means the star is a blue subgiant star. The star has a B-V Colour Index of -0.04 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 10,195 Kelvin.

50 G. Hya has been calculated as 3.60 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 2,503,901.83.km.

50 G. Hya Apparent and Absolute Magnitudes

50 G. Hya 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 -0.40 If you used the 2007 Parallax value, you would get an absolute magnitude of -1.04. 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 50 G. Hya

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 4.42 which gave the calculated distance to 50 G. Hya as 737.93 light years away from Earth or 226.24 parsecs. It would take a spaceship travelling at the speed of light, 737.93 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 3.29 which put 50 G. Hya at a distance of 991.38 light years or 303.95 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.

50 G. Hya Facts

Alternative Names

Traditional Name50 G. Hya
Hipparcos Library I.D.42854
Bonner DurchmusterungBD+04 2029
Gould I.D.50
Henry Draper Designation74393

Visual Facts

Star Typesubgiant star
Absolute Magnitude-0.40 / -1.04
Apparent Magnitude6.37
Right Ascension (R.A.)08h 43m 59.79
Declination (Dec.)+04d20`04.5
1997 Distance from Earth4.42 Parallax (milliarcseconds)
 737.93 Light Years
 226.24 Parsecs
2007 Revised Distance from Earth3.29 Parallax (milliarcseconds)
 991.38 Light Years
 303.95 Parsecs
Proper Motion Dec.-5.41 ± 0.23 milliarcseconds/year
Proper Motion RA.-14.95 ± 0.50 milliarcseconds/year
B-V Index-0.04
Spectral TypeB9.5III-IV
Colour(B) blue

Estimated Facts

Radius (x the Sun)3.60
Calculated Effective Temperature10,195 Kelvin

Sources and Links

SIMBAD SourceLink

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