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72 Tauri - HD28149 - HIP20789

72 Tauri is a blue main sequence dwarf star that can be located in the constellation of Taurus. HIP20789 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD28149. 72 Tauri has alternative name(s), 72 Tauri , 72 Tau.

Location of 72 Tauri

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 72 Tauri, the location is 04h 27m 17.45 and +22d59`46.9 .

Proper Motion of 72 Tauri

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 -014.46 ± 000.23 towards the north and -000.71 ± 000.34 east if we saw them in the horizon.

72 Tauri 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 140.0000000 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 72 Tauri

72 Tauri has a spectral type of B7V. This means the star is a blue main sequence dwarf star. The star has a B-V Colour Index of -0.09 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 11,375 Kelvin.

72 Tauri has been calculated as 2.39 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,665,271.01.km.

72 Tauri Apparent and Absolute Magnitudes

72 Tauri has an apparent magnitude of 5.53 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 0.01 If you used the 2007 Parallax value, you would get an absolute magnitude of 0.21. 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 72 Tauri

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 7.86 which gave the calculated distance to 72 Tauri as 414.97 light years away from Earth or 127.23 parsecs. It would take a spaceship travelling at the speed of light, 414.97 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 8.63 which put 72 Tauri at a distance of 377.94 light years or 115.87 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.

72 Tauri Facts

Alternative Names

Traditional Name72 Tauri
Short Name72 Tau
Alternative Name(s)72 Tauri
Hipparcos Library I.D.20789
Bonner DurchmusterungBD+22 699
Henry Draper Designation28149

Visual Facts

Star Typemain sequence dwarf star
Absolute Magnitude0.01 / 0.21
Apparent Magnitude5.53
Right Ascension (R.A.)04h 27m 17.45
Declination (Dec.)+22d59`46.9
1997 Distance from Earth7.86 Parallax (milliarcseconds)
 414.97 Light Years
 127.23 Parsecs
2007 Revised Distance from Earth8.63 Parallax (milliarcseconds)
 377.94 Light Years
 115.87 Parsecs
Proper Motion Dec.-14.46 ± 0.23 milliarcseconds/year
Proper Motion RA.-0.71 ± 0.34 milliarcseconds/year
B-V Index-0.09
Spectral TypeB7V
Colour(B) blue

Estimated Facts

Radius (x the Sun)2.39
Luminosity (x the Sun)140.0000000
Calculated Effective Temperature11,375 Kelvin

Sources and Links

SIMBAD SourceLink

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