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IU Velorum - HD77320 - HIP44213

IU Velorum is a blue eruptive main sequence dwarf star that can be located in the constellation of Vela. HIP44213 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD77320. IU Velorum has alternative name(s), IU_Vel.

Location of IU Velorum

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 IU Velorum, the location is 09h 00m 22.26 and -43d10`26.4 .

Proper Motion of IU Velorum

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 000.92 ± 000.22 towards the north and -008.74 ± 000.26 east if we saw them in the horizon.

IU Velorum 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 1060.0000000 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 IU Velorum

IU Velorum has a spectral type of B3Vne. This means the star is a blue main sequence dwarf star. The star has a B-V Colour Index of -0.15 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 13,674 Kelvin.

IU Velorum has been calculated as 3.16 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 2,195,888.71.km.

IU Velorum Apparent and Absolute Magnitudes

IU Velorum has an apparent magnitude of 6.04 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 -1.39 If you used the 2007 Parallax value, you would get an absolute magnitude of -1.49. 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 IU Velorum

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 3.26 which gave the calculated distance to IU Velorum as 1000.50 light years away from Earth or 306.75 parsecs. It would take a spaceship travelling at the speed of light, 1000.50 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 3.12 which put IU Velorum at a distance of 1045.40 light years or 320.51 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.

Variable Type of IU Velorum

The star is a eruptive Gamma Cassiopeiae variable type which means that its size changes over time. The Variable Type is usually named after the first star of that type to be spotted. IU Velorum brightness ranges from a magnitude of 6.000 to a magnitude of 6.000 over its variable period. The smaller the magnitude, the brighter the star.

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.

IU Velorum Facts

Alternative Names

Traditional NameIU Velorum
Short NameIU Vel
Hipparcos Library I.D.44213
Henry Draper Designation77320

Visual Facts

Star Typemain sequence dwarf star
Absolute Magnitude-1.39 / -1.49
Apparent Magnitude6.04
Right Ascension (R.A.)09h 00m 22.26
Declination (Dec.)-43d10`26.4
1997 Distance from Earth3.26 Parallax (milliarcseconds)
 1000.50 Light Years
 306.75 Parsecs
2007 Revised Distance from Earth3.12 Parallax (milliarcseconds)
 1045.40 Light Years
 320.51 Parsecs
Proper Motion Dec.0.92 ± 0.22 milliarcseconds/year
Proper Motion RA.-8.74 ± 0.26 milliarcseconds/year
B-V Index-0.15
Spectral TypeB3Vne
Colour(B) blue

Variable Star Details

Variable Star ClassEruptive
Variable Star TypeGamma Cassiopeiae

Estimated Facts

Radius (x the Sun)3.16
Luminosity (x the Sun)1,060.0000000
Calculated Effective Temperature13,674 Kelvin

Sources and Links

SIMBAD SourceLink

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