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HR 6384 - HD155341 - HIP84311

HR 6384 is a red rotating giant star that can be located in the constellation of Ara. HIP84311 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD155341. HR 6384 has alternative name(s), V829_Ara.

Location of HR 6384

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 HR 6384, the location is 17h 14m 13.40 and -56d53`18.6 .

Proper Motion of HR 6384

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 -006.03 ± 000.26 towards the north and 003.80 ± 000.40 east if we saw them in the horizon.

HR 6384 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 13.0000000 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 HR 6384

HR 6384 has a spectral type of M1/2II/III+A. This means the star is a red giant star. The star has a B-V Colour Index of 1.72 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 3,379 Kelvin.

HR 6384 has been calculated as 65.37 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 45,481,009.94.km.

HR 6384 Apparent and Absolute Magnitudes

HR 6384 has an apparent magnitude of 6.08 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 -1.90 If you used the 2007 Parallax value, you would get an absolute magnitude of -2.29. 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 HR 6384

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 2.54 which gave the calculated distance to HR 6384 as 1284.11 light years away from Earth or 393.70 parsecs. It would take a spaceship travelling at the speed of light, 1284.11 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 2.12 which put HR 6384 at a distance of 1538.51 light years or 471.70 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 HR 6384

The star is a rotating Rotating ellipsoidal 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. HR 6384 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. Its variable/pulsating period lasts for 8.0 days (variability).

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.

HR 6384 Facts

Alternative Names

Traditional NameHR 6384
Short NameV829 Ara
Hipparcos Library I.D.84311
Henry Draper Designation155341

Visual Facts

Star Typegiant star
Absolute Magnitude-1.90 / -2.29
Apparent Magnitude6.08
Right Ascension (R.A.)17h 14m 13.40
Declination (Dec.)-56d53`18.6
1997 Distance from Earth2.54 Parallax (milliarcseconds)
 1284.11 Light Years
 393.70 Parsecs
2007 Revised Distance from Earth2.12 Parallax (milliarcseconds)
 1538.51 Light Years
 471.70 Parsecs
Proper Motion Dec.-6.03 ± 0.26 milliarcseconds/year
Proper Motion RA.3.80 ± 0.40 milliarcseconds/year
B-V Index1.72
Spectral TypeM1/2II/III+A
Colour(M) Red

Variable Star Details

Variable Star ClassRotating
Variable Star TypeRotating ellipsoidal
Mean Variability Period in Days8.000

Estimated Facts

Radius (x the Sun)65.37
Luminosity (x the Sun)13.0000000
Calculated Effective Temperature3,379 Kelvin

Sources and Links

SIMBAD SourceLink

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