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HR 3643, HD78791, HIP44599

HR 3643 is a blue to white star that can be located in the constellation of Carina. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

The Id of the star in the Yale Bright Star Catalogue is HR3643. HIP44599 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD78791.

Location of HR 3643

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 3643, the location is 09h 05m 08.83 and -72d 36` 09.7 .

Proper Motion of HR 3643

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 -5.26 ± 0.14 miliarcseconds/year towards the north and -8.81 ± 0.15 miliarcseconds/year east if we saw them in the horizon. The Radial Velocity, that is the speed at which the star is moving away/towards us is 22.50000 km/s with an error of about 0.70 km/s .

Physical Properties (Colour, Temperature, Radius) of HR 3643

HR 3643 has a spectral type of F6II-III. This means the star is a blue to white star. The star is 7365.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24021.9302856000000000s. The star has a B-V Colour Index of 0.6 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,895 Kelvin.

HR 3643 Radius has been calculated as being 15.92 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 11,077,263.42.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 14.06. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures. The star's Iron Abundance is -0.04 with an error value of 0.04 Fe/H with the Sun has a value of 1 to put it into context.

HR 3643 Apparent and Absolute Magnitudes

HR 3643 has an apparent magnitude of 4.47 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 -1.25 If you used the 2007 Parallax value, you would get an absolute magnitude of -0.98. 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 3643

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 7.18 which gave the calculated distance to HR 3643 as 454.27 light years away from Earth or 139.28 parsecs. It would take a spaceship travelling at the speed of light, 454.27 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 8.14 which put HR 3643 at a distance of 400.69 light years or 122.85 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.

The star's Galacto-Centric Distance is 7,365.00 Parsecs or 24,021.93 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

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 Metallicity and/or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

HR 3643 Facts

Alternative Names

Traditional/Proper NameHR 3643
Hipparcos Library I.D.44599
Yale Bright Star Catalogue (HR) Id3643
Henry Draper Designation78791

Visual Facts

Star Type star
Absolute Magnitude-1.25 / -0.98
Visual / Apparent Magnitude4.47
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)09h 05m 08.83
Declination (Dec.)-72d 36` 09.7
Galactic Latitude-16.77 degrees
Galactic Longitude287.82 degrees
1997 Distance from Earth7.18 Parallax (milliarcseconds)
 454.27 Light Years
 139.28 Parsecs
2007 Revised Distance from Earth8.14 Parallax (milliarcseconds)
 400.69 Light Years
 122.85 Parsecs
Galacto-Centric Distance24,021.93 Light Years / 7,365.00 Parsecs
Proper Motion Dec.-5.26 ± 0.14 milliarcseconds/year
Proper Motion RA.-8.81 ± 0.15 milliarcseconds/year
B-V Index0.60
Radial Velocity22.50 ± 0.70 km/s
Iron Abundance-0.04 ± 0.04 Fe/H
Spectral TypeF6II-III
Colour(F) blue to white

Estimated Facts

Calculated Effective Temperature5,895 Kelvin

Sources and Links

SIMBAD SourceLink

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