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20 Puppis - HD68752 - HIP40259

20 Puppis is a white to yellow luminous giant star that can be located in the constellation of Puppis. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

HIP40259 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD68752. The Id of the star in the Gould Star Catalogue is 269. 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.

20 Puppis has alternative name(s), 20 Puppis , 20 Pup.

Location of 20 Puppis

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 20 Puppis, the location is 08h 13m 19.98 and -15d47`17.6 .

Proper Motion of 20 Puppis

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 -3.35 ± 0.22 miliarcseconds/year towards the north and -12.41 ± 0.30 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of 20 Puppis

20 Puppis has a spectral type of G5Ib/II. This means the star is a white to yellow luminous giant star. The star is 7546.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24612.2859382400000000s. The star has a B-V Colour Index of 1.06 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,845 Kelvin.

20 Puppis Radius has been calculated as being 50.16 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 34,900,258.21.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 35.51. 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 -0.18 with an error value of 0.06 Fe/H with the Sun has a value of 1 to put it into context.

20 Puppis Apparent and Absolute Magnitudes

20 Puppis has an apparent magnitude of 4.99 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 -2.89 If you used the 2007 Parallax value, you would get an absolute magnitude of -2.14. 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 20 Puppis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 2.65 which gave the calculated distance to 20 Puppis as 1230.81 light years away from Earth or 377.36 parsecs. It would take a spaceship travelling at the speed of light, 1230.81 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 3.75 which put 20 Puppis at a distance of 869.77 light years or 266.67 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 7,546.00 Parsecs or 24,612.29 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.

20 Puppis Facts

Alternative Names

Traditional/Proper Name20 Puppis
Short Name20 Pup
Alternative Name(s)20 Puppis
Hipparcos Library I.D.40259
Bonner DurchmusterungBDD-15 2324
Gould I.D.269
Henry Draper Designation68752

Visual Facts

Star Typeluminous giant star
Absolute Magnitude-2.89 / -2.14
Visual / Apparent Magnitude4.99
Naked Eye VisibleYes - Ref: Wiki
Right Ascension (R.A.)08h 13m 19.98
Declination (Dec.)-15d47`17.6
Galactic Latitude10.11 degrees
Galactic Longitude236.63 degrees
1997 Distance from Earth2.65 Parallax (milliarcseconds)
 1230.81 Light Years
 377.36 Parsecs
2007 Revised Distance from Earth3.75 Parallax (milliarcseconds)
 869.77 Light Years
 266.67 Parsecs
Galacto-Centric Distance24,612.29 Light Years / 7,546.00 Parsecs
Proper Motion Dec.-3.35 ± 0.22 milliarcseconds/year
Proper Motion RA.-12.41 ± 0.30 milliarcseconds/year
B-V Index1.06
Radial Velocity16.80 ± 0.30 km/s
Iron Abundance-0.18 ± 0.06 Fe/H
Spectral TypeG5Ib/II
Colour(G) White to Yellow

Estimated Facts

Calculated Effective Temperature4,845 Kelvin

Sources and Links

SIMBAD SourceLink

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