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20 Sextantis, HD88697, HIP50100

20 Sextantis is a blue to white star that can be located in the constellation of Sextans. The star can not be seen by the naked eye, you need a telescope to see it. The star has an estimated age of 3.00 Billion of Years but could be as young as 2.40 to 3.50 according to Hipparcos.

20 Sextantis's Alternative Names

HIP50100 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD88697.

Flamsteed designations are named after the creator, Sir John Flamsteed. Sir John numbered the stars in the constellation with a number and the latin name, this star's Flamsteed designation is 20 Sextantis with it shortened to 20 Sex.

BD number is the number that the star was filed under in the Durchmusterung or Bonner Durchmusterung, a star catalogue that was put together by the Bonn Observatory between 1859 to 1903. The star's BD Number is BD-06 3109.

More details on star alternative names can be found at Star Names.

Location of 20 Sextantis

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 Sextantis, the location is 10h 13m 44.49 and -07° 23` 02.7 .

Proper Motion of 20 Sextantis

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 20.11 ± 0.37 miliarcseconds/year towards the north and -191.65 ± 0.60 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 14.80000 km/s with an error of about 0.40 km/s .

20 Sextantis 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 3.0800000 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.

Physical Properties (Colour, Temperature, Age) of 20 Sextantis

20 Sextantis has a spectral type of F8. This means the star is a blue to white star. The star is 7414.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24181.7503241600000000s. The star has a B-V Colour Index of 0.49 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 6,140 Kelvin.

20 Sextantis Radius has been calculated as being 1.44 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,002,337.27.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 1.54. 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 0.06 with an error value of 0.08 Fe/H with the Sun has a value of 1 to put it into context.

The stars age according to Hipparcos data files put the star at an age of about 3.00 Billion years old but could be between 2.40 and 3.50 Billion years old. In comparison, the Sun's age is about 4.6 Billion Years Old.

20 Sextantis Apparent and Absolute Magnitudes

20 Sextantis has an apparent magnitude of 7.21 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 3.79 If you used the 2007 Parallax value, you would get an absolute magnitude of 3.64. 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 Sextantis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 20.70 which gave the calculated distance to 20 Sextantis as 157.57 light years away from Earth or 48.31 parsecs. It would take a spaceship travelling at the speed of light, 157.57 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 19.29 which put 20 Sextantis at a distance of 169.08 light years or 51.84 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 7,414.00 Parsecs or 24,181.75 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.

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20 Sextantis Facts

Visual Facts

Alternative NamesHD 88697, HIP 50100, 20 Sex, BD-06 3109
Star TypeStar
GalaxyMilky Way
Age3.00 Billion Years Old
Age Range2.40 - 3.50 Billion Years Old
Absolute Magnitude3.79 / 3.64
Visual / Apparent Magnitude7.21
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)10h 13m 44.49
Declination (Dec.)-07° 23` 02.7
Galactic Latitude38.55 degrees
Galactic Longitude249.29 degrees
1997 Distance from Earth20.70 Parallax (milliarcseconds)
 157.57 Light Years
 48.31 Parsecs
2007 Revised Distance from Earth19.29 Parallax (milliarcseconds)
 169.08 Light Years
 51.84 Parsecs
Galacto-Centric Distance24,181.75 Light Years / 7,414.00 Parsecs
Proper Motion Dec.20.11 ± 0.37 milliarcseconds/year
Proper Motion RA.-191.65 ± 0.60 milliarcseconds/year
B-V Index0.49
Radial Velocity14.80 ± 0.40 km/s
Iron Abundance0.06 ± 0.08 Fe/H
Semi-Major Axis7430.00
Stellar Luminosity (Lsun)3.08
Spectral TypeF8
Colour(F) blue to white

Estimated Facts

Calculated Effective Temperature6,140 Kelvin

Sources and Links

SIMBAD SourceLink

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