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25 Sextantis, HD90044, HIP50885, HR4082

25 Sextantis is a blue rotating star that can be located in the constellation of Sextans. 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 HR4082. HIP50885 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD90044.

25 Sextantis has alternative name(s), SS Sex.

Location of 25 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 25 Sextantis, the location is 10h 23m 26.51 and -04d 04` 26.6 .

Proper Motion of 25 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 3.93 ± 0.44 miliarcseconds/year towards the north and -49.42 ± 0.73 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 23.00000 km/s with an error of about 3.40 km/s .

25 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 61000.0000000 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 25 Sextantis

25 Sextantis has a spectral type of B9p Si(CrSr). This means the star is a blue star. The star is 7429.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24230.6748257600000000s. The star has a B-V Colour Index of -0.04 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 11,437 Kelvin.

25 Sextantis Radius has been calculated as being 1.67 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,160,796.34.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 1.62. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

25 Sextantis Apparent and Absolute Magnitudes

25 Sextantis has an apparent magnitude of 5.93 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 0.77 If you used the 2007 Parallax value, you would get an absolute magnitude of 0.84. 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 25 Sextantis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 9.28 which gave the calculated distance to 25 Sextantis as 351.47 light years away from Earth or 107.76 parsecs. It would take a spaceship travelling at the speed of light, 351.47 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 9.60 which put 25 Sextantis at a distance of 339.75 light years or 104.17 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 7,429.00 Parsecs or 24,230.67 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

Variable Type of 25 Sextantis

The star is a rotating Alpha2 Canum Venaticorum 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. 25 Sextantis brightness ranges from a magnitude of 5.934 to a magnitude of 5.906 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 4.4 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 Metallicity and/or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

25 Sextantis Facts

Alternative Names

Traditional/Proper Name25 Sextantis
Flamsteed Name25 Sextantis
Flamsteed Short Name25 Sex
Short NameSS Sex
Hipparcos Library I.D.50885
Yale Bright Star Catalogue (HR) Id4082
Bonner DurchmusterungBD-03 2911
Henry Draper Designation90044

Visual Facts

Star Type star
Absolute Magnitude0.77 / 0.84
Visual / Apparent Magnitude5.93
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)10h 23m 26.51
Declination (Dec.)-04d 04` 26.6
Galactic Latitude42.58 degrees
Galactic Longitude248.32 degrees
1997 Distance from Earth9.28 Parallax (milliarcseconds)
 351.47 Light Years
 107.76 Parsecs
2007 Revised Distance from Earth9.60 Parallax (milliarcseconds)
 339.75 Light Years
 104.17 Parsecs
Galacto-Centric Distance24,230.67 Light Years / 7,429.00 Parsecs
Proper Motion Dec.3.93 ± 0.44 milliarcseconds/year
Proper Motion RA.-49.42 ± 0.73 milliarcseconds/year
B-V Index-0.04
Radial Velocity23.00 ± 3.40 km/s
Spectral TypeB9p Si(CrSr)
Colour(B) blue

Variable Star Details

Variable Star ClassRotating
Variable Star TypeAlpha2 Canum Venaticorum
Mean Variability Period in Days4.381
Variable Magnitude Range (Brighter - Dimmer)5.906 - 5.934

Estimated Facts

Luminosity (x the Sun)61,000.0000000
Calculated Effective Temperature11,437 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

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