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Pi Piscis Austrini, HD217792, HIP113860

Pi Piscis Austrini is a blue main sequence dwarf star that can be located in the constellation of PiscisAustrinus. Pi Piscis Austrini is the brightest star in Piscis Austrinus based on the Hipparcos 2007 apparent magnitude. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

Pi Piscis Austrini is the Bayer Classification for the star. HIP113860 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD217792. The Gliese ID of the star is Gliese GL886.2. The star was part of the original catalogue devised by German Astronomer Wilheim Gliese of stars located within 20 parsecs of Earth. Ref : Star Names.

Location of Pi Piscis Austrini

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 Pi Piscis Austrini, the location is 23h 03m 29.76 and -34d44`58.6 .

Proper Motion of Pi Piscis Austrini

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 84.55 ± 0.46 miliarcseconds/year towards the north and 71.46 ± 0.73 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of Pi Piscis Austrini

Pi Piscis Austrini has a spectral type of A9V. This means the star is a blue main sequence dwarf star. The star is 7388.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24096.9478547200000000s. The star has a B-V Colour Index of 0.3 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 7,218 Kelvin.

Pi Piscis Austrini Radius has been calculated as being 1.61 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,123,378.72.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 1.66. 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 0.12 with an error value of 9.99 Fe/H with the Sun has a value of 1 to put it into context.

Pi Piscis Austrini Apparent and Absolute Magnitudes

Pi Piscis Austrini has an apparent magnitude of 5.12 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 2.84 If you used the 2007 Parallax value, you would get an absolute magnitude of 2.78. 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 Pi Piscis Austrini

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 34.98 which gave the calculated distance to Pi Piscis Austrini as 93.24 light years away from Earth or 28.59 parsecs. It would take a spaceship travelling at the speed of light, 93.24 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 33.99 which put Pi Piscis Austrini at a distance of 95.96 light years or 29.42 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 7,388.00 Parsecs or 24,096.95 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.

Pi Piscis Austrini Facts

Alternative Names

Bayer DesignationPi Piscis Austrini
Hipparcos Library I.D.113860
Gliese ID886.2
Henry Draper Designation217792

Visual Facts

Star Typemain sequence dwarf star
Absolute Magnitude2.84 / 2.78
Visual / Apparent Magnitude5.12
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)23h 03m 29.76
Declination (Dec.)-34d44`58.6
Galactic Latitude-65.72 degrees
Galactic Longitude7.99 degrees
1997 Distance from Earth34.98 Parallax (milliarcseconds)
 93.24 Light Years
 28.59 Parsecs
2007 Revised Distance from Earth33.99 Parallax (milliarcseconds)
 95.96 Light Years
 29.42 Parsecs
Galacto-Centric Distance24,096.95 Light Years / 7,388.00 Parsecs
Proper Motion Dec.84.55 ± 0.46 milliarcseconds/year
Proper Motion RA.71.46 ± 0.73 milliarcseconds/year
B-V Index0.30
Radial Velocity-6.00 ± 4.20 km/s
Iron Abundance0.12 ± 9.99 Fe/H
Eccentricity0.53
Inclination75.76
Semi-Major Axis9.29
Orbital Period (Days)178.32
Argument Of Periastron2.62
Spectral TypeA9V
Colour(A) blue

Estimated Facts

Calculated Effective Temperature7,218 Kelvin

Sources and Links

SIMBAD SourceLink

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