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Salm (Tau Pegasi) - HD220061 - HIP115250

Salm (Tau Pegasi) is a blue pulsating main sequence dwarf star that can be located in the constellation of Pegasus. It is the 91st brightest star in the night sky. Tau Pegasi is the Bayer Classification for the star. HIP115250 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD220061. Salm has alternative name(s), Salm, Kerb, 62 Pegasi and Markab , tau_Peg, 62 Peg.

Location of Salm

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 Salm, the location is 23h 20m 38.22 and +23d44`25.3 .

Proper Motion of Salm

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 -009.53 ± 000.26 towards the north and 029.45 ± 000.40 east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of Salm

Salm has a spectral type of A5V. This means the star is a blue main sequence dwarf star. The star has a B-V Colour Index of 0.18 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 7,889 Kelvin.

Salm has been calculated as 3.11 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 2,164,381.46.km.

Salm Apparent and Absolute Magnitudes

Salm has an apparent magnitude of 4.58 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 1.03 If you used the 2007 Parallax value, you would get an absolute magnitude of 1.10. 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 Salm

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 19.50 which gave the calculated distance to Salm as 167.26 light years away from Earth or 51.28 parsecs. It would take a spaceship travelling at the speed of light, 167.26 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 20.17 which put Salm at a distance of 161.71 light years or 49.58 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.

Variable Type of Salm

The star is a pulsating Delta Scuti 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. Salm brightness ranges from a magnitude of 5.000 to a magnitude of 5.000 over its variable period. The smaller the magnitude, the brighter the star.

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

Salm Facts

Alternative Names

Traditional NameSalm
Short Nametau Peg, 62 Peg
Bayer DesignationTau Pegasi
Alternative Name(s)Salm, Kerb, 62 Pegasi and Markab
Hipparcos Library I.D.115250
Bonner DurchmusterungBD+22 4810
Henry Draper Designation220061

Visual Facts

Star Typemain sequence dwarf star
Absolute Magnitude1.03 / 1.10
Apparent Magnitude4.58
Right Ascension (R.A.)23h 20m 38.22
Declination (Dec.)+23d44`25.3
1997 Distance from Earth19.50 Parallax (milliarcseconds)
 167.26 Light Years
 51.28 Parsecs
2007 Revised Distance from Earth20.17 Parallax (milliarcseconds)
 161.71 Light Years
 49.58 Parsecs
Proper Motion Dec.-9.53 ± 0.26 milliarcseconds/year
Proper Motion RA.29.45 ± 0.40 milliarcseconds/year
B-V Index0.18
Spectral TypeA5V
Brightest in Night Sky91st
Colour(A) blue

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeDelta Scuti

Estimated Facts

Radius (x the Sun)3.11
Calculated Effective Temperature7,889 Kelvin

Sources and Links

SIMBAD SourceLink

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