Universe Guide


HD 220689 - HIP115662

HD 220689 is a white to yellow main sequence dwarf star that can be located in the constellation of Aquarius. HIP115662 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD220689. HD 220689 has at least 1 Extrasolar Planets believed to be in orbit around the star.

Location of HD 220689

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 HD 220689, the location is 23h 25m 53.00 and -20d36`56.1 .

Proper Motion of HD 220689

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 -179.33 ± 000.56 towards the north and -015.48 ± 000.70 east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of HD 220689

HD 220689 has a spectral type of G3V. This means the star is a white to yellow main sequence dwarf star. The star has a B-V Colour Index of 0.6 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,895 Kelvin.

HD 220689 has been calculated as 1.15 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 798,686.65.km.

HD 220689 Apparent and Absolute Magnitudes

HD 220689 has an apparent magnitude of 7.74 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 4.46 If you used the 2007 Parallax value, you would get an absolute magnitude of 4.50. 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 HD 220689

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 22.11 which gave the calculated distance to HD 220689 as 147.52 light years away from Earth or 45.23 parsecs. It would take a spaceship travelling at the speed of light, 147.52 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 22.44 which put HD 220689 at a distance of 145.35 light years or 44.56 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.

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.

HD 220689 Facts

Alternative Names

Traditional NameHD 220689
Hipparcos Library I.D.115662
Bonner DurchmusterungBD-21 6419
Henry Draper Designation220689

Visual Facts

Star Typemain sequence dwarf star
Absolute Magnitude4.46 / 4.50
Apparent Magnitude7.74
Right Ascension (R.A.)23h 25m 53.00
Declination (Dec.)-20d36`56.1
1997 Distance from Earth22.11 Parallax (milliarcseconds)
 147.52 Light Years
 45.23 Parsecs
2007 Revised Distance from Earth22.44 Parallax (milliarcseconds)
 145.35 Light Years
 44.56 Parsecs
Proper Motion Dec.-179.33 ± 0.56 milliarcseconds/year
Proper Motion RA.-15.48 ± 0.70 milliarcseconds/year
B-V Index0.60
Spectral TypeG3V
Colour(G) White to Yellow

Companions (Multi-Star and Exoplanets) Facts

Exoplanet Count1

Estimated Facts

Radius (x the Sun)1.15
Calculated Effective Temperature5,895 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

List of Extrasolar Planets orbiting HD 220689

NameStatusMass (Jupiters)Orbital Period (Days)EccentricityDiscoveredSemi-Major AxisPeriastron
Hd 220689 BConfirmed1.062209.0000.1620113.36137.000

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