Universe Guide

HomeFactsConstellationsAquarius

HD 220689, HIP115662

HD 220689 is a white to yellow main sequence dwarf star that can be located in the constellation of Aquarius. The star can not be seen by the naked eye, you need a telescope to see it. The star has an estimated age of 7.90 Billion of Years but could be as young as 4.70 to 9.80 according to Hipparcos.

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 ± 0.56 miliarcseconds/year towards the north and -15.48 ± 0.70 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Age, 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 is 7389.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24100.2094881600000000s. 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 Radius has been calculated as being 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. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 1.13. 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 -0.09 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 7.90 Billion years old but could be between 4.70 and 9.80 Billion years old. In comparison, the Sun's age is about 4.6 Billion Years Old.

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.

The star's Galacto-Centric Distance is 7,389.00 Parsecs or 24,100.21 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.

HD 220689 Facts

Alternative Names

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

Visual Facts

Star Typemain sequence dwarf star
Age7.90 Billion Years Old
Age Range4.70 - 9.80 Billion Years Old
Absolute Magnitude4.46 / 4.50
Visual / Apparent Magnitude7.74
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)23h 25m 53.00
Declination (Dec.)-20d36`56.1
Galactic Latitude-69.42 degrees
Galactic Longitude46.76 degrees
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
Galacto-Centric Distance24,100.21 Light Years / 7,389.00 Parsecs
Proper Motion Dec.-179.33 ± 0.56 milliarcseconds/year
Proper Motion RA.-15.48 ± 0.70 milliarcseconds/year
B-V Index0.60
Radial Velocity12.10 ± 0.30 km/s
Iron Abundance-0.09 ± 0.08 Fe/H
Spectral TypeG3V
Colour(G) White to Yellow

Companions (Multi-Star and Exoplanets) Facts

Exoplanet Count1

Estimated Facts

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

Add a Comment


Name:
Email: (Optional)
Comment: