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HD 17156, HIP13192

HD 17156 is a white to yellow star that can be located in the constellation of Cassiopeia. The star can not be seen by the naked eye, you need a telescope to see it. It is calculated at being 3.380 Billion Years old. This information comes from ExoPlanet.

HIP13192 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD17156. HD 17156 has at least 2 Extrasolar Planets believed to be in orbit around the star.

Location of HD 17156

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 17156, the location is 02h 49m 44.32 and +71d45`11.9 .

Proper Motion of HD 17156

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 -33.14 ± 0.51 miliarcseconds/year towards the north and 91.14 ± 0.72 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Metallicity, Age, Mass, Radius) of HD 17156

HD 17156 has a spectral type of G5. This means the star is a white to yellow star. The star is 7449.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24295.9074945600000000s. The star has a B-V Colour Index of 0.64 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 5,784 Kelvin.

HD 17156 Radius has been calculated as being 1.69 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,177,321.13.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. The star's solar mass is 1.28 times that of the Sun's. The Sun's Mass is 1,989,100,000,000,000,000,000 billion kg. which to calculate using this website is too large. To give idea of size, the Sun is 99.86% the mass of the solar system.

The star's metallicity is 0.240000, this value is the fractional amount of the star that is not Hydrogen (X) or Helium (Y). An older star would have a high metallicity whereas a new star would have a lower one.

The star is believed to be about 3.38 Billion years old. To put in context, the Sun is believed to be about five billion years old and the Universe is about 13.8 billion years old.

HD 17156 Apparent and Absolute Magnitudes

HD 17156 has an apparent magnitude of 8.17 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 3.70 If you used the 2007 Parallax value, you would get an absolute magnitude of 3.79. 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 17156

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 12.78 which gave the calculated distance to HD 17156 as 255.21 light years away from Earth or 78.25 parsecs. It would take a spaceship travelling at the speed of light, 255.21 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 13.33 which put HD 17156 at a distance of 244.68 light years or 75.02 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 7,449.00 Parsecs or 24,295.91 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 17156 Facts

Alternative Names

Traditional/Proper NameHD 17156
Hipparcos Library I.D.13192
Bonner DurchmusterungBD+71 171
Henry Draper Designation17156

Visual Facts

Star Type star
Age3.38 Billion Years Old
Metalicity0.2400
Absolute Magnitude3.70 / 3.79
Visual / Apparent Magnitude8.17
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)02h 49m 44.32
Declination (Dec.)+71d45`11.9
Galactic Latitude10.99 degrees
Galactic Longitude131.99 degrees
1997 Distance from Earth12.78 Parallax (milliarcseconds)
 255.21 Light Years
 78.25 Parsecs
2007 Revised Distance from Earth13.33 Parallax (milliarcseconds)
 244.68 Light Years
 75.02 Parsecs
Galacto-Centric Distance24,295.91 Light Years / 7,449.00 Parsecs
Proper Motion Dec.-33.14 ± 0.51 milliarcseconds/year
Proper Motion RA.91.14 ± 0.72 milliarcseconds/year
B-V Index0.64
Radial Velocity-3.21 ± 0.23 km/s
Spectral TypeG5
Colour(G) White to Yellow

Companions (Multi-Star and Exoplanets) Facts

Exoplanet Count2

Estimated Facts

Calculated Effective Temperature5,784 Kelvin
Mass Compared to the Sun1.28
Metallicity0.24000

Sources and Links

SIMBAD SourceLink

Related Stars


List of Extrasolar Planets orbiting HD 17156


NameStatusMass (Jupiters)Orbital Period (Days)EccentricityDiscoveredSemi-Major AxisPeriastronInclination
Hd 17156 BConfirmed3.19521.2160.676820070.1623122.00087.000
Hd 17156 CUnconfirmed0.063111.3140.13620080.481

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