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HD 181342 - HIP95124

HD 181342 is a orange to red giant star that can be located in the constellation of Sagittarius. The star can not be seen by the naked eye, you need a telescope to see it. It is calculated at being 1.800 Billion Years old. This information comes from ExoPlanet.

HIP95124 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD181342. HD 181342 has at least 1 Extrasolar Planets believed to be in orbit around the star.

Location of HD 181342

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 181342, the location is 19h 21m 04.26 and -23d37`10.2 .

Proper Motion of HD 181342

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 -30.58 ± 0.38 miliarcseconds/year towards the north and -45.87 ± 0.61 miliarcseconds/year east if we saw them in the horizon.

HD 181342 Luminosity

Luminosity is the amount of energy that a star pumps out and its relative to the amount that our star, the Sun gives out. The figure of 96.0000000 that I have given is based on the Spectral Types page that I have found on the Internet. You might find a different figure, one that may have been calculated rather than generalised that I have done. The figure is always the amount times the luminosity of the Sun. It is an imprecise figure because of a number of factors including but not limited to whether the star is a variable star and distance.

Physical Properties (Colour, Temperature, Metallicity, Age, Mass, Radius) of HD 181342

HD 181342 has a spectral type of K0III. This means the star is a orange to red giant star. The star is 7298.00000000 Parsecs from the Galactic Centre or terms of Light Years is 23803.4008451200000000s. The star has a B-V Colour Index of 1.02 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,811 Kelvin.

HD 181342 Radius has been calculated as being 4.79 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 3,333,459.06.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 4.60. 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 2.00 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 0.260000, 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 1.80 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 181342 Apparent and Absolute Magnitudes

HD 181342 has an apparent magnitude of 7.55 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 2.24 If you used the 2007 Parallax value, you would get an absolute magnitude of 2.33. 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 181342

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 8.66 which gave the calculated distance to HD 181342 as 376.63 light years away from Earth or 115.47 parsecs. It would take a spaceship travelling at the speed of light, 376.63 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 9.04 which put HD 181342 at a distance of 360.80 light years or 110.62 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 7,298.00 Parsecs or 23,803.40 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 181342 Facts

Alternative Names

Traditional/Proper NameHD 181342
Hipparcos Library I.D.95124
Henry Draper Designation181342

Visual Facts

Star Typegiant star
Age1.80 Billion Years Old
Metalicity0.2600
Absolute Magnitude2.24 / 2.33
Visual / Apparent Magnitude7.55
Naked Eye VisibleRequires a 7x50 Binoculars - Ref: Wiki
Right Ascension (R.A.)19h 21m 04.26
Declination (Dec.)-23d37`10.2
Galactic Latitude-16.73 degrees
Galactic Longitude14.51 degrees
1997 Distance from Earth8.66 Parallax (milliarcseconds)
 376.63 Light Years
 115.47 Parsecs
2007 Revised Distance from Earth9.04 Parallax (milliarcseconds)
 360.80 Light Years
 110.62 Parsecs
Galacto-Centric Distance23,803.40 Light Years / 7,298.00 Parsecs
Proper Motion Dec.-30.58 ± 0.38 milliarcseconds/year
Proper Motion RA.-45.87 ± 0.61 milliarcseconds/year
B-V Index1.02
Radial Velocity-0.84 ± 0.24 km/s
Spectral TypeK0III
Colour(K) Orange to Red

Companions (Multi-Star and Exoplanets) Facts

Exoplanet Count1

Estimated Facts

Luminosity (x the Sun)96.0000000
Calculated Effective Temperature4,811 Kelvin
Mass Compared to the Sun2.00
Metallicity0.26000

Sources and Links

SIMBAD SourceLink

Related Stars


List of Extrasolar Planets orbiting HD 181342


NameStatusMass (Jupiters)Orbital Period (Days)EccentricityDiscoveredSemi-Major AxisPeriastron
Hd 181342 BConfirmed2.9562.0000.120101.65312.000

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