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V1817 Cygni - HD184398 - HIP96003

V1817 Cygni is a orange to red eclipsing binary system giant star that can be located in the constellation of Cygnus. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

HIP96003 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD184398.

V1817 Cygni has alternative name(s), V1817_Cyg.

Location of V1817 Cygni

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 V1817 Cygni, the location is 19h 31m 13.56 and +55d43`54.8 .

Proper Motion of V1817 Cygni

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 -18.34 ± 0.28 miliarcseconds/year towards the north and -2.59 ± 0.32 miliarcseconds/year east if we saw them in the horizon.

V1817 Cygni 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 70.0000000 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, Radius) of V1817 Cygni

V1817 Cygni has a spectral type of K2II-IIIcomp. This means the star is a orange to red giant star. The star is 7394.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24116.5176553600000000s. The star has a B-V Colour Index of 1.12 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,628 Kelvin.

V1817 Cygni Radius has been calculated as being 24.90 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 17,322,581.61.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 28.06. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

V1817 Cygni Apparent and Absolute Magnitudes

V1817 Cygni has an apparent magnitude of 6.37 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 -1.17 If you used the 2007 Parallax value, you would get an absolute magnitude of -1.43. 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 V1817 Cygni

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 3.10 which gave the calculated distance to V1817 Cygni as 1052.14 light years away from Earth or 322.58 parsecs. It would take a spaceship travelling at the speed of light, 1052.14 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 2.75 which put V1817 Cygni at a distance of 1186.05 light years or 363.64 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 7,394.00 Parsecs or 24,116.52 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

Variable Type of V1817 Cygni

The star is a eclipsing binary system RS Canum Venaticorum 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. V1817 Cygni brightness ranges from a magnitude of 7.000 to a magnitude of 6.000 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 Metallicity and/or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

V1817 Cygni Facts

Alternative Names

Traditional/Proper NameV1817 Cygni
Short NameV1817 Cyg
Hipparcos Library I.D.96003
Bonner DurchmusterungBDD+55 2215
Henry Draper Designation184398

Visual Facts

Star Typegiant star
Absolute Magnitude-1.17 / -1.43
Visual / Apparent Magnitude6.37
Naked Eye VisibleYes - Ref: Wiki
Right Ascension (R.A.)19h 31m 13.56
Declination (Dec.)+55d43`54.8
Galactic Latitude16.87 degrees
Galactic Longitude87.51 degrees
1997 Distance from Earth3.10 Parallax (milliarcseconds)
 1052.14 Light Years
 322.58 Parsecs
2007 Revised Distance from Earth2.75 Parallax (milliarcseconds)
 1186.05 Light Years
 363.64 Parsecs
Galacto-Centric Distance24,116.52 Light Years / 7,394.00 Parsecs
Proper Motion Dec.-18.34 ± 0.28 milliarcseconds/year
Proper Motion RA.-2.59 ± 0.32 milliarcseconds/year
B-V Index1.12
Radial Velocity-6.38 ± 0.30 km/s
Spectral TypeK2II-IIIcomp
Colour(K) Orange to Red

Variable Star Details

Variable Star ClassEclipsing binary system
Variable Star TypeRS Canum Venaticorum
Variable Magnitude Range (Brighter - Dimmer)6.000 - 7.000

Estimated Facts

Luminosity (x the Sun)70.0000000
Calculated Effective Temperature4,628 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars


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