Psi Capricorni is a blue to white main sequence dwarf star that can be located in the constellation of Capricornus. The description is based on the spectral class. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it. The star has an estimated age of 1.40 Billion of Years but could be as young as 0.90 to 2.00 according to Hipparcos.
Psi Capricorni (Psi Cap) is the Bayer Classification for the star. The Id of the star in the Yale Bright Star Catalogue is HR7936. HIP102485 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD197692. The Gliese ID of the star is GL 805. The star was part of the original catalogue devised by German Astronomer Wilheim Gliese of stars located within 20 parsecs of Earth. Star Names
Flamsteed designations are named after the creator, Sir John Flamsteed. Sir John numbered the stars in the constellation with a number and the latin name, this star's Flamsteed designation is 16 Capricorni with it shortened to 16 Cap.
More details on star alternative names can be found at Star Names .
The location of the star in the night sky 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 Psi Capricorni, the location is 20h 46m 05.77 and -25° 16` 13.9 .
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 -156.56 ± 0.12 miliarcseconds/year towards the north and -51.96 ± 0.27 miliarcseconds/year east if we saw them in the horizon. The Radial Velocity, that is the speed at which the star is moving away/towards us is 25.60000 km/s with an error of about 0.70 km/s .
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 4.05 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.
Psi Capricorni has a spectral type of F5V. This means the star is a blue to white main sequence dwarf star. The star is 7,389.00 Parsecs from the Galactic Centre or terms of Light Years is 24,100.21 s. The star has a B-V Colour Index of 0.42 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 6,635 Kelvin.
Psi Capricorni Radius has been calculated as being 1.55 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,075,656.43.km. If you need the diameter of the star, you just need to multiple the radius by 2. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 1.55. 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 -0.02 with an error value of 0.01 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 1.40 Billion years old but could be between 0.90 and 2.00 Billion years old. In comparison, the Sun's age is about 4.6 Billion Years Old.
Psi Capricorni has an apparent magnitude of 4.13 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 3.30 If you used the 2007 Parallax value, you would get an absolute magnitude of 3.30. 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.
Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 68.16 which gave the calculated distance to Psi Capricorni as 47.85 light years away from Earth or 14.67 parsecs. It would take a spaceship travelling at the speed of light, 47.85 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 68.13 which put Psi Capricorni at a distance of 47.87 light years or 14.68 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*.
|Primary / Proper / Traditional Name||Psi Capricorni|
|Alternative Names||Psi Cap, HD 197692, HIP 102485, HR 7936, 16 Capricorni, 16 Cap, Gliese 805|
|Multiple Star System||No / Unknown|
|Star Type||main sequence Dwarf Star|
|Colour||blue to white|
|Age||1.40 Billion Years Old|
|Age Range||0.90 - 2.00 Billion Years Old|
|Absolute Magnitude||3.30 / 3.30|
|Visual / Apparent Magnitude||4.13|
|Naked Eye Visible||Yes - Magnitudes|
|Right Ascension (R.A.)||20h 46m 05.77|
|Declination (Dec.)||-25° 16` 13.9|
|Galactic Latitude||-35.50 degrees|
|Galactic Longitude||20.00 degrees|
|1997 Distance from Earth||68.16 Parallax (milliarcseconds)|
|47.85 Light Years|
|2007 Distance from Earth||68.13 Parallax (milliarcseconds)|
|47.87 Light Years|
|Galacto-Centric Distance||24,100.21 Light Years / 7,389.00 Parsecs|
|Proper Motion Dec.||-156.56 ± 0.12 milliarcseconds/year|
|Proper Motion RA.||-51.96 ± 0.27 milliarcseconds/year|
|Radial Velocity||25.60 ± 0.70 km/s|
|Iron Abundance||-0.02 ± 0.01 Fe/H|
|Stellar Luminosity (Lsun)||4.05|
|Calculated Effective Temperature||6,635 Kelvin|