Universe Guide


23 Geminorum - HD46781 - HIP31525

23 Geminorum is a blue to white star that can be located in the constellation of Gemini. HIP31525 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD46781. 23 Geminorum has alternative name(s), 23 Geminorum , 23 Gem.

Location of 23 Geminorum

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 23 Geminorum, the location is 06h 36m 02.12 and +16d47`49.5 .

Proper Motion of 23 Geminorum

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 -029.70 ± 000.33 towards the north and 016.20 ± 000.47 east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of 23 Geminorum

23 Geminorum has a spectral type of F5. This means the star is a blue to white star. The star has a B-V Colour Index of 0.44 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 6,276 Kelvin.

23 Geminorum has been calculated as 2.80 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,949,844.02.km.

23 Geminorum Apparent and Absolute Magnitudes

23 Geminorum has an apparent magnitude of 6.73 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 2.25 If you used the 2007 Parallax value, you would get an absolute magnitude of 2.25. 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 23 Geminorum

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 12.69 which gave the calculated distance to 23 Geminorum as 257.02 light years away from Earth or 78.80 parsecs. It would take a spaceship travelling at the speed of light, 257.02 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 12.72 which put 23 Geminorum at a distance of 256.42 light years or 78.62 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.

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 Stellar Age, Metallicity or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

23 Geminorum Facts

Alternative Names

Traditional Name23 Geminorum
Short Name23 Gem
Alternative Name(s)23 Geminorum
Hipparcos Library I.D.31525
Bonner DurchmusterungBD+16 1210
Henry Draper Designation46781

Visual Facts

Star Type star
Absolute Magnitude2.25 / 2.25
Apparent Magnitude6.73
Right Ascension (R.A.)06h 36m 02.12
Declination (Dec.)+16d47`49.5
1997 Distance from Earth12.69 Parallax (milliarcseconds)
 257.02 Light Years
 78.80 Parsecs
2007 Revised Distance from Earth12.72 Parallax (milliarcseconds)
 256.42 Light Years
 78.62 Parsecs
Proper Motion Dec.-29.70 ± 0.33 milliarcseconds/year
Proper Motion RA.16.20 ± 0.47 milliarcseconds/year
B-V Index0.44
Spectral TypeF5
Colour(F) blue to white

Estimated Facts

Radius (x the Sun)2.80
Calculated Effective Temperature6,276 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Add a Comment

Email: (Optional)