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R Geminorum - HD53791 - HIP34356

R Geminorum is a pulsating star that can be located in the constellation of Gemini. HIP34356 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD53791. R Geminorum has alternative name(s), R_Gem.

Location of R 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 R Geminorum, the location is 07h 07m 21.28 and +22d42`12.7 .

Physical Properties (Temperature, Radius) of R Geminorum

R Geminorum has a spectral type of S3,9e. This means the star is a star. The star has a B-V Colour Index of 2.1 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 1,181 Kelvin.

R Geminorum Apparent and Absolute Magnitudes

R Geminorum has an apparent magnitude of 7.53 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 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 R Geminorum

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as -6.22 which gave the calculated distance to R Geminorum as -524.38 light years away from Earth or -160.77 parsecs. It would take a spaceship travelling at the speed of light, -524.38 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.

Variable Type of R Geminorum

The star is a pulsating Omicron Ceti 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. R Geminorum brightness ranges from a magnitude of 11.000 to a magnitude of 7.000 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 370.0 days (variability).

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.

R Geminorum Facts

Alternative Names

Traditional NameR Geminorum
Short NameR Gem
Hipparcos Library I.D.34356
Bonner DurchmusterungBD+22 1577
Henry Draper Designation53791

Visual Facts

Star Type star
Apparent Magnitude7.53
Right Ascension (R.A.)07h 07m 21.28
Declination (Dec.)+22d42`12.7
1997 Distance from Earth-6.22 Parallax (milliarcseconds)
 -524.38 Light Years
 -160.77 Parsecs
B-V Index2.10
Spectral TypeS3,9e

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeOmicron Ceti
Mean Variability Period in Days370.000
Variable Magnitude Range (Brighter - Dimmer)7.000 - 11.000

Estimated Facts

Calculated Effective Temperature1,181 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Multi-Star System

The star has been identified as being a multi-star system, one in which there is at least one star in close orbit to another star or two or more stars orbiting a central point. The stars may be of equal mass, unequal mass where one star is stronger than the other or be in groups orbiting a central point which doesn't necessarily have to be a star. More information can be found on my dedicated multiple star systems page. The source of the info is Simbad. The file is dated 2000 so any differences between this and any other source will be down to the actual source from where the information came from.


Proper Motion mas/yr
H.D. IdB.D. IdStar CodeMagnitudeR.A.Dec.SpectrumColourYear
53791+22 1577.0A15.00000-20.00000PE
B11.400001910

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