Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Gemini |
Right ascension | 07h 07m 21.271s [2] |
Declination | +22° 42′ 12.75″ [2] |
Apparent magnitude (V) | 6.0 - 14.0 [3] |
Characteristics | |
Evolutionary stage | AGB |
Spectral type | S2,9e-S8,9e(Tc) [3] |
Variable type | mira [3] |
Astrometry | |
Radial velocity (Rv) | −45.2 [4] km/s |
Proper motion (μ) |
RA: −8.765
[2]
mas/
yr Dec.: 0.665 [2] mas/ yr |
Parallax (π) | 1.1795 ± 0.0960 mas [2] |
Distance | 2,800 ± 200
ly (850 ± 70 pc) |
Details | |
Radius | 431 [5] R☉ |
Luminosity | 5,500 [5] L☉ |
Temperature | 2,400 [5] K |
Other designations | |
Database references | |
SIMBAD | data |
R Geminorum (R Gem) is a Mira variable and technetium star in the constellation Gemini. It is located approximately 850 parsecs (2,800 ly) away.
R Geminorum pulsates with an average period of 369.9 days, varying by up to eight magnitudes at visual wavelengths. [3] When at maximum light its apparent visual magnitude is usually between 6 and 7, while at minimum light it is typically near magnitude 14. [7]
R Geminorum is one of the brightest known examples of an S-type star, a type that is similar to M-type star, but whose spectra shows zirconium oxide, yttrium oxide and technetium. [8] These exotic elements are formed in the star's core. Technetium has a half-life of just 4.2 million years, so it must have been brought up from the core relatively recently. R Gem has an unusual amount of it, even for an S-type star. [8]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Gemini |
Right ascension | 07h 07m 21.271s [2] |
Declination | +22° 42′ 12.75″ [2] |
Apparent magnitude (V) | 6.0 - 14.0 [3] |
Characteristics | |
Evolutionary stage | AGB |
Spectral type | S2,9e-S8,9e(Tc) [3] |
Variable type | mira [3] |
Astrometry | |
Radial velocity (Rv) | −45.2 [4] km/s |
Proper motion (μ) |
RA: −8.765
[2]
mas/
yr Dec.: 0.665 [2] mas/ yr |
Parallax (π) | 1.1795 ± 0.0960 mas [2] |
Distance | 2,800 ± 200
ly (850 ± 70 pc) |
Details | |
Radius | 431 [5] R☉ |
Luminosity | 5,500 [5] L☉ |
Temperature | 2,400 [5] K |
Other designations | |
Database references | |
SIMBAD | data |
R Geminorum (R Gem) is a Mira variable and technetium star in the constellation Gemini. It is located approximately 850 parsecs (2,800 ly) away.
R Geminorum pulsates with an average period of 369.9 days, varying by up to eight magnitudes at visual wavelengths. [3] When at maximum light its apparent visual magnitude is usually between 6 and 7, while at minimum light it is typically near magnitude 14. [7]
R Geminorum is one of the brightest known examples of an S-type star, a type that is similar to M-type star, but whose spectra shows zirconium oxide, yttrium oxide and technetium. [8] These exotic elements are formed in the star's core. Technetium has a half-life of just 4.2 million years, so it must have been brought up from the core relatively recently. R Gem has an unusual amount of it, even for an S-type star. [8]