Castor is Gemini’s second brightest star and the sky’s 44th brightest star. With a combined apparent magnitude of 1.58, it’s a visual binary. The two components are separated by 6″ and have a 467-year revolution time.
Castor is a four-star system since each component of the Alpha Geminorum system is a spectroscopic double star in and of itself. Castor has a weak companion, an eclipsing binary star system with a period of slightly under a day, around 72″ distant.
The system’s two components are red (class M) dwarfs. Because all six of Castor’s components are gravitationally bonded together, it is classified as a sextuple star system. YY Geminorum is the label for the third component, which is categorized as a variable star.
The major component has a spectral class of A1 V, and the companion is thought to have a spectral type of M5 V. The stellar classifications of the secondary component stars are A2 Vm and M2 V.
Castor orbits the Sun at a distance of 51 light years. It was known as “The Head of the Foremost Twin,” or Al-Ras al-Taum al-Muqadim, in Arabic culture.
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Pollux Geminorum (Beta Geminorum)
Pollux is the brightest star in Gemini and the night sky’s 17th brightest star. It has the star classification K0 III and is an evolved orange giant. It is 33.78 light years away from the solar system and has an apparent magnitude of 1.14.
Beta Geminorum has a mass of twice that of the Sun and a radius of nearly nine times that of the Sun. From the Arabic Al-Ras al-Tau’am al-Mu’akhar, it is also known as “The Head of the Second Twin.”
In June 2006, an extrasolar planet was discovered orbiting the star. Pollux b has a mass of at least 2.3 times that of Jupiter and a 590-day orbital period.
Alhena Geminorum (Gamma Geminorum)
Another brilliant star in Gemini is Alhena, Gamma Geminorum. It is plainly visible to the naked eye, with an apparent magnitude of 1.915. The star is about 109 light years away from the Earth.
Gamma Geminorum is a white subgiant star with a stellar classification of A1 IV. It has a mass of 2.8 solar masses and a radius of 3.3 times that of the Sun. It has a dazzling output of around 123 times that of the Sun.
Alhena is the star’s traditional name, which is derived from the Arabic word Al Han’ah, which means “beautiful.” “the brand,” he said, alluding to the camel’s neck brand. It’s also known as Almeisan, which comes from the Arabic word Al Maisan, which means “to eat.” “The gleaming one.”
Mebsuta Geminorum (Epsilon Geminorum)
Castor’s outstretched right leg is marked with Epsilon Geminorum. It’s a supergiant that belongs to the G8 Ib spectral class. It is about 840 light years away and has an apparent magnitude of 3.06.
The star is nearly 8,500 times brighter and has 19 times the mass of the Sun. The radius of the star is approximately 105-175 times that of the Sun.
The traditional name of Epsilon Geminorum is Mebsuta, which originates from the ancient Arabic Mabsah, which means “the spread paw.” The paws of a lion were represented as Epsilon and Zeta Geminorum in Arabic culture. Melboula or Melucta are other names for Epsilon Geminorum.
The star is close to the ecliptic, and the Moon and planets sometimes obscure it.
Tejat Posterior Geminorum (Mu Geminorum)
Mu Geminorum is the Gemini constellation’s fourth brightest star. It is around 230 light years away and has a visual magnitude of 2.857. The star is classified as a red giant, with a spectral class of M3 III. It’s also known as a type LB slow irregular variable. It has luminosity changes between magnitude 2.75 and 3.02 over a 72-day period, with a long-term variation period of 2,000 days.
Tejat Posterior is the star’s traditional moniker “Castor’s foot is referred to as “the rear foot.” It’s also known by another Latin word, Calx, which means “beautiful.” “The back of the heel.”
Tejat Prior Geminorum (Eta Geminorum)
Eta Geminorum is a multiple star 350 light years away from Earth. A spectroscopic binary star and a class G0 dwarf star orbit the pair with a period of over 700 years make up the system.
The binary system’s main component is a semi-regular variable star that has brightness fluctuations over a 234-day period. It’s a red giant with the M3IIIlab spectral classification. Its brightness varies between 3.15 and 3.9 magnitudes. The secondary star has a spectral type of B and has an orbital period of 8.2 years around the red giant.
Eta Geminorum is near the ecliptic and can be occulted by the Moon and, on rare occasions, a planet.
Alzirr Geminorum (Xi Geminorum)
Xi Geminorum is a yellow-white subgiant star in the spectral class F5 IV, with a brightness of around 11 times that of the Sun. It is 58.7 light years away from Earth and has an apparent magnitude of 3.35. With an estimated rotational velocity of 66 km/s, the star is a fast rotator. It’s possible that it’s a spectroscopic binary.
Alzirr is the star’s given name, which means “the button” in Arabic. It represents one of the Gemini twins’ four feet. It’s bright enough that you won’t need binoculars to see it.
Wasat Geminorum (Delta Geminorum)
Delta Geminorum is also bright enough to be seen without the use of a telescope. It is roughly 60.5 light years away and has a visual magnitude of 3.53. It is classified as a yellow-white subgiant star with the stellar classification F0 IV.
Wasat, the star’s traditional name, is Arabic for “middle.” Ta Tsun, the star’s Chinese name, is also used to refer to it.
Wasat, which is two-tenths of a degree south of the ecliptic, is occasionally occulted by the Moon and far less frequently by planets. Clyde Tombaugh, an American astronomer, discovered Pluto in 1930, only 0.5 east of the star.
Wasat has an estimated rotational velocity of 129.7 km/s, making it a very rapid rotator. Its age is estimated to be around 1.6 billion years. The star will pass within 6.7 light years of the Sun in 1.1 million years.
Delta Geminorum is a triple star system in reality. The system’s inner stars form a spectroscopic binary, with components orbiting each other with a 6.1-year period. In a small telescope, the binary system features a class K companion that orbits the primary component with a period of 1,200 years and can be viewed.
Geminorum (Kappa Geminorum)
Another multiple star in Gemini is Kappa Geminorum. It is around 143 light years away from the solar system and has the star classification G8 IIIa. The star shines 78 times brighter than the Sun. The apparent magnitude of the object is 3.57.
Geminorum (Lambda Geminorum)
Lambda Geminorum is a variable star that belongs to the spectral class A3 V. It is 94.3 light years away and has an apparent magnitude of 3.58. It is 28 times brighter than the Sun, has a radius of 2.8 times that of the Sun, and a mass of 2.1 times that of the Sun.
Propus Geminorum (Iota Geminorum)
The fourth magnitude star Iota Geminorum belongs to the spectral class G9III. It is roughly 326 light years away and has an apparent magnitude of 3.78.
Propus, the star’s given name, is Latin meaning “forefoot.” Propus is a variable star, which means it can change its appearance.
Mekbuda Geminorum (Zeta Geminorum)
Mekbuda, Zeta Geminorum, is a variable star with an intermediate luminosity that is categorized as a Classical Cepheid, or Population I Cepheid, after Delta Cephei, the star that serves as the prototype for this class of variations. Delta Cephei variables are 4-20 times more massive and up to 100,000 times more luminous than the Sun. They are typically yellow supergiants in the spectral class F6-K2, with brightness changes caused by pulsation durations ranging from a few days to months.
Like all stars in its class, Zeta Geminorum has a consistent pulsation frequency that is determined by the star’s mass. Its luminosity varies from magnitude 3.68 to 4.16 during a period of 10.148 days. The star is almost 2,900 times brighter than the Sun.
Mekbuda, the star’s given name, is derived from ancient Arabic and means “lion’s folded paw.”
Geminorum (Tau Geminorum)
Tau Geminorum is an orange giant that belongs to the K2 III star classification. It is about 321 light years away from the solar system and has an apparent magnitude of 4.42. Under ideal conditions, the star can be seen without binoculars.
Tau Geminorum is twice the mass of the Sun and has a radius of 27 times that of the Sun. It is approximately 224 times brighter.
Tau Geminorum b, a brown dwarf with 18.1 Jupiter masses, is the star’s companion. The dwarf star, found in 2004, completes an orbit around the main star in 305 days.
U Geminorum
U Geminorum is a dwarf nova in the constellation Gemini. It’s a binary star consisting of a white dwarf around a red dwarf star. The star undergoes an outburst every 100 days or so, resulting in a dramatic rise in luminosity. When the star experienced one of its outbursts, English astronomer John Russell Hind identified the system in 1855.
The orbital period of the two dwarfs is 4 hours and 11 minutes, which is extremely short and one of the reasons why U Geminorum is a variable star. With each revolution, the stars pass in front of each other. The system’s apparent magnitude usually ranges between 14.0 to 15.1, but during an outburst, it can reach 9th magnitude, making it 100 times brighter. The duration is quite variable, ranging from 62 to 257 days.
What is the brightest star in Gemini?
Pollux is the brightest star in Gemini, and Castor is the second brightest. When Johann Bayer gave his eponymous designations in 1603, he did not precisely discern which of the two was the brighter, resulting in Castor’s Bayer designation of “Alpha.” Although mythological heroes are twins, the stars themselves are physically extremely different.
Gem (Castor) is a sextuple star system 52 light-years from Earth that appears to the naked eye as a magnitude 1.6 blue-white star. At magnitudes 1.9 and 3.0, two spectroscopic binaries with a period of 470 years may be seen. The system also includes a wide-set red dwarf star, which is an Algol-type eclipsing binary star with a period of 19.5 hours, a minimum brightness of 9.8 and a maximum magnitude of 9.3.
Gem (Pollux) is a large orange star with a magnitude of 1.14 that is 34 light-years away from Earth. Pollux, like two other stars in Gemini, HD 50554 and HD 59686, has an extrasolar planet orbiting it.
Gem (Alhena) is a 1.9 magnitude blue-white star located 105 light-years from Earth.
Gem (Wasat) is a 59 light-year binary star with a lengthy period. The main is a magnitude 3.5 white star, whereas the secondary is a magnitude 8.2 orange dwarf star. The time span is over 1000 years, and it may be divided by medium amateur telescopes.
Gem (Mebsuta), a twin star nine hundred light-years from Earth, contains a main yellow supergiant of magnitude 3.1. Binoculars and small telescopes can see the optical companion, which has a magnitude of 9.6.
Gem (Mekbuda) is a double star, the primary of which is a Cepheid variable star with a period of 10.2 days with magnitudes of 4.2 and 3.6. It’s a yellow supergiant that’s 1,200 light-years away from Earth and has a radius of 60 times that of the Sun, making it roughly 220,000 times the size of the Sun. Binoculars and tiny amateur telescopes can see the companion, a magnitude 7.6 star.
The binary star Gem (Propus) has a variable component. It’s 380 light-years away, has a 500-year cycle, and can only be seen with large amateur telescopes. The primary is a 233-day-old semi-regular red giant with a minimum magnitude of 3.9 and a maximum magnitude of 3.1. The magnitude of the secondary is 6.
Gem is a binary star located 143 light years away from Earth. The main is a 3.6 magnitude yellow giant, while the secondary is a magnitude 8. Because of the brightness difference, the two are only divisible in bigger amateur instruments.
In binoculars and small amateur telescopes, v Gem is a double star. The main is a magnitude 4.1 blue giant 550 light-years from Earth, and the secondary is a magnitude 8 blue giant.
38 Gem, a double star 84 light-years from Earth, is also divisible in modest amateur telescopes. The main is a magnitude 4.8 white star, whereas the secondary is a magnitude 7.8 yellow star.
J. R. Hind found U Gem, a dwarf nova type cataclysmic variable, in 1855.
The Bayer designation for a star in the northern constellation of Gemini is Mu Gem (Tejat). Because it is the foot of Castor, one of the Gemini twins, it has the traditional name Tejat Posterior, which means back foot.
What are the three brightest stars in the constellation Gemini?
There are 85 stars visible with the naked eye in the Gemini constellation. Not to mention the fact that Gemini has ten officially recognized stars. The International Astronomical Union (IAU) has authorized the star names Alhena, Alzirr, Castor, Jishui, Mebsuta, Mekbuda, Pollux, Propus, Tejat, and Wasat. Pollux, or Beta Geminorum, is the brightest star in Gemini. Pollux is the night sky’s 17th brightest star. Pollux, interestingly, has a planet around it. The second brightest star in the Gemini constellation is Castor, or Alpha Geminorum, a magnitude 1.6 blue-white star that is actually a sextuple star system 52 light years away from our planet.
You may already be aware that the brightest star in a constellation is designated as “Alpha.” So, what’s the matter with Gemini? The answer dates back to 1603, when Johann Bayer, a German uranographer, was unable to determine whether of the two stars, Castor or Pollux, was brighter.
Other bright stars can be found in the constellation Gemini, in addition to the twins Castor and Pollux.
- Alhena, also known as Gamma Geminorum, is a blue-white star 105 light years away from the Sun with a magnitude of 1.9.
- Wasat, also known as Delta Geminorum, is a binary star that orbits the Sun at a distance of 59 light years.
- Mebsuta, also known as Epsilon Geminorum, is a double star consisting of a yellow supergiant with a magnitude of 3.1 and an optical companion with a brightness of 9.6.
What is Gemini’s third brightest star?
Many intriguing stars can be found in Gemini’s constellation, but the stars Pollux and Castor, with Pollux being the brightest, dominate the constellation.
Pollux
With an apparent magnitude of 1.14, Pollux, also known as Beta Geminorum, is the 18th brightest star in the night sky and the brightest in Gemini.
Pollux is an orange-hued evolved giant star that is the closest massive star to our Sun, at only 33.78 light-years away from our Solar System.
Pollux has 191 percent the mass of our Sun, has a radius of 906 percent that of our Sun, and is 32.7 times brighter. Pollux is actually cooler than our Sun, with temperatures of roughly 4,586 K, despite its great exploits.
Since 1943, the spectra of Pollux has been used to classify other stars as one of the stable anchor points. Pollux b, a verified exoplanet orbiting the massive star, was discovered in 2006.
Pollux b has a mass of approximately 2.3 times that of Jupiter. It takes 590 days to orbit the massive star. Pollux and Castor have been associated with many things throughout history, including Yin and Yang, two gazelles, two-kid goats, the founding brothers of Rome, Romulus and Regulus, and so on.
Pollux is the sole star from Gemini among the 58 stars chosen for celestial navigation. The winter asterism known as the Winter Circle or Winter Hexagon includes Pollux, Capella, Aldebaran, Sirius, and Procyon.
Castor
Castor, commonly known as Alpha Geminorum, is the second-brightest star in the constellation Gemini, located 51 light-years from Earth. The apparent magnitude of Castor is 1.93.
Castor is a multi-star system with approximately six members confirmed. Two A-class main-sequence stars with red dwarf partners are the most notable.
Alpha Geminorum Aa has roughly 276 percent of our Sun’s mass, 240 of its radius, and temperatures of around 10,286 K, making it twice as hot as our Sun. Alpha Geminurom Ba is the system’s biggest star, with a mass of 298 percent that of our Sun, a radius of 330 percent that of our Sun, and surface temperatures of 8,842 K.
Alhena
Alhena, also known as Gamma Geminorum, is a blue evolving star that is the third brightest star in the constellation Gemini and is about 109 light-years away.
Alhena is 123 times brighter than our Sun, with an apparent magnitude of 1.9. This star’s hydrogen reserves have run out, and it has entered the subgiant stage.
Alhena contains 281 percent of the mass of our Sun, 330 percent of its radius, and is extremely hot, with surface average temperatures of 9,260 K.
Wasat
Wasat, also known as Delta Geminorum, is a triple star system in Gemini that consists of a subgiant star, a colder K-type companion, and a third star that has yet to be resolved.
Wasat has a combined visual magnitude of +3.53, with the central star containing 157 percent of the mass of our Sun and temperatures of roughly 6,900 K. Wasat is approximately 60.5 light-years distant.
Mebsuta
Mebsuta, also known as Epsilon Geminorum, is a yellow supergiant star around 840 light-years from Earth. It has a magnitude of +3.06 on the apparent scale.
Mebsuta is truly massive, with a mass of roughly 1,920 percent that of our Sun, a radius of 14,000 percent that of our Sun, and a brightness of 8,500 times that of our Sun.
Mekbuda
Mekbuda, also known as Zeta Geminorum, is a brilliant classical Cepheid variable star with an apparent magnitude of 3.93 and a period of 10.148 days, fluctuating from 3.68 to 4.16.
Mekbuda is approximately 1,120 light-years away from Earth. This star is roughly 770 percent the mass of our Sun, has a radius of 6,524 percent that of our Sun, and is 2,900 times brighter overall.
Propus
Propus, also known as Eta Geminorum, is a triple star system in the constellation Gemini that is about 700 light-years away from Earth. The apparent magnitude of this system is 3.15.
Propus Aa, the primary star, is a highly developed cool brilliant star with roughly 250 percent the mass of our Sun, a radius of 31,400 percent that of our Sun, and a brightness of 12,823 times that of our Sun.
Tejat
With an apparent magnitude of 2.857, Tejat, also known as Mu Geminorum, is the fourth brightest star in Gemini. This massive star is roughly 230 light-years away from us.
Tejat is 1,148 times brighter than our Sun, with 210 percent of its mass, 8,000 percent of its radius, and 210 percent of its mass. The star is cooler than our Sun due to its size, with temperatures of roughly 3,460 K.
Kappa Geminorum
Kappa Geminorum is a binary star system in the constellation Gemini, around 141 light-years from Earth. The primary star is a 3.568 magnitude star, whereas the secondary star is an eight magnitude star.
Kappa Geminorum has a mass of roughly 207 percent that of our Sun, a radius of 1,100 percent that of our Sun, and is 67.6 times brighter. Its spectra has served as one of the steady reference points for classifying other stars since 1943.
Nu Geminorum
Nu Geminorum is a binary and potentially multiple star system in the constellation Gemini, approximately 540 light-years distant. It has a magnitude of 4.16 on the apparent scale.
Nu Geminorum Aa, the parent star, has around 640 percent the mass of our Sun, is 1,1380 times brighter, and nearly three times as hot, at temperatures of around 14,100 K. Nu Geminorum Ab is currently unknown save for the fact that it has a mass of roughly 460 percent that of our Sun.
Geminorum
38 Geminorum, also known as e Geminorum, is a Gemini binary star whose primary star, A, is roughly 96 light-years away and B is around 97.9 light-years away.
A has an apparent magnitude of 4.75, while B has an apparent magnitude of 7.80. The primary star is an A-type main-sequence star with a mass of roughly 155 percent that of our Sun, as well as a chemically unusual star.
The secondary star is a G-type main-sequence star that is 89 percent smaller than our Sun in mass and radius.
U Geminorum is a binary star system in which a white dwarf orbits a red dwarf very tightly. A dwarf nova is the typical example.
U Geminorum is around 304.5 light-years away from us, with an apparent magnitude of 8.2 for the primary component and 14.9 for the secondary.
Because the two components orbit each other every 4 hours and 11 minutes, their brightness varies owing to eclipses. The largest component is the white dwarf, which has 120 percent of the mass of our Sun but only 0.008 of its radius. However, it is 5 times hotter than our Sun, with temperatures of roughly 29,200 K.
The companion red dwarf is also much smaller than our Sun, with only 42% of its mass and a radius of roughly 43% of our Sun’s.
