Like a pair of twins, two stars shine prominently within the night skies in February every year. They’re Pollux and Castor within the constellation Gemini the Twins. Pollux, often known as Beta Geminorum, is barely brighter than Castor. It shines with a golden glow whereas Castor seems whiter. Pollux is the 18th brightest star in Earth’s evening sky.
Pollux and Castor are noticeable for being shiny and shut collectively. That’s doubtless how the early stargazers got here to establish them as twins. And it’ll be useful to you, too, once you’re making an attempt to identify these two stars in our evening sky.
Pollux is comparatively near us at 34 light-years away.
You should utilize the easy-to-see constellation Orion to seek out Castor and Pollux, as proven on the chart above.
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One other technique to discover them
There are two good methods to seek out Pollux and Castor. From a Northern Hemisphere location face usually northward to seek out the Big Dipper asterism within the constellation Ursa Main. Draw an imaginary line diagonally by means of the bowl of the Huge Dipper, from the star Megrez by means of the star Merak. You’re going within the path reverse of the Huge Dipper’s deal with.
This line will level to Castor and Pollux.
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Science of Pollux
Pollux is classified as a “K0 IIIb” star. The K0 signifies that it’s considerably cooler than the sun, with a floor colour that may be a mild yellowish orange. Take into account that once you take a look at a star, its colour relies upon considerably on the sensitivity of your eyes, and that colour is troublesome to discern for many level sources.
Pollux is slightly below two instances the mass of our sun. It’s nearly 9 instances the diameter of our sun. And it’s about 30 instances the sun’s brightness in seen mild.
Pollux additionally pumps out an excellent little bit of vitality in non-visible infrared radiation. With all types of radiation counted, Pollux is about 43 instances extra energetic than our sun.
A big planet, no less than 2 instances the mass of Jupiter, was confirmed for Pollux in 2006. The the Worldwide Astronomical Union introduced a correct identify for this planet in 2015: Thestias. At 34 light-years away, Thestias is without doubt one of the nearest of the more than 5,000 recognized exoplanets found to this point.
Thestias strikes round Pollux with a interval of about 590 Earth-days, which is paying homage to Mars’ orbital interval of 687 days. Thestias strikes in a virtually round orbit round its star.
Why Pollux is Beta
As talked about above, Pollux is often known as Beta Geminorum. And the Greek letter Beta is generally reserved for the 2nd-brightest star in a constellation. However Pollux is brighter than its brother star Castor, which is Gemini’s Alpha star. Being so shut collectively within the sky, Castor and Pollux are simple to match. Should you look, you’ll agree. Pollux is brighter.
It’s potential that one or each stars have altered in brightness since German astronomer Johann Bayer assigned the designation about 300 years in the past. Or possibly Bayer typically labeled stars of their order of rising instances? Castor rises sooner than Pollux, as seen from Bayer’s location in Germany. However there’s a geographical dependency right here. From some areas south of the equator, Pollux rises first.
Mythology of Pollux and Castor
There’s a lot mythology related to these two stars, sometimes solely in conjunction with one another. Usually in mythology they’re twins. In Greek mythology, Pollux is immortal, the son of Zeus, and Castor is mortal, the son of King Tyndareus of Sparta.
So that they have been actually half-brothers relatively than true twins, with a typical mom in Queen Leda. Their conception and start was an advanced and unlikely affair, although, with their mom succumbing to each Zeus (disguised as a swan) and King Tyndareus on the identical evening. The ensuing start gave us not solely Castor and Pollux, but in addition their sister, Helen of Troy.
Castor and Pollux are later to have sailed among the many Argonauts with Jason seeking the Golden Fleece. By most accounts, Castor was killed in battle and Pollux couldn’t bear to stay with out him. Pollux begged Zeus to let him die too. Zeus couldn’t grant the reward fairly as requested, since Pollux was a god’s son and subsequently immortal. However Zeus decreed that Pollux would spend each different day in Olympus with the gods, and the remainder of the time within the underworld together with his brother.
To honor the brothers’ devotion, Zeus positioned their constellation within the sky as a remembrance.
The dual stars in different cultures
Whereas in lots of cultures they have been the Twins, in India they have been the Horsemen, and in Phoenicia they have been the 2 gazelles or two kid-goats. Early Christians typically referred to as them David and Jonathan, whereas the early Arabian stargazers knew them as two peacocks.
Maybe probably the most surprising connotation for the twins (together with the remainder of Gemini) was as a “pile of bricks” as reported by Richard Hinckley Allen. Apparently the pile of bricks stood for the inspiration of Rome, and in that context Castor and Pollux have been related to Romulus and Remus, the town’s legendary twin founders.
It’s stated that in China they have been related to Yin and Yang, the contrasts and enhances of life. In all of those instances, they signify two of one thing.
You’ll see why in case you discover these two stars within the evening sky.
Pollux’s place is RA: 7h 45m 20s, dec: +28° 01′ 35″.
Backside line: Pollux, aka Beta Geminorum, is the marginally brighter “twin” of Castor within the constellation Gemini the Twins.
