9 lines
859 B
Markdown
9 lines
859 B
Markdown
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name: Kastor (α Gem)
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constellation: Gem
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created_by: 8mag
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created_date: 2022-01-21 17:00:00
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updated_by: skybber
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updated_date: 2022-02-06 11:13:09.872387
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---
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Although Pollux is slightly brighter, the Greek alpha letter is Kastor (the 23rd brightest star in the sky). It has a brightness of 1.5mag and is 51 light years from Earth. In addition, it is a known multiple system. The main component has a luminosity of 1.9mag and is 22 times brighter overall than the Sun, with the guide reaching 2.9mag. They orbit each other around a common centre of gravity in 445 years. The pair's angular separation has been quite small in recent years, reaching its minimum of 1.9" in 1970. Since then, it has gradually increased again, so that these blue components can be resolved with a small telescope. In 1985 their distance was 2.6" and by 2017 it had grown to 6". |