9 lines
732 B
Markdown
9 lines
732 B
Markdown
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name: Ras Algethi (α Her)
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constellation: Her
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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: 2022-02-07 15:21:30.994975
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---
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a bright red star almost on the border with Ophiuchus, a giant whose brightness varies irregularly between 3.1mag and 3.9mag, but often only between 3.3mag and 3.7mag. The period is 90 to 100 days. Suitable comparison stars are ι and κ Ophiuchi, which lie about 6.5 degrees to the southwest and have brightnesses of 4.3mag and 3.2mag, respectively. Alpha Herculis is also a binary whose second fifth-magnitude component, 4.7" away, is visible even in small telescopes with a 6 cm diameter objective. It has a greenish tint that contrasts nicely with the red giant. |