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IhaveaBibledegree t1_ix9zq8u wrote

Reply to comment by Grundyloop in How do astronomers share coordinates with each other? by vaterp

Why not the North Star? Isn’t it a fixed position to our orbital axis?

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Grundyloop t1_ixa0xae wrote

The North Star isn’t on the celestial equator, so it doesn’t have a zero declination. It’s also not exactly aligned with the poles (it’s just under 1 degree off, which is a large offset for precision astronomy).

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Sequels_Shmequals t1_ixai9p1 wrote

Also, FYI the North Star isn't truly fixed either as our rotation axis is processing. The Earth is more accurately like a spinning top. It's a slow change, but in a few 1000 years there won't be a North Star. Or at least it might be a different Star, not Polaris

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lurker1957 t1_ixanm0l wrote

Isn’t it true that Polaris is a really lucky accident as there aren’t any other bright stars along the circle that the precession traces?

Edit: spooling

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Sequels_Shmequals t1_ixaqkya wrote

It is very lucky, but I don't think it's the only bright star. Vega is also quite bright and was once the North Star. But there definitely aren't many bright ones along the circle.

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