North & South Star: Polaris & Sirius

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SUMMARY

Polaris is currently the North Star, but over a 26,000-year cycle, it will be replaced by Thuban and Vega before returning to prominence. This cycle is influenced by the proper motion of stars, with Polaris gradually moving away from the North Celestial Pole. In contrast, Sirius, the brightest star in the night sky, is drifting southward and will serve as the South Star multiple times in the future. The discussion highlights the significance of precession and proper motion in understanding celestial navigation.

PREREQUISITES
  • Understanding of celestial navigation concepts
  • Familiarity with precession and proper motion of stars
  • Knowledge of the North and South Celestial Poles
  • Basic astronomy terminology
NEXT STEPS
  • Research the effects of precession on star positions over millennia
  • Explore the proper motion of stars using tools like Orbit Simulator
  • Study the historical significance of Thuban and Vega as North Stars
  • Investigate the future role of Sirius as the South Star
USEFUL FOR

Astronomy enthusiasts, educators, and anyone interested in the long-term changes in star positions and their implications for celestial navigation.

tony873004
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Polaris won't always be the North Star. Year by year, it is currently getting closer to the North Celestial Pole. So for our lifetimes and the lifetimes of our children, Polaris will be the North Star. But things start to change for our great-great grandchildren. Over a 26,000 year period, Thuban and Vegas will assume the role as the North Star before Polaris resumes its role. Next time around, Polaris won't be quite as close to the pole as it is now due to proper motion. 26,000 years ago, Polaris was even closer to the pole than it is now.

The Southern Celestial Pole currently has no resident bright star. That too will change. Sirius, the sky's brightest star (besides the Sun), is drifting South and will take a few turns serving as the South Star.
North Celestial Pole:
South Celestial Pole:

https://twitter.com/tony873004/status/721165196035620865
https://twitter.com/tony873004/status/721791747462836224

Movies made using http://orbitsimulator.com/gravitySimulatorCloud/properMotionHome.html
 
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Astronomy news on Phys.org
Thanks for sharing. The simulations are very interesting.
 
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Does this simulation include precession?
 
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DrSteve said:
Does this simulation include precession?
Yes. And it includes proper motion as well.
 
tony873004 said:
Yes. Precession is

Yes. And it includes proper motion as well.
Sorry, that was obvious. It's amazing that Sirius will serendipitously become the Southern Star multiple times. Is the proper motion of Sirius abnormally large, or is it large due to mainly to parallax.
 
DrSteve said:
Sorry, that was obvious. It's amazing that Sirius will serendipitously become the Southern Star multiple times. Is the proper motion of Sirius abnormally large, or is it large due to mainly to parallax.
Lol, you quoted my message before I fixed the typo.

Both. It's very close!

Polaris almost sits still, and as a result, it is the pole star every time the north pole points that direction.

Sirius is on the move. Several 26,000 year periods pass between Sirius' first "term of office" and its second.
 
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That was awesome!
I've never seen the proper motions plotted like that.
It looks like an airport out there. :biggrin:
 
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