North & South Star: Polaris & Sirius

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In summary, Polaris will not always be the North Star. Over a 26,000 year period, Thuban and Vegas will assume the role as the North Star before Polaris resumes its role.
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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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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.
 
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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.
 
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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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1. What is the difference between Polaris and Sirius?

Polaris and Sirius are both stars that can be seen in the night sky, but they have some key differences. Polaris, also known as the North Star, is located close to the north celestial pole and appears stationary in the sky. Sirius, on the other hand, is one of the brightest stars in the sky and can be seen in the constellation Canis Major. It is much closer to Earth than Polaris, making it appear to move slowly across the sky.

2. How do I find Polaris and Sirius in the night sky?

To find Polaris, you can use the "pointer stars" in the Big Dipper constellation. Simply draw a line from the two stars at the end of the Big Dipper's bowl and extend it outwards. Polaris will be the bright star at the end of this line. To find Sirius, look for the constellation Orion and draw a line through its belt stars to Sirius, which is the brightest star in the sky in that direction.

3. Why is Polaris called the North Star?

Polaris is called the North Star because it is located very close to the north celestial pole, which is the point in the sky directly above the Earth's North Pole. This means that as the Earth rotates, Polaris appears to remain stationary in the sky, making it a reliable indicator of north for navigational purposes.

4. Can I see Polaris and Sirius from anywhere on Earth?

Yes, both Polaris and Sirius can be seen from anywhere on Earth, but their visibility may depend on your location and the time of year. Polaris is only visible in the Northern Hemisphere, while Sirius can be seen from both the Northern and Southern Hemispheres.

5. Are Polaris and Sirius important stars in astronomy?

Yes, both Polaris and Sirius are important stars in astronomy. Polaris has been used for navigation since ancient times and is still used for this purpose today. Sirius is also a significant star for astronomers as it is one of the brightest stars in the sky and has been studied for centuries. It is also known to have a binary star companion, making it an interesting target for research and observation.

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