Quite right, proper motion is relative to our movement. Anybody else find it incredibly divine a star can line up to celestial North with all this movement going.
Quoting: Anonymous Coward 73466979 Here's "all the movement" of Polaris over about a half century of time. It's just barely detectable in old photographic sky surveys. The high resolution measurements of the proper motion of Polaris come from the 2007 reduction of the Hipparcos data:
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link to www.aanda.org]
The proper motion of Polaris can be independently verified using ground-based telescopes; since proper motion builds up over time, using high resolution images taken decades apart you can see its effect from one image to the next. For example, you can detect the proper motion of Polaris in images from the first and second Palomar Sky Survey that were taken using the same telescope almost 50 years apart. I used the following photographic film plates:
Plate XO001 (A2TX) photographed Aug 22, 1952 5:20 UT
Astrometrically solved image:
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link to nova.astrometry.net]
Plate XJ896 (A2NG) photographed Jan 17, 1998 5:12 UT
Astrometrically solved image:
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link to nova.astrometry.net]
The images 46 years apart should have a total motion of Polaris of about 2.1 arcseconds according to the hipparcos data (44.48 x 11.85 mas = combined vector of 46 milliarcseconds per year = 0.046 arcseconds per year * 46 years = 2.1 arcseconds).
For diffraction centroiding of Polaris, I measured the intersection of the diffraction spikes to find the position of Polaris in each image:
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link to drive.google.com (secure)]
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link to drive.google.com (secure)]
Zooming in on the difference between the intersection points in the diffraction spikes, and drawing a line between those intersection points, you can see that Polaris has moved about 2 arcseconds between 1952 and 1998, just as expected according to the Hipparcos data. And just as expected, the direction of motion is positive in right ascension and negative in declination (resulting in a higher right ascension value and slightly lower declination value in the 1998 image):
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link to drive.google.com (secure)]
So yes, Polaris has proper motion and does move over time, but due to the vast distance between our solar system and Polaris it takes years for these motions to become noticeable even in telescopic images at arcsecond resolution. Even over tens of thousands of years that it takes precession to cycle through, it would only move a fraction of a degree.
