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    Re: Polaris' PM in RA?
    From: Frank Reed
    Date: 2020 Sep 24, 09:47 -0700

    Sean,

    Just a couple of thoughts. You wondered: "The FK5 catalogue agrees with Meeus that Polaris' PM in RA is around 3000 mas/yr. So where did SIMBAD get 44 ... and where did Wiki get 198?"

    I haven't checked anything, but I can't help noticing that 3000 is just about 15×198. So if I had to bet... :) Are there any other cases you can compare?

    You mentioned that you weren't sure what your source was for some of your data. This is a place where a Google search may help. If you have a data line for Polaris listing its RA, Dec, proper motion components, and probably parallax, for example, try sticking that whole line in double quotes and searching for it in Google. There's a fair chance that this will lead you back to your original source since individual data sources usually differ in the low significance digits, and they act like fingerprints. 

    Frank Reed

       
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