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    Re: Motions of the stars seen from the equator
    From: David Pike
    Date: 2025 Nov 15, 15:28 -0800

    Frank Reed wrote:

     Three days ago, I wrote:

    "I'm surprised you haven't had an answer on this yet. The stars rise "vertically" --straight "up" from the horizon-- at the equator, at every azimuth (compass) direction. And about twelve hours later, they also set vertically. The challenge then is to figure out what they do in between rising and setting. I don't have time for more detail today, but I hope some other NavList members will have more to add."

    I'm disappointed that you received no further replies from 'some other NavList members' as I suggested above. Sadly, this community is dying.

    I think most of us are still suffering from stiff necks trying to work it out.  Not me; I’m still slaving away on “The Lincolnshire Lad who Named Australia Australia” due to be delivered in 10 days’ time.
    Would you believe there’s nowhere online I can steal a diagram of the route of the second breadfruit voyage?  I’m having to read whole chapters and draw the diagram myself.

    Well, I suppose Polaris stops where it is on the northern horizon with Kochab circling around it (when you can see it).  Stars on the celestial equator like Alnilam will rise in the east and go straight over your head and down the other side.  Stars in the northern celestial hemisphere will follow shallow parabolas reaching their maximum altitude of 90
    °- declination when due north of you.  Stars in the southern celestial hemisphere will do the same with respect to south.  Now the interesting bit, will the stars rise and set at an angle left or right of east and west equal to some function of their declination?  I suspect the angle is their declination e.g. Alnilam = almost zero degrees off, Polaris = 90 degrees off.  It would be nice to prove it for the stars in between, but I darn ’t leave Flinders and his blinking cat.  DaveP

       
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