north celestial pole view: now and in 87+ years!

Event Date: September 6th
Time: 9:00 PM


Brief

   Yesterday, I featured Polaris and the north celestial pole (n.c.p.) when talking about the Big Dipper.  Although the Dipper stars of Dubhe and Merak point almost in the direction of Polaris when a line is drawn through both, that same line to the n.c.p. is not quite as direct.  As the first image shows zoomed in with a 1.4º field, Polaris is shown at the edge (circumference) of this field.  Take a look, and the other stars when viewing with a dark sky.  Polaris is precisely 40.9 arc-minutes from the celestial pole...or is it??  See the detailed section for more on that!

Detailed

As hinted above, Polaris is not always the same separation from the n.c.p.  We can recall what I said about precession during the spring, meaning that as all other stars are doing, Polaris is changing in declination slightly each year, over the course of about 26,000 years.  In September 2099 for example, Polaris will reach its maximum declination of 89º 32 527', which according the software, is the highest numerical value.  This will put it less than 28 arc-minutes (1/2º) from the n.c.p., and make those aligning their telescopes most happy!  That is, using it as a guide star in an eyepiece that shows a dim field of stars, it helps recognize patterns closer to Polaris, and getting as close as possible to the n.c.p. before doing any further star aligning; such is common with go-to telescopes.
For the fun of it, I will show the image for September 14th, 2099.  This date and the 28th of that same month of that year, have Polaris at the aforementioned peak-declination, or very close to it both times anyway. 

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Notice the position difference of Polaris, using the same field as in image one.  For the first one especially, with Polaris barely within the field, can you recognize patterns that will help find the pole?  It is labeled in that image, yet not the second one, since Polaris is closer.  Eyeballing the field in image two however, do you notice which star shown is closest to the n.c.p.?