Ursa Major including the Big Dipper

Event Date: March 22nd
Time: 9:00 PM

Brief

   Yesterday, I brought up the talk of asterisms when showing the Sickle of Leo: stars that make a recognizable shape or figure within a constellation.  I also threw out a teaser for today's entry, regarding a much more recognizable asterism in comparison to the "backwards question mark", that represents Sickle as the Lion's mane.  For this evening, the Big Dipper is my asterism of discussion, and perhaps arguably, the most popular in the sky.  As a challenge for some viewers to imagine, the Dipper makes up the body and stretched tail of Ursa Major-- the Big Bear.  Both the Dipper alone and with the stick figure of the Bear, are shown in the images for this entry in that order, at the end of this section.  As it can be seen, the handle and "cup" portions of the Dipper can be easily seen with only seven stars.  These stars came from the same molecular cloud and therefore, all about the same magnitude and within a small range of distance from the Sun; small in comparison to stars of other asterisms, anyway.  The stars are labeled in the image, and range in magnitude from 1.8 for Alkaid, to 3.3 for Megrez.

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

Detailed

   The Big Dipper, which is much easier to see than the rest of the stars which make up Ursa Major, has been a favorite of northern-hemisphere viewers for a second reason, besides the configuration of the stars: it is seen as circumpolar.  As the animation in this final link shows, the stars are far north near the axis.  As seen from most northern latitudes, the Dipper stars are above the horizon 24 hours, 7 days a week.  For northern latitudes close to the equator, they are above the horizon most hours, although perhaps too close to it, to see easily if any obstruction.  From the southern hemisphere, depending on how far south a person views from, the Dipper is seen either as long as 12 hours a night (nearest to the equator where nights barely are that long) to not at all (the south pole).
  As we talk more about latitude as this series progresses, I will consistently put the celestial grid in the image, as I have above; it can be seen in image 1 this evening, and as shown, least-northern Alkaid is the only star that just barely sinks below the horizon...albeit less than three hours.  Any star seen at our latitude that is of declination 53º N or greater, is circumpolar.  This is figured by a simple calculation: 90º minus our latitude (about 38º).  Since we are just a bit south of the 38º mark (37º 49' 09"), that translates exactly to 52º 10' 51") for the difference.  Stars at this declination would graze the horizon.  Therefore, if about a degree further north, with both an obstruction-free horizon and from a high elevation, the stars of the Dipper bright enough to be visible through atmospheric pollution, and perhaps be seen with the eye alone.
Enjoy the Dipper, and if you are a night owl, watch it curve high in the sky directly north, before starting come low again very gradually.