Polaris (alpha UMi, alpha Ursae Minoris, Alpha Ursae Minors, commonly North Star, Northern Star or Pole Star, also Lodestar, sometimes Guiding star) is the brightest multiple star in the constellation and the 45th brightest star in the night sky. It is very close to the north celestial pole, making it the current northern pole star.
Because of its importance in celestial navigation, Polaris is known by numerous names. It became known as Polaris during the Renaissance, its name derived from the Latin Polaris "of/near the (north) pole".
Because alpha UMi lies nearly in a direct line with the axis of the Earth's rotation "above" the North Pole, Polaris stands almost motionless in the pole sky and all the stars of the Northern sky appear to rotate around it. Therefore, it makes an excellent fixed point from which to draw measurements for celestial navigation and for astrometry.
On March 22nd, 2007 the endodontic world lost an extraordinary professional. I lost a wonderful colleague and I lost a friend. Dr. Thomas Charles Dumsha, or Dr. D. as I called him, was an accomplished scholar and devoted mentor. Thom was memorable. Thom was genuine. Much of what I know about the specialty of endodontics and beyond the field of dentistry, Dr. D. Taught me. It is to him that I dedicate this office, TCD Endodontics.