Y Canum Venaticorum appears as a deep red star, because it has a very carbon-rich atmosphere which absorbs the blue part of the light. Therefore, the cool red giant star is easy to identify by its color, although there are only a few bright stars in its vicinity. Its brightness varies from 4.8 to 6.4m, in average it takes 157 days between two maxima. 710 light-years separate us from the star, which is called „La Superba“ (the Superior) since the 19th Century.
At 5.9m, M 3 is one of the three brightest globular clusters in the northern sky. At a distance of 34,000 light-years more than 45,000 stars form a ball with a diameter of 150 light-years, which can only be resolved into individual stars with a telescope. In binoculars, the 15 arcmin large globular cluster appears only as a blurred star. Although M 3 is about 10 billion years old, it still contains dark regions that are caused by gas clouds. Due to its age, M 3 should not contain any more gas clouds. It contains an unusual number of young, blue stars, and the number of variables is also unusually high.
Also known as the Whirlpool-Galaxy, M 51 is perhaps the most photographed pair of galaxies. The sight of this duo disappoints regularly even in large telescopes. In binoculars, you can at least see a faint shimmer of eighth magnitude with a star-like core, which is located 3.5° southwest of the outermost star of the handle of the Big Dipper (η Ursae Majoris). If you use at least 10x magnification, you may spot the companion galaxy NGC 5195 as a “bump“. The spiral structure was first recognized by Lord Rosse in a 72-inch telescope in 1845, making M 51 the first spiral nebula which was ever recognized as such. Until 1923 the 11 arcminutes large galaxy was thought to be a rotating gaseous nebula from which a new star with a planetary system will arise. Only with the observations of the Andromeda galaxy by Edwin Hubble in 1923, the spiral nebulae were identified as galaxies with billions of stars – before, the scientists believed these nebulae to be part of our own galaxy.
M 51 is the larger of the two, the smaller NGC 5195 circles around it. 56 million years ago, the two galaxies were closest to each other. Today, NGC 5195 is behind M 51. A bridge of stars connects the two galaxies.
M 94 is located about halfway between α and β Canum Venaticorum and is quite inconspicuous. With 8.2m, it is not very bright, but because it is rather compact with 10 × 12 arc minutes, you can still see it quite well – the brightness is distributed over a relatively small area. Most light of this 30,000 light-years large galaxy comes from the core, therefore it will only at a higher magnification appear no longer only as a star, but surrounded by a slight shimmer. 21 million light-years separate us from M 94.
M 106 can be found in 10 × 50 binoculars as quite an extensive shimmer in the west of a 6m star. At least the brighter core of the 8 × 18 arcminutes large galaxy should be visible. Because it is quite large, M 106 appears darker than the 8.3m which it has according to the catalog data. It is a barred spiral galaxy with very tightly wound arms. The 22 million light-years distant galaxy is also a strong radio source