M94 is a face-on spiral galaxy whose spiral arms hug the middle and wind very tightly into the core. It is sometimes called the Cat’s Eye galaxy or the or Croc’s Eye Galaxy. It is about 16 million light years from the Earth. Around the brilliant circular disk is a ring of active star-forming regions, revealed in astrophotography as blue young star clusters. This artifact delineates it from the faded outer ring of an older yellowish stellar population.
For contrast, here is the very loosely wound spiral galaxy M101, also called the Pinwheel Galaxy. The galaxy has an unusually high number of H II gaseous regions, where new stars form, and many of these regions are bright and large, ionized by many extremely luminous and hot young stars. Three of these were bright enough to get their own designations in the New General Catalogue: NGC 5461, NGC 5462 and NGC 5471. M101 is about 21 million light years from the Earth and is about twice as large as our Milky Way. In fact, it is one of the biggest disc galaxies known. Shining with the light of about 30 billion suns, the Pinwheel galaxy is known as one of the most prominent Grand Design spiral galaxies in the sky – even if it is just a little lopsided…
Notice the much smaller and fainter spiral galaxy NGC 5477, the smudge just up from the bottom of the image. It is also about 22 million light years away from us. NGC 5471 is the turquoise/bluish “star” about midway between NGC 5477 and the central core of M101. It is also about the same distance away from us.
(Here’s a screenshot of a section of a star map showing the various separately named objects:
