M 51

The Whirlpool Galaxy (M51), also known as Messier 51a or NGC 5194, is a classic spiral galaxy with a Seyfert 2 type active galaxy nucleus. It is located in the constellation Canes Venatici at a distance of about 23 million light-years from Earth. The galaxy is approximately 65 thousand light-years across. M51 is one of the brightest and most picturesque galaxies available to observe. It was discovered on October 13, 1773 by Charles Messier, who listed it in his catalog of astronomical objects under the number 51.

The unique structure of spiral arms of M51 was first noticed by William Parsons using the 72-inch telescope in Ireland. This galaxy became the first object classified as a spiral galaxy. Later, thanks to the research of Edwin Hubble, it was proven that spiral nebulae like M51 are separate galaxies.

The Whirlpool Galaxy interacts with a nearby satellite galaxy NGC 5195, which helps form its pronounced spiral structure. Research suggests that NGC 5195 has passed through the disk of M51 several times over the past hundreds of millions of years, creating various tidal structures, including a "northwest feather" that extends for 140 thousand light years. M51 is known for its high rate of star formation, especially in the central region and along the spiral arms. Despite this, the star formation efficiency is only about 1%, which is in line with the average for other galaxies. The current rate of star formation may continue for about 100 million years. Three supernovae have been recorded in the Whirlpool Galaxy: SN 1994I, ...