NGC 6684, located approximately 44 million light-years away in the constellation Pavo, is a unique and captivating lenticular galaxy. Recently discovered during the Hubble Space Telescope’s ongoing survey of galaxies, NGC 6684 stands out due to its distinct characteristics that differentiate it from our own Milky Way.
Unlike the Milky Way, which is a classic spiral galaxy consisting of rotating arms filled with stars, NGC 6684 displays a ghostly, hazy shape. It belongs to a class of galaxies called lenticular galaxies, which resemble a lens when viewed from the side. While lenticular galaxies possess a central bulge of stars, they lack spiral arms and instead have a disk of stars.
Scientists have found that lenticular galaxies tend to contain older stars compared to spiral galaxies. They theorize that these galaxies may be aging spiral galaxies that have lost their spiral arms or spiral galaxies that have gone through mergers. The discovery of NGC 6684, along with other lenticular galaxies observed the Hubble Space Telescope such as NGC 1023, NGC 5283, and NGC 3489, provides valuable insights into the evolution of galaxies.
Although NGC 6684 is too distant to be visible with amateur telescopes, there is another captivating galaxy that can be easily spotted in the night sky. The Andromeda galaxy, also known as M31, can be observed in the eastern sky during late September and early October. As the closest major galaxy to the Milky Way, Andromeda is a splendid spiral galaxy that can be seen with the naked eye in dark skies or with stargazing binoculars.
Interestingly, astronomers predict that in approximately 4 billion years, the Andromeda galaxy will collide with the Milky Way, resulting in the combination of the two galaxies. This cosmic event will provide future skywatchers with an extraordinary view of the merged galaxies.