It can even bring galaxies so close that they begin to tug at one another, causing them to abandon their former identities and merge to form a single accumulation of gas, dust and stars. In this Hubble Space Telescope image is one such interaction where a galaxy called IC 1727 is currently interacting with its near neighbor galaxy, NGC 672 (which is just out of frame). The pair’s interactions have triggered peculiar and intriguing phenomena within both objects — most noticeably in IC 1727. The galaxy’s structure is visibly twisted and asymmetric, and its bright nucleus has been dragged off-center. In interacting galaxies such as these, astronomers often see signs of intense star formation (in episodic flurries known as starbursts) and spot newly-formed star clusters. They are thought to be caused by gravity churning, redistributing and compacting the gas and dust. In fact, astronomers have analyzed the star formation within IC 1727 and NGC 672 and discovered something interesting — observations show that simultaneous bursts of star formation occurred in both galaxies some 20 to 30 and 450 to 750 million years ago. The most likely explanation for this is that the galaxies are indeed an interacting pair, approaching each other every so often and swirling up gas and dust as they pass close by. Image Credit: NASA/ESA
This edge-on view of a galaxy located about 45 million light-years away, showcases its beautiful arms, which swirl like a whirlpool around its bright central region.
February 04 | 2018
Astronomers took this image as they were observing an extraordinary exploding star – a supernova – near the galaxy’s central yellow core! The star rapidly evolved from a supernova containing very little hydrogen to one that is hydrogen-rich — in just one year. This rarely observed metamorphosis was luminous at high energies and provides unique insight into the poorly understood final phases of massive stars. By studying similar galaxies we hold a scientific mirror up to our own, allowing us to build a better understanding of our galactic environment, which we cannot always observe, and of galactic behavior and evolution as a whole. Credit: ESA/Hubble & NASA/D. Milisavljevic (Perdue University)